diff --git a/bazel/testing/lit.cfg.py b/bazel/testing/lit.cfg.py
index 825d1c15e28b..466dd6e40629 100644
--- a/bazel/testing/lit.cfg.py
+++ b/bazel/testing/lit.cfg.py
@@ -6,6 +6,7 @@ SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 
 import lit.formats
 import os
+from pathlib import Path
 
 
 # This is a provided variable, ignore the undefined name warning.
@@ -13,47 +14,63 @@ config = config  # noqa: F821
 
 
 def fullpath(relative_path):
-    return os.path.join(os.environ["TEST_SRCDIR"], relative_path)
+    return Path(os.environ["TEST_SRCDIR"]).joinpath(relative_path)
+
+
+def add_substitution(before, after):
+    """Adds a substitution to the config. Wraps before as `%{before}`."""
+    config.substitutions.append((f"%{{{before}}}", after))
+
+
+def add_substitutions():
+    """Adds required substitutions to the config."""
+    tools = {
+        "carbon": fullpath("carbon/toolchain/driver/carbon"),
+        "explorer": fullpath("carbon/explorer/explorer"),
+        "explorer_prelude": fullpath("carbon/explorer/data/prelude.carbon"),
+        "filecheck": fullpath("llvm-project/llvm/FileCheck"),
+        "not": fullpath("llvm-project/llvm/not"),
+        "merge_output": fullpath("carbon/bazel/testing/merge_output"),
+    }
+
+    run_carbon = f"{tools['merge_output']} {tools['carbon']}"
+    run_explorer = (
+        f"{tools['merge_output']} {tools['explorer']} %s "
+        f"--prelude={tools['explorer_prelude']}"
+    )
+    filecheck_allow_unmatched = (
+        f"{tools['filecheck']} %s --match-full-lines --strict-whitespace"
+    )
+    filecheck_strict = (
+        f"{filecheck_allow_unmatched} --implicit-check-not={{{{.}}}}"
+    )
+
+    add_substitution("carbon", f"{tools['merge_output']} {tools['carbon']}")
+    add_substitution(
+        "carbon-run-parser",
+        f"{run_carbon} dump parse-tree %s | {filecheck_strict}",
+    )
+    add_substitution(
+        "carbon-run-semantics",
+        f"{run_carbon} dump semantics-ir %s | {filecheck_strict}",
+    )
+    add_substitution(
+        "carbon-run-tokens", f"{run_carbon} dump tokens %s | {filecheck_strict}"
+    )
+    add_substitution(
+        "explorer-run",
+        f"{run_explorer} | {filecheck_strict}",
+    )
+    add_substitution(
+        "explorer-run-trace",
+        f"{run_explorer} --parser_debug --trace_file=- | "
+        f"{filecheck_allow_unmatched}",
+    )
+    add_substitution("FileCheck-strict", filecheck_strict)
+    add_substitution("not", tools["not"])
 
 
 config.name = "lit"
 config.suffixes = [".carbon"]
 config.test_format = lit.formats.ShTest()
-
-_MERGE_OUTPUT = fullpath("carbon/bazel/testing/merge_output")
-
-config.substitutions.append(
-    (
-        "%{carbon}",
-        "%s %s" % (_MERGE_OUTPUT, fullpath("carbon/toolchain/driver/carbon")),
-    )
-)
-_EXPLORER = "%s %s --prelude=%s" % (
-    _MERGE_OUTPUT,
-    fullpath("carbon/explorer/explorer"),
-    fullpath("carbon/explorer/data/prelude.carbon"),
-)
-config.substitutions.append(("%{explorer}", _EXPLORER))
-config.substitutions.append(
-    ("%{explorer-trace}", _EXPLORER + " --parser_debug --trace_file=-")
-)
-
-config.substitutions.append(("%{not}", fullpath("llvm-project/llvm/not")))
-
-_FILE_CHECK = "%s --dump-input-filter=all" % fullpath(
-    "llvm-project/llvm/FileCheck"
-)
-config.substitutions.append(("%{FileCheck}", _FILE_CHECK))
-config.substitutions.append(
-    (
-        "%{FileCheck-allow-unmatched}",
-        _FILE_CHECK + " --match-full-lines --strict-whitespace",
-    )
-)
-config.substitutions.append(
-    (
-        "%{FileCheck-strict}",
-        _FILE_CHECK
-        + " --implicit-check-not={{.}} --match-full-lines --strict-whitespace",
-    )
-)
+add_substitutions()
diff --git a/bazel/testing/lit_autoupdate_base.py b/bazel/testing/lit_autoupdate_base.py
index 6e4f5fcd28d7..0d042c55bff0 100755
--- a/bazel/testing/lit_autoupdate_base.py
+++ b/bazel/testing/lit_autoupdate_base.py
@@ -11,7 +11,6 @@ SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 from abc import ABC, abstractmethod
 import argparse
 from concurrent import futures
-import logging
 import os
 from pathlib import Path
 import re
@@ -19,45 +18,61 @@ import subprocess
 from typing import Any, Dict, List, NamedTuple, Optional, Pattern, Set, Tuple
 
 # A prefix followed by a command to run for autoupdating checked output.
-AUTOUPDATE_MARKER = "// AUTOUPDATE: "
+AUTOUPDATE_MARKER = "// AUTOUPDATE"
 
 # Indicates no autoupdate is requested.
 NOAUTOUPDATE_MARKER = "// NOAUTOUPDATE"
 
 # Standard replacements normally done in lit.cfg.py.
 MERGE_OUTPUT = "./bazel-bin/bazel/testing/merge_output"
-LIT_REPLACEMENTS = [
-    ("%{carbon}", f"{MERGE_OUTPUT} ./bazel-bin/toolchain/driver/carbon"),
-    ("%{explorer}", f"{MERGE_OUTPUT} ./bazel-bin/explorer/explorer"),
-]
+
+
+class Tool(NamedTuple):
+    build_target: str
+    autoupdate_cmd: List[str]
+
+
+tools = {
+    "carbon": Tool(
+        "//toolchain/driver:carbon",
+        [MERGE_OUTPUT, "./bazel-bin/toolchain/driver/carbon"],
+    ),
+    "explorer": Tool(
+        "//explorer",
+        [MERGE_OUTPUT, "./bazel-bin/explorer/explorer"],
+    ),
+}
 
 
 class ParsedArgs(NamedTuple):
+    autoupdate_args: List[str]
     build_mode: str
-    build_target: str
     extra_check_replacements: List[Tuple[Pattern, Pattern, str]]
     line_number_format: str
     line_number_pattern: Pattern
+    lit_run: List[str]
     testdata: str
     tests: List[Path]
+    tool: str
 
 
 def parse_args() -> ParsedArgs:
     """Parses command-line arguments and flags."""
     parser = argparse.ArgumentParser(description=__doc__)
     parser.add_argument("tests", nargs="*")
+    parser.add_argument(
+        "--autoupdate_arg",
+        metavar="COMMAND",
+        default=[],
+        action="append",
+        help="Optional arguments to pass to the autoupdate command.",
+    )
     parser.add_argument(
         "--build_mode",
         metavar="MODE",
         default="opt",
         help="The build mode to use. Defaults to opt for faster execution.",
     )
-    parser.add_argument(
-        "--build_target",
-        metavar="TARGET",
-        required=True,
-        help="The target to build.",
-    )
     parser.add_argument(
         "--extra_check_replacement",
         nargs=3,
@@ -80,6 +95,13 @@ def parse_args() -> ParsedArgs:
         help="A regular expression which matches line numbers to update as its "
         "only group.",
     )
+    parser.add_argument(
+        "--lit_run",
+        metavar="COMMAND",
+        required=True,
+        action="append",
+        help="RUN lines to set.",
+    )
     parser.add_argument(
         "--testdata",
         metavar="PATH",
@@ -87,19 +109,28 @@ def parse_args() -> ParsedArgs:
         help="The path to the testdata to update, relative to the workspace "
         "root.",
     )
+    parser.add_argument(
+        "--tool",
+        metavar="TOOL",
+        required=True,
+        choices=tools.keys(),
+        help="The tool being tested.",
+    )
     parsed_args = parser.parse_args()
     extra_check_replacements = [
         (re.compile(line_matcher), re.compile(before), after)
         for line_matcher, before, after in parsed_args.extra_check_replacement
     ]
     return ParsedArgs(
+        autoupdate_args=parsed_args.autoupdate_arg,
         build_mode=parsed_args.build_mode,
-        build_target=parsed_args.build_target,
         extra_check_replacements=extra_check_replacements,
         line_number_format=parsed_args.line_number_format,
         line_number_pattern=re.compile(parsed_args.line_number_pattern),
+        lit_run=parsed_args.lit_run,
         testdata=parsed_args.testdata,
         tests=[Path(test).resolve() for test in parsed_args.tests],
+        tool=parsed_args.tool,
     )
 
 
@@ -139,6 +170,16 @@ class OriginalLine(Line):
         return self.text
 
 
+class RunLine(Line):
+    """A RUN line."""
+
+    def __init__(self, text: str) -> None:
+        self.text = text
+
+    def format(self, **kwargs: Any) -> str:
+        return self.text
+
+
 class CheckLine(Line):
     """A `// CHECK:` line generated from the test output.
 
@@ -179,23 +220,17 @@ class CheckLine(Line):
         return f"{self.indent}// CHECK:{result}\n"
 
 
-class Autoupdate(NamedTuple):
-    line_number: int
-    cmd: str
-
-
-def find_autoupdate(test: str, orig_lines: List[str]) -> Optional[Autoupdate]:
+def find_autoupdate(test: str, orig_lines: List[str]) -> Optional[int]:
     """Figures out whether autoupdate should occur.
 
-    For AUTOUPDATE, returns the line and command. For NOAUTOUPDATE, returns
-    None.
+    For AUTOUPDATE, returns the line. For NOAUTOUPDATE, returns None.
     """
     found = 0
     result = None
     for line_number, line in enumerate(orig_lines):
         if line.startswith(AUTOUPDATE_MARKER):
             found += 1
-            result = Autoupdate(line_number, line[len(AUTOUPDATE_MARKER) :])
+            result = line_number
         elif line.startswith(NOAUTOUPDATE_MARKER):
             found += 1
     if found == 0:
@@ -219,23 +254,16 @@ def replace_all(s: str, replacements: List[Tuple[str, str]]) -> str:
 
 
 def get_matchable_test_output(
-    parsed_args: ParsedArgs,
-    test: str,
-    autoupdate_cmd: str,
+    autoupdate_args: List[str],
     extra_check_replacements: List[Tuple[Pattern, Pattern, str]],
+    tool: str,
+    test: str,
 ) -> List[str]:
     """Runs the autoupdate command and returns the output lines."""
-    # Mirror lit.cfg.py substitutions; bazel runs don't need --prelude.
-    # Also replaces `%s` with the test file.
-    autoupdate_cmd = replace_all(
-        autoupdate_cmd, [("%s", test)] + LIT_REPLACEMENTS
-    )
-
     # Run the autoupdate command to generate output.
     # (`bazel run` would serialize)
     p = subprocess.run(
-        autoupdate_cmd,
-        shell=True,
+        tools[tool].autoupdate_cmd + autoupdate_args + [test],
         stdout=subprocess.PIPE,
         stderr=subprocess.STDOUT,
     )
@@ -263,9 +291,17 @@ def get_matchable_test_output(
     return out_lines
 
 
+def is_replaced(line: str) -> bool:
+    """Returns true if autoupdate should replace the line."""
+    line = line.lstrip()
+    return line.startswith("// CHECK") or line.startswith("// RUN:")
+
+
 def merge_lines(
     line_number_format: str,
     line_number_pattern: Pattern,
+    lit_run: List[str],
+    test: str,
     autoupdate_line_number: int,
     raw_orig_lines: List[str],
     out_lines: List[str],
@@ -274,8 +310,7 @@ def merge_lines(
     orig_lines = [
         OriginalLine(i, line)
         for i, line in enumerate(raw_orig_lines)
-        # Remove CHECK lines in the original output.
-        if not line.lstrip().startswith("// CHECK")
+        if not is_replaced(line)
     ]
     check_lines = [
         CheckLine(out_line, line_number_format, line_number_pattern)
@@ -286,6 +321,11 @@ def merge_lines(
     # CHECK lines must go after AUTOUPDATE.
     while orig_lines and orig_lines[0].line_number <= autoupdate_line_number:
         result_lines.append(orig_lines.pop(0))
+    for line in lit_run:
+        run_not = ""
+        if Path(test).name.startswith("fail_"):
+            run_not = "%{not} "
+        result_lines.append(RunLine(f"// RUN: {run_not}{line}\n"))
     # Interleave the original lines and the CHECK: lines.
     while orig_lines and check_lines:
         # Original lines go first when the CHECK line is known and later.
@@ -315,21 +355,23 @@ def update_check(parsed_args: ParsedArgs, test: Path) -> bool:
         orig_lines = f.readlines()
 
     # Make sure we're supposed to autoupdate.
-    autoupdate = find_autoupdate(str(test), orig_lines)
-    if autoupdate is None:
+    autoupdate_line = find_autoupdate(str(test), orig_lines)
+    if autoupdate_line is None:
         return False
 
     # Determine the merged output lines.
     out_lines = get_matchable_test_output(
-        parsed_args,
-        str(test),
-        autoupdate.cmd,
+        parsed_args.autoupdate_args,
         parsed_args.extra_check_replacements,
+        parsed_args.tool,
+        str(test),
     )
     result_lines = merge_lines(
         parsed_args.line_number_format,
         parsed_args.line_number_pattern,
-        autoupdate.line_number,
+        parsed_args.lit_run,
+        str(test),
+        autoupdate_line,
         orig_lines,
         out_lines,
     )
@@ -369,8 +411,8 @@ def update_checks(parsed_args: ParsedArgs, tests: Set[Path]) -> None:
     def map_helper(test: Path) -> bool:
         try:
             updated = update_check(parsed_args, test)
-        except Exception:
-            logging.exception(f"Failed to update {test}")
+        except Exception as e:
+            raise ValueError(f"Failed to update {test}") from e
         print(".", end="", flush=True)
         return updated
 
@@ -406,7 +448,7 @@ def main() -> None:
             "-c",
             parsed_args.build_mode,
             "//bazel/testing:merge_output",
-            parsed_args.build_target,
+            tools[parsed_args.tool].build_target,
         ]
     )
 
diff --git a/explorer/README.md b/explorer/README.md
index 33e893181b07..4df9976b2d2d 100644
--- a/explorer/README.md
+++ b/explorer/README.md
@@ -72,9 +72,9 @@ boilerplate at the top:
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:result: 0
 
 package ExplorerTest api;
@@ -83,23 +83,16 @@ package ExplorerTest api;
 To explain this boilerplate:
 
 -   The standard copyright is expected.
+-   The `AUTOUPDATE` line indicates that `RUN` and `CHECK` lines will be
+    automatically inserted immediately below by the `./lit_autoupdate.py`
+    script.
 -   The `RUN` lines indicate two commands for `lit` to execute using the file:
     one without trace and debug output, one with.
-    -   Output is piped to `FileCheck` for verification.
-    -   Setting `-allow-unused-prefixes` to false when processing the ordinary
-        output, and true when handling the trace output, allows us to omit the
-        tracing output from the `CHECK` lines, while ensuring they cover all
-        non-tracing output.
-    -   Setting `-match-full-lines` in both cases indicates that each `CHECK`
-        line must match a complete output line, with no extra characters before
-        or after the `CHECK` pattern.
     -   `RUN:` will be followed by the `not` command when failure is expected.
         In particular, `RUN: not explorer ...`.
-    -   `%s` is a
-        [`lit` substitution](https://llvm.org/docs/CommandGuide/lit.html#substitutions)
-        for the path to the given test file.
--   The `AUTOUPDATE` line indicates that `CHECK` lines will be automatically
-    inserted immediately below by the `./lit_autoupdate.py` script.
+    -   The full command is in `lit.cfg.py`; it will run explorer and pass
+        results to
+        [`FileCheck`](https://llvm.org/docs/CommandGuide/FileCheck.html).
 -   The `CHECK` lines indicate expected output, verified by `FileCheck`.
     -   Where a `CHECK` line contains text like `{{.*}}`, the double curly
         braces indicate a contained regular expression.
diff --git a/explorer/lit_autoupdate.py b/explorer/lit_autoupdate.py
index 545023510435..8946ecd1b338 100755
--- a/explorer/lit_autoupdate.py
+++ b/explorer/lit_autoupdate.py
@@ -14,8 +14,8 @@ from pathlib import Path
 
 
 def main() -> None:
-    # Calls the main script with explorer settings. This uses execv in order to
-    # avoid Python import behaviors.
+    # Calls the main script using execv in order to avoid Python import
+    # behaviors.
     this_py = Path(__file__).resolve()
     actual_py = this_py.parent.parent.joinpath(
         "bazel", "testing", "lit_autoupdate_base.py"
@@ -23,12 +23,11 @@ def main() -> None:
     args = [
         sys.argv[0],
         # Flags to configure for explorer testing.
-        "--build_target",
-        "//explorer",
-        "--testdata",
-        "explorer/testdata",
-        "--line_number_pattern",
-        r"(?<=\.carbon:)(\d+)(?=(?:\D|$))",
+        "--tool=explorer",
+        "--testdata=explorer/testdata",
+        r"--line_number_pattern=(?<=\.carbon:)(\d+)(?=(?:\D|$))",
+        "--lit_run=%{explorer-run}",
+        "--lit_run=%{explorer-run-trace}",
     ] + sys.argv[1:]
     os.execv(actual_py, args)
 
diff --git a/explorer/testdata/addr/fail_method_let.carbon b/explorer/testdata/addr/fail_method_let.carbon
index 1114c712357d..293b6e01c795 100644
--- a/explorer/testdata/addr/fail_method_let.carbon
+++ b/explorer/testdata/addr/fail_method_let.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/addr/fail_method_me_misspelled.carbon b/explorer/testdata/addr/fail_method_me_misspelled.carbon
index b895fcef9942..2de5a0fbf401 100644
--- a/explorer/testdata/addr/fail_method_me_misspelled.carbon
+++ b/explorer/testdata/addr/fail_method_me_misspelled.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/addr/fail_method_me_type.carbon b/explorer/testdata/addr/fail_method_me_type.carbon
index 49c2e7d17a6c..bdd5c64a798f 100644
--- a/explorer/testdata/addr/fail_method_me_type.carbon
+++ b/explorer/testdata/addr/fail_method_me_type.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/addr/method.carbon b/explorer/testdata/addr/method.carbon
index 7848e5191756..b9dc607ea94c 100644
--- a/explorer/testdata/addr/method.carbon
+++ b/explorer/testdata/addr/method.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/addr/nested_method.carbon b/explorer/testdata/addr/nested_method.carbon
index 419d85677a27..388421724f64 100644
--- a/explorer/testdata/addr/nested_method.carbon
+++ b/explorer/testdata/addr/nested_method.carbon
@@ -3,9 +3,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/alias/class_alias.carbon b/explorer/testdata/alias/class_alias.carbon
index dbf1fc8be0bb..694c9a398b5d 100644
--- a/explorer/testdata/alias/class_alias.carbon
+++ b/explorer/testdata/alias/class_alias.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: b.n: 1
 // CHECK:STDOUT: d.Get(0): 2
 // CHECK:STDOUT: e.Get(1): 3
diff --git a/explorer/testdata/alias/fail_alias_expression.carbon b/explorer/testdata/alias/fail_alias_expression.carbon
index 1a0a15a314a8..1a751587f74c 100644
--- a/explorer/testdata/alias/fail_alias_expression.carbon
+++ b/explorer/testdata/alias/fail_alias_expression.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/alias/fail_alias_var.carbon b/explorer/testdata/alias/fail_alias_var.carbon
index 6338fe63036d..1356a499b2fe 100644
--- a/explorer/testdata/alias/fail_alias_var.carbon
+++ b/explorer/testdata/alias/fail_alias_var.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/alias/fail_self_alias.carbon b/explorer/testdata/alias/fail_self_alias.carbon
index 5a00d2d56c3b..d9a5462907b6 100644
--- a/explorer/testdata/alias/fail_self_alias.carbon
+++ b/explorer/testdata/alias/fail_self_alias.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/alias/function_alias.carbon b/explorer/testdata/alias/function_alias.carbon
index b6e4a19b3067..39f5153a6f38 100644
--- a/explorer/testdata/alias/function_alias.carbon
+++ b/explorer/testdata/alias/function_alias.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 7
 
 package ExplorerTest api;
diff --git a/explorer/testdata/alias/interface_alias.carbon b/explorer/testdata/alias/interface_alias.carbon
index 802593f60f73..0c9c5f28634b 100644
--- a/explorer/testdata/alias/interface_alias.carbon
+++ b/explorer/testdata/alias/interface_alias.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 12345
 
 package ExplorerTest api;
diff --git a/explorer/testdata/alias/member_name_alias.carbon b/explorer/testdata/alias/member_name_alias.carbon
index a6cd83539eee..b941c255931f 100644
--- a/explorer/testdata/alias/member_name_alias.carbon
+++ b/explorer/testdata/alias/member_name_alias.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/alias/struct_alias.carbon b/explorer/testdata/alias/struct_alias.carbon
index 9ed04b4cbfeb..a8562423ff55 100644
--- a/explorer/testdata/alias/struct_alias.carbon
+++ b/explorer/testdata/alias/struct_alias.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: ab.a: 2
 // CHECK:STDOUT: ab.b: 1
 // CHECK:STDOUT: ba.a: 2
diff --git a/explorer/testdata/alias/type_alias.carbon b/explorer/testdata/alias/type_alias.carbon
index d40fbf044d44..1e1364eea475 100644
--- a/explorer/testdata/alias/type_alias.carbon
+++ b/explorer/testdata/alias/type_alias.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 4
 
 package ExplorerTest api;
diff --git a/explorer/testdata/array/fail_index.carbon b/explorer/testdata/array/fail_index.carbon
index 1b86d10479e4..3f9e1a0e4c86 100644
--- a/explorer/testdata/array/fail_index.carbon
+++ b/explorer/testdata/array/fail_index.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/array/fail_negative_size.carbon b/explorer/testdata/array/fail_negative_size.carbon
index 192326090947..52abf2407dc9 100644
--- a/explorer/testdata/array/fail_negative_size.carbon
+++ b/explorer/testdata/array/fail_negative_size.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/array/fail_size_mismatch.carbon b/explorer/testdata/array/fail_size_mismatch.carbon
index bbeb767cdb48..62e9e453d997 100644
--- a/explorer/testdata/array/fail_size_mismatch.carbon
+++ b/explorer/testdata/array/fail_size_mismatch.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/array/index.carbon b/explorer/testdata/array/index.carbon
index 1a9baa5cf33f..42d34586df8c 100644
--- a/explorer/testdata/array/index.carbon
+++ b/explorer/testdata/array/index.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/array/nested.carbon b/explorer/testdata/array/nested.carbon
index e2ae42643710..766502b6a382 100644
--- a/explorer/testdata/array/nested.carbon
+++ b/explorer/testdata/array/nested.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/as/as_same_type.carbon b/explorer/testdata/as/as_same_type.carbon
index 311b475dc7bf..ed035c669abc 100644
--- a/explorer/testdata/as/as_same_type.carbon
+++ b/explorer/testdata/as/as_same_type.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 5
 
 package ExplorerTest api;
diff --git a/explorer/testdata/as/convert.carbon b/explorer/testdata/as/convert.carbon
index 0782c1d833a8..1e1a07e4c5a7 100644
--- a/explorer/testdata/as/convert.carbon
+++ b/explorer/testdata/as/convert.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 5
 
 package ExplorerTest api;
diff --git a/explorer/testdata/as/fail_destination_not_type.carbon b/explorer/testdata/as/fail_destination_not_type.carbon
index d694a4a9c7bc..96a8b2cc844d 100644
--- a/explorer/testdata/as/fail_destination_not_type.carbon
+++ b/explorer/testdata/as/fail_destination_not_type.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/as/fail_no_conversion.carbon b/explorer/testdata/as/fail_no_conversion.carbon
index e954686522bc..79ff74d8ad1d 100644
--- a/explorer/testdata/as/fail_no_conversion.carbon
+++ b/explorer/testdata/as/fail_no_conversion.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/as/implicit_as.carbon b/explorer/testdata/as/implicit_as.carbon
index af6509084836..5315f7f8caca 100644
--- a/explorer/testdata/as/implicit_as.carbon
+++ b/explorer/testdata/as/implicit_as.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 5
 
 package ExplorerTest api;
diff --git a/explorer/testdata/assert/assert.carbon b/explorer/testdata/assert/fail_assert.carbon
similarity index 79%
rename from explorer/testdata/assert/assert.carbon
rename to explorer/testdata/assert/fail_assert.carbon
index 11837bae89b8..84940c6de298 100644
--- a/explorer/testdata/assert/assert.carbon
+++ b/explorer/testdata/assert/fail_assert.carbon
@@ -5,9 +5,10 @@
 // This won't auto-update because it uses a regex for the prelude line number,
 // so that it doesn't need to be updated on every prelude change.
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
+// This can't be autoupdated because the error line comes form a different file.
 // NOAUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 // CHECK:STDERR: RUNTIME ERROR: {{.*}}/explorer/data/prelude.carbon:{{.*}}: "HALLO WELT"
 
 package ExplorerTest api;
diff --git a/explorer/testdata/assign/convert_rhs.carbon b/explorer/testdata/assign/convert_rhs.carbon
index 2dd5a7679b5e..d31ab9bfd2df 100644
--- a/explorer/testdata/assign/convert_rhs.carbon
+++ b/explorer/testdata/assign/convert_rhs.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 1
 
 package ExplorerTest api;
diff --git a/explorer/testdata/assign/destruct_original.carbon b/explorer/testdata/assign/destruct_original.carbon
index 7ab9d7cae3f2..cfe6015c0452 100644
--- a/explorer/testdata/assign/destruct_original.carbon
+++ b/explorer/testdata/assign/destruct_original.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/assign/reassign_original.carbon b/explorer/testdata/assign/reassign_original.carbon
index b758cb42c487..9afc8b5cd42f 100644
--- a/explorer/testdata/assign/reassign_original.carbon
+++ b/explorer/testdata/assign/reassign_original.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/assoc_const/fail_anonymous.carbon b/explorer/testdata/assoc_const/fail_anonymous.carbon
index e2cb37ece2b5..9eab2a36020a 100644
--- a/explorer/testdata/assoc_const/fail_anonymous.carbon
+++ b/explorer/testdata/assoc_const/fail_anonymous.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/assoc_const/fail_incomplete_impl_1.carbon b/explorer/testdata/assoc_const/fail_incomplete_impl_1.carbon
index 6961b6467784..8c3c4a743ae6 100644
--- a/explorer/testdata/assoc_const/fail_incomplete_impl_1.carbon
+++ b/explorer/testdata/assoc_const/fail_incomplete_impl_1.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/assoc_const/fail_incomplete_impl_2.carbon b/explorer/testdata/assoc_const/fail_incomplete_impl_2.carbon
index 2cc63a58e3f2..2e1c2faf1de1 100644
--- a/explorer/testdata/assoc_const/fail_incomplete_impl_2.carbon
+++ b/explorer/testdata/assoc_const/fail_incomplete_impl_2.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/assoc_const/fail_indirectly_equal.carbon b/explorer/testdata/assoc_const/fail_indirectly_equal.carbon
index 999b73b0b9c4..56474bcad7c7 100644
--- a/explorer/testdata/assoc_const/fail_indirectly_equal.carbon
+++ b/explorer/testdata/assoc_const/fail_indirectly_equal.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/assoc_const/fail_match_in_deduction.carbon b/explorer/testdata/assoc_const/fail_match_in_deduction.carbon
index b23b0a8f2cc5..c2e541825a52 100644
--- a/explorer/testdata/assoc_const/fail_match_in_deduction.carbon
+++ b/explorer/testdata/assoc_const/fail_match_in_deduction.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 // TODO: Should this work?
 
diff --git a/explorer/testdata/assoc_const/fail_multi_impl_scoping.carbon b/explorer/testdata/assoc_const/fail_multi_impl_scoping.carbon
index 59c5ac4f58bb..98f0898c390a 100644
--- a/explorer/testdata/assoc_const/fail_multi_impl_scoping.carbon
+++ b/explorer/testdata/assoc_const/fail_multi_impl_scoping.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/assoc_const/fail_multiple_deduction.carbon b/explorer/testdata/assoc_const/fail_multiple_deduction.carbon
index 498f1f8e365b..6f52d6b80eba 100644
--- a/explorer/testdata/assoc_const/fail_multiple_deduction.carbon
+++ b/explorer/testdata/assoc_const/fail_multiple_deduction.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/assoc_const/fail_overspecified_impl.carbon b/explorer/testdata/assoc_const/fail_overspecified_impl.carbon
index 23c5068a8fd1..f36a5fcd60c1 100644
--- a/explorer/testdata/assoc_const/fail_overspecified_impl.carbon
+++ b/explorer/testdata/assoc_const/fail_overspecified_impl.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/assoc_const/fail_redefined.carbon b/explorer/testdata/assoc_const/fail_redefined.carbon
index 67c38a3fbe27..3886974aade3 100644
--- a/explorer/testdata/assoc_const/fail_redefined.carbon
+++ b/explorer/testdata/assoc_const/fail_redefined.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/assoc_const/fail_unknown_value.carbon b/explorer/testdata/assoc_const/fail_unknown_value.carbon
index c2dc2874cc8d..2b4d50ed25d4 100644
--- a/explorer/testdata/assoc_const/fail_unknown_value.carbon
+++ b/explorer/testdata/assoc_const/fail_unknown_value.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/assoc_const/fail_unknown_value_specified_in_constraint.carbon b/explorer/testdata/assoc_const/fail_unknown_value_specified_in_constraint.carbon
index 4ef7b220ca89..7701670391ff 100644
--- a/explorer/testdata/assoc_const/fail_unknown_value_specified_in_constraint.carbon
+++ b/explorer/testdata/assoc_const/fail_unknown_value_specified_in_constraint.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/assoc_const/impl_lookup.carbon b/explorer/testdata/assoc_const/impl_lookup.carbon
index 392e19018fd3..0714489fb3f4 100644
--- a/explorer/testdata/assoc_const/impl_lookup.carbon
+++ b/explorer/testdata/assoc_const/impl_lookup.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 1
 
 package ExplorerTest api;
diff --git a/explorer/testdata/assoc_const/implement.carbon b/explorer/testdata/assoc_const/implement.carbon
index db2454e6ef7f..f65f8c92de9b 100644
--- a/explorer/testdata/assoc_const/implement.carbon
+++ b/explorer/testdata/assoc_const/implement.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 2
 
 package ExplorerTest api;
diff --git a/explorer/testdata/assoc_const/lookup_in_rewrite.carbon b/explorer/testdata/assoc_const/lookup_in_rewrite.carbon
index 6a6a089837bd..c7d767e5499c 100644
--- a/explorer/testdata/assoc_const/lookup_in_rewrite.carbon
+++ b/explorer/testdata/assoc_const/lookup_in_rewrite.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: 1
 // CHECK:STDOUT: i32.Hash
 // CHECK:STDOUT: 0
diff --git a/explorer/testdata/assoc_const/member_of_value.carbon b/explorer/testdata/assoc_const/member_of_value.carbon
index fb1506356767..f51226b0c80a 100644
--- a/explorer/testdata/assoc_const/member_of_value.carbon
+++ b/explorer/testdata/assoc_const/member_of_value.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 2
 
 package ExplorerTest api;
diff --git a/explorer/testdata/assoc_const/simple_constraint.carbon b/explorer/testdata/assoc_const/simple_constraint.carbon
index 72c979695953..ec2cc6dc01a0 100644
--- a/explorer/testdata/assoc_const/simple_constraint.carbon
+++ b/explorer/testdata/assoc_const/simple_constraint.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 3
 
 package ExplorerTest api;
diff --git a/explorer/testdata/assoc_const/simple_equality.carbon b/explorer/testdata/assoc_const/simple_equality.carbon
index 11198f5013d0..5a98a31d8456 100644
--- a/explorer/testdata/assoc_const/simple_equality.carbon
+++ b/explorer/testdata/assoc_const/simple_equality.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/auto/fail_use_in_init.carbon b/explorer/testdata/auto/fail_use_in_init.carbon
index 782c955f19ed..b6049134a64e 100644
--- a/explorer/testdata/auto/fail_use_in_init.carbon
+++ b/explorer/testdata/auto/fail_use_in_init.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s 2>&1 | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s 2>&1 | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/basic_syntax/addition.carbon b/explorer/testdata/basic_syntax/addition.carbon
index 08c07673a66d..030c4c72461d 100644
--- a/explorer/testdata/basic_syntax/addition.carbon
+++ b/explorer/testdata/basic_syntax/addition.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 7
 
 package ExplorerTest api;
diff --git a/explorer/testdata/basic_syntax/choice.carbon b/explorer/testdata/basic_syntax/choice.carbon
index 8d6cbd3057e9..2d5c0cad3a3e 100644
--- a/explorer/testdata/basic_syntax/choice.carbon
+++ b/explorer/testdata/basic_syntax/choice.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/basic_syntax/fail_alternative_not_type.carbon b/explorer/testdata/basic_syntax/fail_alternative_not_type.carbon
index 65cc2727e909..73a86dfca2cb 100644
--- a/explorer/testdata/basic_syntax/fail_alternative_not_type.carbon
+++ b/explorer/testdata/basic_syntax/fail_alternative_not_type.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/basic_syntax/fail_alternative_uses_choice.carbon b/explorer/testdata/basic_syntax/fail_alternative_uses_choice.carbon
index d5d56ff427fb..233477526b45 100644
--- a/explorer/testdata/basic_syntax/fail_alternative_uses_choice.carbon
+++ b/explorer/testdata/basic_syntax/fail_alternative_uses_choice.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/basic_syntax/fail_assign_to_function.carbon b/explorer/testdata/basic_syntax/fail_assign_to_function.carbon
index 965d327f3b4f..32bfaf6420e2 100644
--- a/explorer/testdata/basic_syntax/fail_assign_to_function.carbon
+++ b/explorer/testdata/basic_syntax/fail_assign_to_function.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/basic_syntax/fail_assign_to_rval.carbon b/explorer/testdata/basic_syntax/fail_assign_to_rval.carbon
index 2b8f9d1ac921..88e7e6036e34 100644
--- a/explorer/testdata/basic_syntax/fail_assign_to_rval.carbon
+++ b/explorer/testdata/basic_syntax/fail_assign_to_rval.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/basic_syntax/fail_block.carbon b/explorer/testdata/basic_syntax/fail_block.carbon
index 9ca341011a42..689889a969b0 100644
--- a/explorer/testdata/basic_syntax/fail_block.carbon
+++ b/explorer/testdata/basic_syntax/fail_block.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/basic_syntax/fail_choice_no_parens.carbon b/explorer/testdata/basic_syntax/fail_choice_no_parens.carbon
index d2fbb08c5ecd..9989e4117453 100644
--- a/explorer/testdata/basic_syntax/fail_choice_no_parens.carbon
+++ b/explorer/testdata/basic_syntax/fail_choice_no_parens.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/basic_syntax/not_compare_precedence.carbon b/explorer/testdata/basic_syntax/fail_compare_precedence.carbon
similarity index 57%
rename from explorer/testdata/basic_syntax/not_compare_precedence.carbon
rename to explorer/testdata/basic_syntax/fail_compare_precedence.carbon
index 9644525585cd..a4b48cd8964e 100644
--- a/explorer/testdata/basic_syntax/not_compare_precedence.carbon
+++ b/explorer/testdata/basic_syntax/fail_compare_precedence.carbon
@@ -2,13 +2,13 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
 fn CompareBools(a: bool, b: bool) -> bool {
-  // CHECK:STDERR: SYNTAX ERROR: {{.*}}/explorer/testdata/basic_syntax/not_compare_precedence.carbon:[[@LINE+1]]: syntax error, unexpected EQUAL_EQUAL, expecting SEMICOLON
+  // CHECK:STDERR: SYNTAX ERROR: {{.*}}/explorer/testdata/basic_syntax/fail_compare_precedence.carbon:[[@LINE+1]]: syntax error, unexpected EQUAL_EQUAL, expecting SEMICOLON
   return not a == b;
 }
diff --git a/explorer/testdata/basic_syntax/fail_invalid_char.carbon b/explorer/testdata/basic_syntax/fail_invalid_char.carbon
index e1f271321545..bcd9f7b75af4 100644
--- a/explorer/testdata/basic_syntax/fail_invalid_char.carbon
+++ b/explorer/testdata/basic_syntax/fail_invalid_char.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 // CHECK:STDERR: SYNTAX ERROR: {{.*}}/explorer/testdata/basic_syntax/fail_invalid_char.carbon:[[@LINE+1]]: invalid character '\xEF' in source file.
 �
diff --git a/explorer/testdata/basic_syntax/fail_invalid_integer.carbon b/explorer/testdata/basic_syntax/fail_invalid_integer.carbon
index fa21f8f0a796..e5ff654954a9 100644
--- a/explorer/testdata/basic_syntax/fail_invalid_integer.carbon
+++ b/explorer/testdata/basic_syntax/fail_invalid_integer.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/basic_syntax/fail_invalid_integer_type.carbon b/explorer/testdata/basic_syntax/fail_invalid_integer_type.carbon
index 116f89ca4c7f..058266af004e 100644
--- a/explorer/testdata/basic_syntax/fail_invalid_integer_type.carbon
+++ b/explorer/testdata/basic_syntax/fail_invalid_integer_type.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/basic_syntax/fail_invalid_var_expression.carbon b/explorer/testdata/basic_syntax/fail_invalid_var_expression.carbon
index 8bb49b9a50d9..f0959a326566 100644
--- a/explorer/testdata/basic_syntax/fail_invalid_var_expression.carbon
+++ b/explorer/testdata/basic_syntax/fail_invalid_var_expression.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/basic_syntax/fail_missing_var.carbon b/explorer/testdata/basic_syntax/fail_missing_var.carbon
index 6f83db9c33b3..b5679a5ef351 100644
--- a/explorer/testdata/basic_syntax/fail_missing_var.carbon
+++ b/explorer/testdata/basic_syntax/fail_missing_var.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/basic_syntax/fail_nested_binding.carbon b/explorer/testdata/basic_syntax/fail_nested_binding.carbon
index 10d00f1bb02a..8fffb37c27fb 100644
--- a/explorer/testdata/basic_syntax/fail_nested_binding.carbon
+++ b/explorer/testdata/basic_syntax/fail_nested_binding.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/basic_syntax/fail_unimplemented_example.carbon b/explorer/testdata/basic_syntax/fail_unimplemented_example.carbon
index 2e9e1796177c..5b9624c0bfc9 100644
--- a/explorer/testdata/basic_syntax/fail_unimplemented_example.carbon
+++ b/explorer/testdata/basic_syntax/fail_unimplemented_example.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/basic_syntax/fail_unknown_intrinsic.carbon b/explorer/testdata/basic_syntax/fail_unknown_intrinsic.carbon
index 93954d65158c..bbfdf41878c5 100644
--- a/explorer/testdata/basic_syntax/fail_unknown_intrinsic.carbon
+++ b/explorer/testdata/basic_syntax/fail_unknown_intrinsic.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/basic_syntax/fail_unsupported_integer_type.carbon b/explorer/testdata/basic_syntax/fail_unsupported_integer_type.carbon
index c0ff44a69b9c..79ef4eace642 100644
--- a/explorer/testdata/basic_syntax/fail_unsupported_integer_type.carbon
+++ b/explorer/testdata/basic_syntax/fail_unsupported_integer_type.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/basic_syntax/fail_var_named_self.carbon b/explorer/testdata/basic_syntax/fail_var_named_self.carbon
index af27f25a9d57..1bf1c3c9ce37 100644
--- a/explorer/testdata/basic_syntax/fail_var_named_self.carbon
+++ b/explorer/testdata/basic_syntax/fail_var_named_self.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/basic_syntax/fail_var_type.carbon b/explorer/testdata/basic_syntax/fail_var_type.carbon
index 44b0ea064b5a..942575e2c0da 100644
--- a/explorer/testdata/basic_syntax/fail_var_type.carbon
+++ b/explorer/testdata/basic_syntax/fail_var_type.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/basic_syntax/next.carbon b/explorer/testdata/basic_syntax/next.carbon
index 5d3d3a1a798f..5d95d9d82c92 100644
--- a/explorer/testdata/basic_syntax/next.carbon
+++ b/explorer/testdata/basic_syntax/next.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/basic_syntax/placeholder_variable.carbon b/explorer/testdata/basic_syntax/placeholder_variable.carbon
index c8c8589e01d2..c6094c570b97 100644
--- a/explorer/testdata/basic_syntax/placeholder_variable.carbon
+++ b/explorer/testdata/basic_syntax/placeholder_variable.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/basic_syntax/record.carbon b/explorer/testdata/basic_syntax/record.carbon
index f62e4ee5a8b3..357138dbfea4 100644
--- a/explorer/testdata/basic_syntax/record.carbon
+++ b/explorer/testdata/basic_syntax/record.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/basic_syntax/star.carbon b/explorer/testdata/basic_syntax/star.carbon
index b6fdfebd8a50..af0b8e19462f 100644
--- a/explorer/testdata/basic_syntax/star.carbon
+++ b/explorer/testdata/basic_syntax/star.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/basic_syntax/trace.carbon b/explorer/testdata/basic_syntax/trace.carbon
index ee9b413e3870..6cac3175059b 100644
--- a/explorer/testdata/basic_syntax/trace.carbon
+++ b/explorer/testdata/basic_syntax/trace.carbon
@@ -2,12 +2,11 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-//
 // A lot of output is elided: this is only checking for a few things for simple
 // sanity checking on --parser_debug --trace_file=- output.
 //
 // NOAUTOUPDATE
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: ********** source program **********
 // CHECK:STDOUT: interface ImplicitAs {
 // CHECK:STDOUT: ********** type checking **********
diff --git a/explorer/testdata/basic_syntax/var_tuple.carbon b/explorer/testdata/basic_syntax/var_tuple.carbon
index c48cf58bed1d..adf7aacb6041 100644
--- a/explorer/testdata/basic_syntax/var_tuple.carbon
+++ b/explorer/testdata/basic_syntax/var_tuple.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/basic_syntax/zero.carbon b/explorer/testdata/basic_syntax/zero.carbon
index abe632ed587d..c967d4e7f108 100644
--- a/explorer/testdata/basic_syntax/zero.carbon
+++ b/explorer/testdata/basic_syntax/zero.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/block/empty.carbon b/explorer/testdata/block/empty.carbon
index 9afdf0ec73a6..d18cd280ca1f 100644
--- a/explorer/testdata/block/empty.carbon
+++ b/explorer/testdata/block/empty.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/block/shadowing.carbon b/explorer/testdata/block/shadowing.carbon
index 223ce90c5e9c..a860cd0fbde2 100644
--- a/explorer/testdata/block/shadowing.carbon
+++ b/explorer/testdata/block/shadowing.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/choice/fail_recursive_use.carbon b/explorer/testdata/choice/fail_recursive_use.carbon
index ff22a1b9093f..94799f0e8963 100644
--- a/explorer/testdata/choice/fail_recursive_use.carbon
+++ b/explorer/testdata/choice/fail_recursive_use.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s 2>&1 | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s 2>&1 | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/choice/generic_choice_multiple_template_arguments.carbon b/explorer/testdata/choice/generic_choice_multiple_template_arguments.carbon
index f620b3ab5b74..7b398c12fcb3 100644
--- a/explorer/testdata/choice/generic_choice_multiple_template_arguments.carbon
+++ b/explorer/testdata/choice/generic_choice_multiple_template_arguments.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 22
 
 package ExplorerTest api;
diff --git a/explorer/testdata/choice/generic_choice_nested_in_template_class.carbon b/explorer/testdata/choice/generic_choice_nested_in_template_class.carbon
index 5d04ce0222d2..b9732b6de098 100644
--- a/explorer/testdata/choice/generic_choice_nested_in_template_class.carbon
+++ b/explorer/testdata/choice/generic_choice_nested_in_template_class.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: H 22
 // CHECK:STDOUT: result: 0
 
diff --git a/explorer/testdata/choice/generic_choice_simple_assignment.carbon b/explorer/testdata/choice/generic_choice_simple_assignment.carbon
index fed4deef0ad8..b1c1f2f5bdab 100644
--- a/explorer/testdata/choice/generic_choice_simple_assignment.carbon
+++ b/explorer/testdata/choice/generic_choice_simple_assignment.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 22
 
 package ExplorerTest api;
diff --git a/explorer/testdata/class/assign.carbon b/explorer/testdata/class/assign.carbon
index da3dde1065a7..4e0c805e3dfa 100644
--- a/explorer/testdata/class/assign.carbon
+++ b/explorer/testdata/class/assign.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/class/assign_member.carbon b/explorer/testdata/class/assign_member.carbon
index eebc5220ac34..d76c76d9b8ce 100644
--- a/explorer/testdata/class/assign_member.carbon
+++ b/explorer/testdata/class/assign_member.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/class/bound_method.carbon b/explorer/testdata/class/bound_method.carbon
index 59a17bbc3700..588accab42fd 100644
--- a/explorer/testdata/class/bound_method.carbon
+++ b/explorer/testdata/class/bound_method.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/class/class_function.carbon b/explorer/testdata/class/class_function.carbon
index eeb4784325d4..ac663535794a 100644
--- a/explorer/testdata/class/class_function.carbon
+++ b/explorer/testdata/class/class_function.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/class/class_function_from_instance.carbon b/explorer/testdata/class/class_function_from_instance.carbon
index 65e9cc260099..09f061194212 100644
--- a/explorer/testdata/class/class_function_from_instance.carbon
+++ b/explorer/testdata/class/class_function_from_instance.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/class/class_function_self.carbon b/explorer/testdata/class/class_function_self.carbon
index 5bc7368af45e..0dbf1619badb 100644
--- a/explorer/testdata/class/class_function_self.carbon
+++ b/explorer/testdata/class/class_function_self.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/class/class_function_value.carbon b/explorer/testdata/class/class_function_value.carbon
index f0f00289bbc4..8017af0c54b5 100644
--- a/explorer/testdata/class/class_function_value.carbon
+++ b/explorer/testdata/class/class_function_value.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/class/empty_class.carbon b/explorer/testdata/class/empty_class.carbon
index 7abfd74bb729..883e893b8ebb 100644
--- a/explorer/testdata/class/empty_class.carbon
+++ b/explorer/testdata/class/empty_class.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/class/fail_abstract_class.carbon b/explorer/testdata/class/fail_abstract_class.carbon
index 7a4e026e5487..d018e7c7cf65 100644
--- a/explorer/testdata/class/fail_abstract_class.carbon
+++ b/explorer/testdata/class/fail_abstract_class.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/class/fail_base_class.carbon b/explorer/testdata/class/fail_base_class.carbon
index 58c8eff62f07..cb73ae7febad 100644
--- a/explorer/testdata/class/fail_base_class.carbon
+++ b/explorer/testdata/class/fail_base_class.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/class/fail_class_extends.carbon b/explorer/testdata/class/fail_class_extends.carbon
index e655c38c13c9..609deb1763bd 100644
--- a/explorer/testdata/class/fail_class_extends.carbon
+++ b/explorer/testdata/class/fail_class_extends.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/class/fail_class_named_self.carbon b/explorer/testdata/class/fail_class_named_self.carbon
index cb26a2dbea86..7db25800ff75 100644
--- a/explorer/testdata/class/fail_class_named_self.carbon
+++ b/explorer/testdata/class/fail_class_named_self.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/class/fail_field_access_mismatch.carbon b/explorer/testdata/class/fail_field_access_mismatch.carbon
index 609ad570931f..1e9e00b126c4 100644
--- a/explorer/testdata/class/fail_field_access_mismatch.carbon
+++ b/explorer/testdata/class/fail_field_access_mismatch.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/class/fail_field_mismatch.carbon b/explorer/testdata/class/fail_field_mismatch.carbon
index 87842b49a999..06f3184c7d10 100644
--- a/explorer/testdata/class/fail_field_mismatch.carbon
+++ b/explorer/testdata/class/fail_field_mismatch.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/class/fail_field_missing.carbon b/explorer/testdata/class/fail_field_missing.carbon
index 2a3a5380e087..86d0efe0f28b 100644
--- a/explorer/testdata/class/fail_field_missing.carbon
+++ b/explorer/testdata/class/fail_field_missing.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/class/fail_member_call_before_typecheck.carbon b/explorer/testdata/class/fail_member_call_before_typecheck.carbon
index dd20c4943010..97a42a0892be 100644
--- a/explorer/testdata/class/fail_member_call_before_typecheck.carbon
+++ b/explorer/testdata/class/fail_member_call_before_typecheck.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s 2>&1 | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s 2>&1 | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/class/fail_member_of_self.carbon b/explorer/testdata/class/fail_member_of_self.carbon
index abbef883c0d5..258ec47aac43 100644
--- a/explorer/testdata/class/fail_member_of_self.carbon
+++ b/explorer/testdata/class/fail_member_of_self.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s 2>&1 | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s 2>&1 | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/class/fail_method_deduced.carbon b/explorer/testdata/class/fail_method_deduced.carbon
index eb1e1f5b2339..3cd52bfff237 100644
--- a/explorer/testdata/class/fail_method_deduced.carbon
+++ b/explorer/testdata/class/fail_method_deduced.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/class/fail_method_from_class.carbon b/explorer/testdata/class/fail_method_from_class.carbon
index 5990ba04de9c..14cb1ca2a039 100644
--- a/explorer/testdata/class/fail_method_from_class.carbon
+++ b/explorer/testdata/class/fail_method_from_class.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/class/fail_method_in_var.carbon b/explorer/testdata/class/fail_method_in_var.carbon
index 98a139e404b0..fb23f06ee48c 100644
--- a/explorer/testdata/class/fail_method_in_var.carbon
+++ b/explorer/testdata/class/fail_method_in_var.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/class/fail_return_method.carbon b/explorer/testdata/class/fail_return_method.carbon
index 5477da64e299..0dbbc3f0f1ba 100644
--- a/explorer/testdata/class/fail_return_method.carbon
+++ b/explorer/testdata/class/fail_return_method.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/class/fail_use_before_typecheck.carbon b/explorer/testdata/class/fail_use_before_typecheck.carbon
index 500117bcfc73..6eacbd0e3503 100644
--- a/explorer/testdata/class/fail_use_before_typecheck.carbon
+++ b/explorer/testdata/class/fail_use_before_typecheck.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s 2>&1 | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s 2>&1 | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/class/function_param.carbon b/explorer/testdata/class/function_param.carbon
index efa6718d73da..cfe823b4bdb4 100644
--- a/explorer/testdata/class/function_param.carbon
+++ b/explorer/testdata/class/function_param.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/class/global_var.carbon b/explorer/testdata/class/global_var.carbon
index 835a2a637a2d..f4bce1f7452d 100644
--- a/explorer/testdata/class/global_var.carbon
+++ b/explorer/testdata/class/global_var.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/class/method.carbon b/explorer/testdata/class/method.carbon
index b357a3253331..1c8c9cfb4552 100644
--- a/explorer/testdata/class/method.carbon
+++ b/explorer/testdata/class/method.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/class/method_call_method.carbon b/explorer/testdata/class/method_call_method.carbon
index 9bc48733ec1d..10df7cf180c4 100644
--- a/explorer/testdata/class/method_call_method.carbon
+++ b/explorer/testdata/class/method_call_method.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/class/method_self.carbon b/explorer/testdata/class/method_self.carbon
index ce70599044bb..99f96c6ad78f 100644
--- a/explorer/testdata/class/method_self.carbon
+++ b/explorer/testdata/class/method_self.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/class/temp.carbon b/explorer/testdata/class/temp.carbon
index 8367bae2c518..01c7d64b813e 100644
--- a/explorer/testdata/class/temp.carbon
+++ b/explorer/testdata/class/temp.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/class/var.carbon b/explorer/testdata/class/var.carbon
index 3404c7fe5e9c..9c556e5257bf 100644
--- a/explorer/testdata/class/var.carbon
+++ b/explorer/testdata/class/var.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/comparison/builtin_comparsion.carbon b/explorer/testdata/comparison/builtin_comparsion.carbon
index 360850f17d55..7f42c42893b5 100644
--- a/explorer/testdata/comparison/builtin_comparsion.carbon
+++ b/explorer/testdata/comparison/builtin_comparsion.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: strings less: 1
 // CHECK:STDOUT: ints less: 0
 // CHECK:STDOUT: strings less eq: 1
diff --git a/explorer/testdata/comparison/builtin_equality.carbon b/explorer/testdata/comparison/builtin_equality.carbon
index 8864b8fb42ac..65b42092b75b 100644
--- a/explorer/testdata/comparison/builtin_equality.carbon
+++ b/explorer/testdata/comparison/builtin_equality.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: bool: 1
 // CHECK:STDOUT: bool: 1
 // CHECK:STDOUT: bool: 1
diff --git a/explorer/testdata/comparison/custom_equality.carbon b/explorer/testdata/comparison/custom_equality.carbon
index e61c1c44b1cc..4cf7152732cf 100644
--- a/explorer/testdata/comparison/custom_equality.carbon
+++ b/explorer/testdata/comparison/custom_equality.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: structs equal: 0
 // CHECK:STDOUT: structs not equal: 1
 // CHECK:STDOUT: result: 0
diff --git a/explorer/testdata/comparison/fail_empty_struct.carbon b/explorer/testdata/comparison/fail_empty_struct.carbon
index d00fae715c48..06d39a39393e 100644
--- a/explorer/testdata/comparison/fail_empty_struct.carbon
+++ b/explorer/testdata/comparison/fail_empty_struct.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/comparison/fail_no_impl.carbon b/explorer/testdata/comparison/fail_no_impl.carbon
index 365df8a965fa..70a4760c1851 100644
--- a/explorer/testdata/comparison/fail_no_impl.carbon
+++ b/explorer/testdata/comparison/fail_no_impl.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/constraint/binding_self.carbon b/explorer/testdata/constraint/binding_self.carbon
index fc45d31c7020..7d4bc74208a0 100644
--- a/explorer/testdata/constraint/binding_self.carbon
+++ b/explorer/testdata/constraint/binding_self.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 12
 
 package ExplorerTest api;
diff --git a/explorer/testdata/constraint/combined_interfaces.carbon b/explorer/testdata/constraint/combined_interfaces.carbon
index dbd04ecd3f8e..1f71d132f803 100644
--- a/explorer/testdata/constraint/combined_interfaces.carbon
+++ b/explorer/testdata/constraint/combined_interfaces.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 526
 
 package ExplorerTest api;
diff --git a/explorer/testdata/constraint/dot_self_is_other.carbon b/explorer/testdata/constraint/dot_self_is_other.carbon
index cd5290ac1046..0ec8729a9ca2 100644
--- a/explorer/testdata/constraint/dot_self_is_other.carbon
+++ b/explorer/testdata/constraint/dot_self_is_other.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 12
 
 package ExplorerTest api;
diff --git a/explorer/testdata/constraint/fail_ambiguous_member.carbon b/explorer/testdata/constraint/fail_ambiguous_member.carbon
index d6c45678adb7..afe39e07114a 100644
--- a/explorer/testdata/constraint/fail_ambiguous_member.carbon
+++ b/explorer/testdata/constraint/fail_ambiguous_member.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/constraint/no_combine_equality.carbon b/explorer/testdata/constraint/fail_combine_equality.carbon
similarity index 61%
rename from explorer/testdata/constraint/no_combine_equality.carbon
rename to explorer/testdata/constraint/fail_combine_equality.carbon
index 37bc9c640309..eac46b86e94f 100644
--- a/explorer/testdata/constraint/no_combine_equality.carbon
+++ b/explorer/testdata/constraint/fail_combine_equality.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
@@ -13,7 +13,7 @@ impl i32 as I {}
 
 fn F(A:! i32, B:! i32, C:! i32, D:! i32, E:! i32,
      T:! I where A == B and C == D and C == E and B == D) {
-  // CHECK:STDERR: COMPILATION ERROR: {{.*}}/explorer/testdata/constraint/no_combine_equality.carbon:[[@LINE+1]]: member access, F not in constraint interface I where T is interface I and A == B and C == D and C == E and B == D
+  // CHECK:STDERR: COMPILATION ERROR: {{.*}}/explorer/testdata/constraint/fail_combine_equality.carbon:[[@LINE+1]]: member access, F not in constraint interface I where T is interface I and A == B and C == D and C == E and B == D
   T.F();
 }
 
diff --git a/explorer/testdata/constraint/fail_dot_self_after_scope.carbon b/explorer/testdata/constraint/fail_dot_self_after_scope.carbon
index e55752b5527e..180bb7f4529d 100644
--- a/explorer/testdata/constraint/fail_dot_self_after_scope.carbon
+++ b/explorer/testdata/constraint/fail_dot_self_after_scope.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/constraint/fail_dot_self_after_scope_2.carbon b/explorer/testdata/constraint/fail_dot_self_after_scope_2.carbon
index 795036496707..35ee4830e160 100644
--- a/explorer/testdata/constraint/fail_dot_self_after_scope_2.carbon
+++ b/explorer/testdata/constraint/fail_dot_self_after_scope_2.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/constraint/fail_dot_self_not_in_scope.carbon b/explorer/testdata/constraint/fail_dot_self_not_in_scope.carbon
index c13ed86d1a45..2209834fa29c 100644
--- a/explorer/testdata/constraint/fail_dot_self_not_in_scope.carbon
+++ b/explorer/testdata/constraint/fail_dot_self_not_in_scope.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/constraint/fail_infinite_self.carbon b/explorer/testdata/constraint/fail_infinite_self.carbon
index 584d048872b2..346d47f82313 100644
--- a/explorer/testdata/constraint/fail_infinite_self.carbon
+++ b/explorer/testdata/constraint/fail_infinite_self.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/constraint/fail_infinite_self_ptr.carbon b/explorer/testdata/constraint/fail_infinite_self_ptr.carbon
index 0ca4dfdf76bd..e5dc47eefec0 100644
--- a/explorer/testdata/constraint/fail_infinite_self_ptr.carbon
+++ b/explorer/testdata/constraint/fail_infinite_self_ptr.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/constraint/missing_member.carbon b/explorer/testdata/constraint/fail_missing_member.carbon
similarity index 64%
rename from explorer/testdata/constraint/missing_member.carbon
rename to explorer/testdata/constraint/fail_missing_member.carbon
index be012c2d08e6..11ee0a5d8a41 100644
--- a/explorer/testdata/constraint/missing_member.carbon
+++ b/explorer/testdata/constraint/fail_missing_member.carbon
@@ -2,16 +2,16 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
 interface A { fn F() -> i32; }
 interface B { fn G() -> i32; }
 
-// CHECK:STDERR: COMPILATION ERROR: {{.*}}/explorer/testdata/constraint/missing_member.carbon:[[@LINE+1]]: member access, H not in constraint interface A & interface B where T is interface A and T is interface B
+// CHECK:STDERR: COMPILATION ERROR: {{.*}}/explorer/testdata/constraint/fail_missing_member.carbon:[[@LINE+1]]: member access, H not in constraint interface A & interface B where T is interface A and T is interface B
 fn Get[T:! A & B](n: T) -> i32 { return n.H(); }
 
 impl i32 as A {
diff --git a/explorer/testdata/constraint/fail_non_type_self.carbon b/explorer/testdata/constraint/fail_non_type_self.carbon
index 0c06f1d9ff2a..eb2ff5ef603b 100644
--- a/explorer/testdata/constraint/fail_non_type_self.carbon
+++ b/explorer/testdata/constraint/fail_non_type_self.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/constraint/fail_where_equals_different_types.carbon b/explorer/testdata/constraint/fail_where_equals_different_types.carbon
index 7965651aa3ec..96e71f1c99f0 100644
--- a/explorer/testdata/constraint/fail_where_equals_different_types.carbon
+++ b/explorer/testdata/constraint/fail_where_equals_different_types.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/constraint/fail_where_is_non_constraint.carbon b/explorer/testdata/constraint/fail_where_is_non_constraint.carbon
index cb3f76f65fe9..13b36c32da61 100644
--- a/explorer/testdata/constraint/fail_where_is_non_constraint.carbon
+++ b/explorer/testdata/constraint/fail_where_is_non_constraint.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/constraint/fail_where_is_non_type.carbon b/explorer/testdata/constraint/fail_where_is_non_type.carbon
index 1986f1ba98b7..95587d50b8e9 100644
--- a/explorer/testdata/constraint/fail_where_is_non_type.carbon
+++ b/explorer/testdata/constraint/fail_where_is_non_type.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/constraint/fail_where_non_type_is.carbon b/explorer/testdata/constraint/fail_where_non_type_is.carbon
index f7a85585f9ef..dfc9be5ec4c8 100644
--- a/explorer/testdata/constraint/fail_where_non_type_is.carbon
+++ b/explorer/testdata/constraint/fail_where_non_type_is.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/constraint/nondependent_where.carbon b/explorer/testdata/constraint/nondependent_where.carbon
index 3d514b1129ae..70ee4e7f2dd1 100644
--- a/explorer/testdata/constraint/nondependent_where.carbon
+++ b/explorer/testdata/constraint/nondependent_where.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 1
 
 package ExplorerTest api;
diff --git a/explorer/testdata/constraint/qualified_lookup_in_where.carbon b/explorer/testdata/constraint/qualified_lookup_in_where.carbon
index 3b892a2b3e73..dd3e20dbee17 100644
--- a/explorer/testdata/constraint/qualified_lookup_in_where.carbon
+++ b/explorer/testdata/constraint/qualified_lookup_in_where.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 122
 
 package ExplorerTest api;
diff --git a/explorer/testdata/constraint/rewrite.carbon b/explorer/testdata/constraint/rewrite.carbon
index fe454f76f2ba..5b03864680bb 100644
--- a/explorer/testdata/constraint/rewrite.carbon
+++ b/explorer/testdata/constraint/rewrite.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 12
 
 package ExplorerTest api;
diff --git a/explorer/testdata/constraint/rewrite_compound.carbon b/explorer/testdata/constraint/rewrite_compound.carbon
index 91a918c5cbd8..0785d67f96b0 100644
--- a/explorer/testdata/constraint/rewrite_compound.carbon
+++ b/explorer/testdata/constraint/rewrite_compound.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 1
 
 package ExplorerTest api;
diff --git a/explorer/testdata/constraint/rewrite_compound_2.carbon b/explorer/testdata/constraint/rewrite_compound_2.carbon
index 413c770f9351..2337bdd6c9c1 100644
--- a/explorer/testdata/constraint/rewrite_compound_2.carbon
+++ b/explorer/testdata/constraint/rewrite_compound_2.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 1
 
 package ExplorerTest api;
diff --git a/explorer/testdata/constraint/rewrite_in_qualifier.carbon b/explorer/testdata/constraint/rewrite_in_qualifier.carbon
index 42f9ca5d48dc..8ee5ae841cd5 100644
--- a/explorer/testdata/constraint/rewrite_in_qualifier.carbon
+++ b/explorer/testdata/constraint/rewrite_in_qualifier.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 2
 
 package ExplorerTest api;
diff --git a/explorer/testdata/constraint/rewrite_in_qualifier_and_type.carbon b/explorer/testdata/constraint/rewrite_in_qualifier_and_type.carbon
index eac4a8ecac91..e6e9d4ec8563 100644
--- a/explorer/testdata/constraint/rewrite_in_qualifier_and_type.carbon
+++ b/explorer/testdata/constraint/rewrite_in_qualifier_and_type.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 3
 
 package ExplorerTest api;
diff --git a/explorer/testdata/constraint/where_self.carbon b/explorer/testdata/constraint/where_self.carbon
index 3eeee87416ba..afd8ef3ef569 100644
--- a/explorer/testdata/constraint/where_self.carbon
+++ b/explorer/testdata/constraint/where_self.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 12
 
 package ExplorerTest api;
diff --git a/explorer/testdata/destructor/call_destructor_from_destructor.carbon b/explorer/testdata/destructor/call_destructor_from_destructor.carbon
index b252bf6b0828..74bd72accd61 100644
--- a/explorer/testdata/destructor/call_destructor_from_destructor.carbon
+++ b/explorer/testdata/destructor/call_destructor_from_destructor.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: DESTRUCTOR A 1
 // CHECK:STDOUT: DESTRUCTOR B 2
 // CHECK:STDOUT: DESTRUCTOR A 3
diff --git a/explorer/testdata/destructor/destructor_with_return.carbon b/explorer/testdata/destructor/destructor_with_return.carbon
index b6a6095b0457..66f1f3787347 100644
--- a/explorer/testdata/destructor/destructor_with_return.carbon
+++ b/explorer/testdata/destructor/destructor_with_return.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: DESTRUCTOR A 3
 // CHECK:STDOUT: result: 1
 
diff --git a/explorer/testdata/destructor/fail_multiple_destructor_declaration.carbon b/explorer/testdata/destructor/fail_multiple_destructor_declaration.carbon
index 8f8ce1f66fbd..b98d53ee2198 100644
--- a/explorer/testdata/destructor/fail_multiple_destructor_declaration.carbon
+++ b/explorer/testdata/destructor/fail_multiple_destructor_declaration.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/destructor/function_with_return.carbon b/explorer/testdata/destructor/function_with_return.carbon
index a207ddd17266..6b703f01a419 100644
--- a/explorer/testdata/destructor/function_with_return.carbon
+++ b/explorer/testdata/destructor/function_with_return.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: DESTRUCTOR C 1
 // CHECK:STDOUT: DESTRUCTOR B 2
 // CHECK:STDOUT: DESTRUCTOR A 3
diff --git a/explorer/testdata/destructor/loop_block.carbon b/explorer/testdata/destructor/loop_block.carbon
index 98c578de14d1..67b23ad3cc65 100644
--- a/explorer/testdata/destructor/loop_block.carbon
+++ b/explorer/testdata/destructor/loop_block.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: DESTRUCTOR A 1
 // CHECK:STDOUT: DESTRUCTOR A 2
 // CHECK:STDOUT: DESTRUCTOR A 3
diff --git a/explorer/testdata/destructor/loop_break_continue.carbon b/explorer/testdata/destructor/loop_break_continue.carbon
index 6ae7a6420235..8779a90a7bdb 100644
--- a/explorer/testdata/destructor/loop_break_continue.carbon
+++ b/explorer/testdata/destructor/loop_break_continue.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: DESTRUCTOR A 1
 // CHECK:STDOUT: DESTRUCTOR A 2
 // CHECK:STDOUT: DESTRUCTOR A 3
diff --git a/explorer/testdata/destructor/nested_block_with_return.carbon b/explorer/testdata/destructor/nested_block_with_return.carbon
index e81b18d97bc1..3a19d6380643 100644
--- a/explorer/testdata/destructor/nested_block_with_return.carbon
+++ b/explorer/testdata/destructor/nested_block_with_return.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: DESTRUCTOR A 1
 // CHECK:STDOUT: DESTRUCTOR A 2
 // CHECK:STDOUT: DESTRUCTOR A 3
diff --git a/explorer/testdata/experimental_continuation/await_maintains_scope.carbon b/explorer/testdata/experimental_continuation/await_maintains_scope.carbon
index 36a7610bdc16..6e0030ed0c69 100644
--- a/explorer/testdata/experimental_continuation/await_maintains_scope.carbon
+++ b/explorer/testdata/experimental_continuation/await_maintains_scope.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 3
 
 package ExplorerTest api;
diff --git a/explorer/testdata/experimental_continuation/convert_run.carbon b/explorer/testdata/experimental_continuation/convert_run.carbon
index b8146e88955d..2af35de8a7df 100644
--- a/explorer/testdata/experimental_continuation/convert_run.carbon
+++ b/explorer/testdata/experimental_continuation/convert_run.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 3
 
 package ExplorerTest api;
diff --git a/explorer/testdata/experimental_continuation/creation_is_noop.carbon b/explorer/testdata/experimental_continuation/creation_is_noop.carbon
index 6d16a5c1dcef..a9c70f023bac 100644
--- a/explorer/testdata/experimental_continuation/creation_is_noop.carbon
+++ b/explorer/testdata/experimental_continuation/creation_is_noop.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/experimental_continuation/fail_auto_return_await.carbon b/explorer/testdata/experimental_continuation/fail_auto_return_await.carbon
index ce1d3a61c606..d67bebd48876 100644
--- a/explorer/testdata/experimental_continuation/fail_auto_return_await.carbon
+++ b/explorer/testdata/experimental_continuation/fail_auto_return_await.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/experimental_continuation/fail_continuation_syntax.carbon b/explorer/testdata/experimental_continuation/fail_continuation_syntax.carbon
index 8788511c9231..5d1202cb5535 100644
--- a/explorer/testdata/experimental_continuation/fail_continuation_syntax.carbon
+++ b/explorer/testdata/experimental_continuation/fail_continuation_syntax.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/experimental_continuation/fail_lifetime.carbon b/explorer/testdata/experimental_continuation/fail_lifetime.carbon
index 11825f6bc0f5..e289eb22e43a 100644
--- a/explorer/testdata/experimental_continuation/fail_lifetime.carbon
+++ b/explorer/testdata/experimental_continuation/fail_lifetime.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/experimental_continuation/fail_recursive_continuation.carbon b/explorer/testdata/experimental_continuation/fail_recursive_continuation.carbon
index 345f1d9dcf33..91911ff1fedd 100644
--- a/explorer/testdata/experimental_continuation/fail_recursive_continuation.carbon
+++ b/explorer/testdata/experimental_continuation/fail_recursive_continuation.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/experimental_continuation/fail_return_in_continuation.carbon b/explorer/testdata/experimental_continuation/fail_return_in_continuation.carbon
index e8ff3b5a45be..69b8ee36d99e 100644
--- a/explorer/testdata/experimental_continuation/fail_return_in_continuation.carbon
+++ b/explorer/testdata/experimental_continuation/fail_return_in_continuation.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/experimental_continuation/recursive.carbon b/explorer/testdata/experimental_continuation/recursive.carbon
index 50e2ac50b63f..e0bfe8ca266e 100644
--- a/explorer/testdata/experimental_continuation/recursive.carbon
+++ b/explorer/testdata/experimental_continuation/recursive.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 10
 
 package ExplorerTest api;
diff --git a/explorer/testdata/experimental_continuation/run.carbon b/explorer/testdata/experimental_continuation/run.carbon
index 9c308016a952..e7d12e7ff19b 100644
--- a/explorer/testdata/experimental_continuation/run.carbon
+++ b/explorer/testdata/experimental_continuation/run.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 1
 
 package ExplorerTest api;
diff --git a/explorer/testdata/experimental_continuation/run_with_await.carbon b/explorer/testdata/experimental_continuation/run_with_await.carbon
index d7654b1fc831..9a9a26d0ce22 100644
--- a/explorer/testdata/experimental_continuation/run_with_await.carbon
+++ b/explorer/testdata/experimental_continuation/run_with_await.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 3
 
 package ExplorerTest api;
diff --git a/explorer/testdata/experimental_continuation/shallow_copy.carbon b/explorer/testdata/experimental_continuation/shallow_copy.carbon
index ffd9e0bc2a59..68462e6f2eef 100644
--- a/explorer/testdata/experimental_continuation/shallow_copy.carbon
+++ b/explorer/testdata/experimental_continuation/shallow_copy.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 3
 
 package ExplorerTest api;
diff --git a/explorer/testdata/for/for_loop.carbon b/explorer/testdata/for/for_loop.carbon
index 8435457cfe3d..b024ecbb0930 100644
--- a/explorer/testdata/for/for_loop.carbon
+++ b/explorer/testdata/for/for_loop.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: HALLO WELT 0
 // CHECK:STDOUT: HALLO WELT 1
 // CHECK:STDOUT: HALLO WELT 2
diff --git a/explorer/testdata/for/for_loop_auto.carbon b/explorer/testdata/for/for_loop_auto.carbon
index 21f5a742d418..c8128083c89d 100644
--- a/explorer/testdata/for/for_loop_auto.carbon
+++ b/explorer/testdata/for/for_loop_auto.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: HALLO WELT 0
 // CHECK:STDOUT: HALLO WELT 1
 // CHECK:STDOUT: HALLO WELT 2
diff --git a/explorer/testdata/for/for_loop_break.carbon b/explorer/testdata/for/for_loop_break.carbon
index 75dff02d8a4a..ce5c6558f70e 100644
--- a/explorer/testdata/for/for_loop_break.carbon
+++ b/explorer/testdata/for/for_loop_break.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 3
 
 package ExplorerTest api;
diff --git a/explorer/testdata/for/for_loop_continue.carbon b/explorer/testdata/for/for_loop_continue.carbon
index 2bf2f6232353..ec368dcdc8cf 100644
--- a/explorer/testdata/for/for_loop_continue.carbon
+++ b/explorer/testdata/for/for_loop_continue.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 4
 
 package ExplorerTest api;
diff --git a/explorer/testdata/for/for_loop_empty.carbon b/explorer/testdata/for/for_loop_empty.carbon
index 9363bbbbfa8f..6ebc10b00e58 100644
--- a/explorer/testdata/for/for_loop_empty.carbon
+++ b/explorer/testdata/for/for_loop_empty.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/for/for_loop_nested.carbon b/explorer/testdata/for/for_loop_nested.carbon
index 6d7d19d1f62f..9ed5fbc2cca7 100644
--- a/explorer/testdata/for/for_loop_nested.carbon
+++ b/explorer/testdata/for/for_loop_nested.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 20
 
 package ExplorerTest api;
diff --git a/explorer/testdata/function/auto_return/add.carbon b/explorer/testdata/function/auto_return/add.carbon
index bb1ca081fe02..370953f1e42c 100644
--- a/explorer/testdata/function/auto_return/add.carbon
+++ b/explorer/testdata/function/auto_return/add.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/function/auto_return/fail_direct_recurse.carbon b/explorer/testdata/function/auto_return/fail_direct_recurse.carbon
index 637e26bb574b..ba4befc08f7c 100644
--- a/explorer/testdata/function/auto_return/fail_direct_recurse.carbon
+++ b/explorer/testdata/function/auto_return/fail_direct_recurse.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/function/auto_return/fail_multiple_returns.carbon b/explorer/testdata/function/auto_return/fail_multiple_returns.carbon
index 81935bf80ac7..4c8c4ff02409 100644
--- a/explorer/testdata/function/auto_return/fail_multiple_returns.carbon
+++ b/explorer/testdata/function/auto_return/fail_multiple_returns.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/function/auto_return/fail_no_return.carbon b/explorer/testdata/function/auto_return/fail_no_return.carbon
index 2ae26baa9150..1fe8079f0b7a 100644
--- a/explorer/testdata/function/auto_return/fail_no_return.carbon
+++ b/explorer/testdata/function/auto_return/fail_no_return.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/function/auto_return/fail_separate_decl.carbon b/explorer/testdata/function/auto_return/fail_separate_decl.carbon
index e94cf51008a2..a677296d4cac 100644
--- a/explorer/testdata/function/auto_return/fail_separate_decl.carbon
+++ b/explorer/testdata/function/auto_return/fail_separate_decl.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/function/auto_return/modify_arg_type.carbon b/explorer/testdata/function/auto_return/modify_arg_type.carbon
index 948344123fbc..d59405cfbf36 100644
--- a/explorer/testdata/function/auto_return/modify_arg_type.carbon
+++ b/explorer/testdata/function/auto_return/modify_arg_type.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/function/auto_return/modify_return_type.carbon b/explorer/testdata/function/auto_return/modify_return_type.carbon
index 278e01e6fe90..ec065f2ef127 100644
--- a/explorer/testdata/function/auto_return/modify_return_type.carbon
+++ b/explorer/testdata/function/auto_return/modify_return_type.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/function/auto_return/type.carbon b/explorer/testdata/function/auto_return/type.carbon
index 64c62a306700..929abb38ecca 100644
--- a/explorer/testdata/function/auto_return/type.carbon
+++ b/explorer/testdata/function/auto_return/type.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/function/convert_args.carbon b/explorer/testdata/function/convert_args.carbon
index be7eb4771322..2899d6584f8f 100644
--- a/explorer/testdata/function/convert_args.carbon
+++ b/explorer/testdata/function/convert_args.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 123
 
 package ExplorerTest api;
diff --git a/explorer/testdata/function/empty_params.carbon b/explorer/testdata/function/empty_params.carbon
index 5292590e6483..b4fcee863efd 100644
--- a/explorer/testdata/function/empty_params.carbon
+++ b/explorer/testdata/function/empty_params.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/function/fail_call_undefined.carbon b/explorer/testdata/function/fail_call_undefined.carbon
index 5dfae2d3c527..f6e4bc97ac53 100644
--- a/explorer/testdata/function/fail_call_undefined.carbon
+++ b/explorer/testdata/function/fail_call_undefined.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s 2>&1 | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s 2>&1 | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/function/fail_call_undefined_main.carbon b/explorer/testdata/function/fail_call_undefined_main.carbon
index 95072c9e5c08..b20f37fc8a48 100644
--- a/explorer/testdata/function/fail_call_undefined_main.carbon
+++ b/explorer/testdata/function/fail_call_undefined_main.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s 2>&1 | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s 2>&1 | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 // CHECK:STDERR: RUNTIME ERROR: <Main()>:0: attempt to call function `Main` that has not been defined
 
 package ExplorerTest api;
diff --git a/explorer/testdata/function/fail_call_with_tuple.carbon b/explorer/testdata/function/fail_call_with_tuple.carbon
index 860b809330bc..d9612127ac64 100644
--- a/explorer/testdata/function/fail_call_with_tuple.carbon
+++ b/explorer/testdata/function/fail_call_with_tuple.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/function/fail_invalid_fnty.carbon b/explorer/testdata/function/fail_invalid_fnty.carbon
index 44df85be7a27..4181a0c097bd 100644
--- a/explorer/testdata/function/fail_invalid_fnty.carbon
+++ b/explorer/testdata/function/fail_invalid_fnty.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/function/fail_match_no_return.carbon b/explorer/testdata/function/fail_match_no_return.carbon
index 87172290ad70..c49d46dbeac0 100644
--- a/explorer/testdata/function/fail_match_no_return.carbon
+++ b/explorer/testdata/function/fail_match_no_return.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/function/fail_match_partial_return.carbon b/explorer/testdata/function/fail_match_partial_return.carbon
index 89a1bfeea9b9..8efa5d21dcc1 100644
--- a/explorer/testdata/function/fail_match_partial_return.carbon
+++ b/explorer/testdata/function/fail_match_partial_return.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/function/fail_non_exhaustive_match.carbon b/explorer/testdata/function/fail_non_exhaustive_match.carbon
index 91a70a8e0d88..9adb68412026 100644
--- a/explorer/testdata/function/fail_non_exhaustive_match.carbon
+++ b/explorer/testdata/function/fail_non_exhaustive_match.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/function/fail_parameter_type.carbon b/explorer/testdata/function/fail_parameter_type.carbon
index 8cd1ee03c259..f8f945e36cd8 100644
--- a/explorer/testdata/function/fail_parameter_type.carbon
+++ b/explorer/testdata/function/fail_parameter_type.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/function/fail_recurse_before_typecheck.carbon b/explorer/testdata/function/fail_recurse_before_typecheck.carbon
index d78facad6864..7f0a2db6d67c 100644
--- a/explorer/testdata/function/fail_recurse_before_typecheck.carbon
+++ b/explorer/testdata/function/fail_recurse_before_typecheck.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s 2>&1 | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s 2>&1 | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/function/fail_recurse_in_return_type.carbon b/explorer/testdata/function/fail_recurse_in_return_type.carbon
index d098f8a96350..b331345a6dc9 100644
--- a/explorer/testdata/function/fail_recurse_in_return_type.carbon
+++ b/explorer/testdata/function/fail_recurse_in_return_type.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s 2>&1 | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s 2>&1 | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/function/fail_return_call_has_invalid_body.carbon b/explorer/testdata/function/fail_return_call_has_invalid_body.carbon
index 7a57201a6df4..0584173901f9 100644
--- a/explorer/testdata/function/fail_return_call_has_invalid_body.carbon
+++ b/explorer/testdata/function/fail_return_call_has_invalid_body.carbon
@@ -2,8 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s 2>&1 2>&1 | %{FileCheck} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package EmptyIdentifier impl;
 
diff --git a/explorer/testdata/function/fail_var_type_is_call.carbon b/explorer/testdata/function/fail_var_type_is_call.carbon
index 1b73eb841bb1..021102ab8823 100644
--- a/explorer/testdata/function/fail_var_type_is_call.carbon
+++ b/explorer/testdata/function/fail_var_type_is_call.carbon
@@ -2,8 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s 2>&1 2>&1 | %{FileCheck} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package EmptyIdentifier impl;
 
diff --git a/explorer/testdata/function/fnty.carbon b/explorer/testdata/function/fnty.carbon
index 88ce979b9651..cf80290b587e 100644
--- a/explorer/testdata/function/fnty.carbon
+++ b/explorer/testdata/function/fnty.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/function/ignored_parameter.carbon b/explorer/testdata/function/ignored_parameter.carbon
index f9134eb0494d..b5b498fe6d85 100644
--- a/explorer/testdata/function/ignored_parameter.carbon
+++ b/explorer/testdata/function/ignored_parameter.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/function/multiple_args.carbon b/explorer/testdata/function/multiple_args.carbon
index 350bd8dc5c39..c7da9a507577 100644
--- a/explorer/testdata/function/multiple_args.carbon
+++ b/explorer/testdata/function/multiple_args.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/function/non_exhaustive_match_no_return_type.carbon b/explorer/testdata/function/non_exhaustive_match_no_return_type.carbon
index 4a50b4bc300b..e80b10c7b0fc 100644
--- a/explorer/testdata/function/non_exhaustive_match_no_return_type.carbon
+++ b/explorer/testdata/function/non_exhaustive_match_no_return_type.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/function/non_exhaustive_match_return.carbon b/explorer/testdata/function/non_exhaustive_match_return.carbon
index d330d1ad8fca..b9db5df5cc4a 100644
--- a/explorer/testdata/function/non_exhaustive_match_return.carbon
+++ b/explorer/testdata/function/non_exhaustive_match_return.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 1
 
 package ExplorerTest api;
diff --git a/explorer/testdata/function/param_lifetime.carbon b/explorer/testdata/function/param_lifetime.carbon
index 695dc86d0e34..e61ceb0a5252 100644
--- a/explorer/testdata/function/param_lifetime.carbon
+++ b/explorer/testdata/function/param_lifetime.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/function/recursive.carbon b/explorer/testdata/function/recursive.carbon
index e513deb1fff7..7f4fd9045135 100644
--- a/explorer/testdata/function/recursive.carbon
+++ b/explorer/testdata/function/recursive.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/function/return.carbon b/explorer/testdata/function/return.carbon
index d32058dc923d..ac3fba4dfad8 100644
--- a/explorer/testdata/function/return.carbon
+++ b/explorer/testdata/function/return.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/function/return_exhaustive_match.carbon b/explorer/testdata/function/return_exhaustive_match.carbon
index 0cecf5b0b8a4..49928a01bc4e 100644
--- a/explorer/testdata/function/return_exhaustive_match.carbon
+++ b/explorer/testdata/function/return_exhaustive_match.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 1
 
 package ExplorerTest api;
diff --git a/explorer/testdata/function/type_match.carbon b/explorer/testdata/function/type_match.carbon
index 4df72d6350cd..018ab24a0209 100644
--- a/explorer/testdata/function/type_match.carbon
+++ b/explorer/testdata/function/type_match.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/generic_class/class_function.carbon b/explorer/testdata/generic_class/class_function.carbon
index 237b2455ef78..f8fc0b8b24c7 100644
--- a/explorer/testdata/generic_class/class_function.carbon
+++ b/explorer/testdata/generic_class/class_function.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/generic_class/convert_from_struct.carbon b/explorer/testdata/generic_class/convert_from_struct.carbon
index 4d2e237e8044..9efd84bb80e3 100644
--- a/explorer/testdata/generic_class/convert_from_struct.carbon
+++ b/explorer/testdata/generic_class/convert_from_struct.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 5
 
 package ExplorerTest api;
diff --git a/explorer/testdata/generic_class/fail_args_mismatch.carbon b/explorer/testdata/generic_class/fail_args_mismatch.carbon
index 602cf33d99eb..30c9a0433824 100644
--- a/explorer/testdata/generic_class/fail_args_mismatch.carbon
+++ b/explorer/testdata/generic_class/fail_args_mismatch.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/generic_class/fail_argument_deduction.carbon b/explorer/testdata/generic_class/fail_argument_deduction.carbon
index 568d64e7aac4..e3f39b6b73be 100644
--- a/explorer/testdata/generic_class/fail_argument_deduction.carbon
+++ b/explorer/testdata/generic_class/fail_argument_deduction.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/generic_class/fail_bad_parameter_type.carbon b/explorer/testdata/generic_class/fail_bad_parameter_type.carbon
index 12ae4a8b0e4d..79e48fd9cc8e 100644
--- a/explorer/testdata/generic_class/fail_bad_parameter_type.carbon
+++ b/explorer/testdata/generic_class/fail_bad_parameter_type.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/generic_class/fail_field_access_on_generic.carbon b/explorer/testdata/generic_class/fail_field_access_on_generic.carbon
index dc471e51ba2d..20449e8b88ac 100644
--- a/explorer/testdata/generic_class/fail_field_access_on_generic.carbon
+++ b/explorer/testdata/generic_class/fail_field_access_on_generic.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/generic_class/fail_generic_class_arg.carbon b/explorer/testdata/generic_class/fail_generic_class_arg.carbon
index 4d0e52fe37a4..c1343888de39 100644
--- a/explorer/testdata/generic_class/fail_generic_class_arg.carbon
+++ b/explorer/testdata/generic_class/fail_generic_class_arg.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/generic_class/fail_generic_in_pattern.carbon b/explorer/testdata/generic_class/fail_generic_in_pattern.carbon
index 5e108db41666..19ab2e48870b 100644
--- a/explorer/testdata/generic_class/fail_generic_in_pattern.carbon
+++ b/explorer/testdata/generic_class/fail_generic_in_pattern.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/generic_class/fail_instantiate_non_generic.carbon b/explorer/testdata/generic_class/fail_instantiate_non_generic.carbon
index 54837234a470..7c90eb53edb0 100644
--- a/explorer/testdata/generic_class/fail_instantiate_non_generic.carbon
+++ b/explorer/testdata/generic_class/fail_instantiate_non_generic.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/generic_class/fail_no_args.carbon b/explorer/testdata/generic_class/fail_no_args.carbon
index f2d52778a2ad..ad19cd6d9e07 100644
--- a/explorer/testdata/generic_class/fail_no_args.carbon
+++ b/explorer/testdata/generic_class/fail_no_args.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/generic_class/fail_point_equal.carbon b/explorer/testdata/generic_class/fail_point_equal.carbon
index a9663354b9a8..8c8fc36ba3c7 100644
--- a/explorer/testdata/generic_class/fail_point_equal.carbon
+++ b/explorer/testdata/generic_class/fail_point_equal.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/generic_class/fail_return_type_is_type.carbon b/explorer/testdata/generic_class/fail_return_type_is_type.carbon
index 0922905a7d2a..42c93da9eef7 100644
--- a/explorer/testdata/generic_class/fail_return_type_is_type.carbon
+++ b/explorer/testdata/generic_class/fail_return_type_is_type.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/generic_class/fail_self_with_arg.carbon b/explorer/testdata/generic_class/fail_self_with_arg.carbon
index d736ec9d61f8..ea8d60801bb4 100644
--- a/explorer/testdata/generic_class/fail_self_with_arg.carbon
+++ b/explorer/testdata/generic_class/fail_self_with_arg.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/generic_class/fail_two_arg_lists.carbon b/explorer/testdata/generic_class/fail_two_arg_lists.carbon
index fdfad94db270..0b23bc8062dc 100644
--- a/explorer/testdata/generic_class/fail_two_arg_lists.carbon
+++ b/explorer/testdata/generic_class/fail_two_arg_lists.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/generic_class/fail_value_param_mismatch.carbon b/explorer/testdata/generic_class/fail_value_param_mismatch.carbon
index fe86420a7947..202521da6cd9 100644
--- a/explorer/testdata/generic_class/fail_value_param_mismatch.carbon
+++ b/explorer/testdata/generic_class/fail_value_param_mismatch.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/generic_class/generic_class_substitution.carbon b/explorer/testdata/generic_class/generic_class_substitution.carbon
index ebdef0955714..b0f4136f3d81 100644
--- a/explorer/testdata/generic_class/generic_class_substitution.carbon
+++ b/explorer/testdata/generic_class/generic_class_substitution.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/generic_class/generic_fun_and_class.carbon b/explorer/testdata/generic_class/generic_fun_and_class.carbon
index 9bbe4130996a..880460fbb596 100644
--- a/explorer/testdata/generic_class/generic_fun_and_class.carbon
+++ b/explorer/testdata/generic_class/generic_fun_and_class.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/generic_class/generic_point.carbon b/explorer/testdata/generic_class/generic_point.carbon
index 3a99c6eadcda..5fe771426dc3 100644
--- a/explorer/testdata/generic_class/generic_point.carbon
+++ b/explorer/testdata/generic_class/generic_point.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/generic_class/impl_with_argument.carbon b/explorer/testdata/generic_class/impl_with_argument.carbon
index c18f6ff8414b..f334393e5d52 100644
--- a/explorer/testdata/generic_class/impl_with_argument.carbon
+++ b/explorer/testdata/generic_class/impl_with_argument.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/generic_class/impl_with_self.carbon b/explorer/testdata/generic_class/impl_with_self.carbon
index dd2699e3b530..1f3a1cda4de8 100644
--- a/explorer/testdata/generic_class/impl_with_self.carbon
+++ b/explorer/testdata/generic_class/impl_with_self.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/generic_class/instantiation_at_compile_time.carbon b/explorer/testdata/generic_class/instantiation_at_compile_time.carbon
index 254855ec34fa..5d92b1dcfdfc 100644
--- a/explorer/testdata/generic_class/instantiation_at_compile_time.carbon
+++ b/explorer/testdata/generic_class/instantiation_at_compile_time.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/generic_class/param_with_dependent_type.carbon b/explorer/testdata/generic_class/param_with_dependent_type.carbon
index ee67e22dbab7..66acd2198a6a 100644
--- a/explorer/testdata/generic_class/param_with_dependent_type.carbon
+++ b/explorer/testdata/generic_class/param_with_dependent_type.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 1
 
 package ExplorerTest api;
diff --git a/explorer/testdata/generic_class/parameter_type_conversion.carbon b/explorer/testdata/generic_class/parameter_type_conversion.carbon
index c0fa95f5ac0e..15e853ae5e38 100644
--- a/explorer/testdata/generic_class/parameter_type_conversion.carbon
+++ b/explorer/testdata/generic_class/parameter_type_conversion.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 4
 
 package ExplorerTest api;
diff --git a/explorer/testdata/generic_class/point_with_interface.carbon b/explorer/testdata/generic_class/point_with_interface.carbon
index 192f9581cde9..74f1032cc32a 100644
--- a/explorer/testdata/generic_class/point_with_interface.carbon
+++ b/explorer/testdata/generic_class/point_with_interface.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/generic_class/use_at_compile_time.carbon b/explorer/testdata/generic_class/use_at_compile_time.carbon
index cea42334e516..9e5931ce11c2 100644
--- a/explorer/testdata/generic_class/use_at_compile_time.carbon
+++ b/explorer/testdata/generic_class/use_at_compile_time.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/generic_class/use_self.carbon b/explorer/testdata/generic_class/use_self.carbon
index 65de71b1c481..9fa4f2ac31f6 100644
--- a/explorer/testdata/generic_class/use_self.carbon
+++ b/explorer/testdata/generic_class/use_self.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/generic_function/apply.carbon b/explorer/testdata/generic_function/apply.carbon
index 9a6b75390938..c57b8d54cedb 100644
--- a/explorer/testdata/generic_function/apply.carbon
+++ b/explorer/testdata/generic_function/apply.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: -2
 
 package ExplorerTest api;
diff --git a/explorer/testdata/generic_function/call_at_compile_time.carbon b/explorer/testdata/generic_function/call_at_compile_time.carbon
index 161d0400acc0..1580c78a5b0c 100644
--- a/explorer/testdata/generic_function/call_at_compile_time.carbon
+++ b/explorer/testdata/generic_function/call_at_compile_time.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/generic_function/fail_implicit_conversion_extra_field.carbon b/explorer/testdata/generic_function/fail_implicit_conversion_extra_field.carbon
index 1aae3a384523..34db36d71fbf 100644
--- a/explorer/testdata/generic_function/fail_implicit_conversion_extra_field.carbon
+++ b/explorer/testdata/generic_function/fail_implicit_conversion_extra_field.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/generic_function/fail_implicit_conversion_missing_field.carbon b/explorer/testdata/generic_function/fail_implicit_conversion_missing_field.carbon
index b92e2f0519fe..33ad073c0528 100644
--- a/explorer/testdata/generic_function/fail_implicit_conversion_missing_field.carbon
+++ b/explorer/testdata/generic_function/fail_implicit_conversion_missing_field.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/generic_function/fail_missing_exclam.carbon b/explorer/testdata/generic_function/fail_missing_exclam.carbon
index be0cba6e2860..5753acd8763c 100644
--- a/explorer/testdata/generic_function/fail_missing_exclam.carbon
+++ b/explorer/testdata/generic_function/fail_missing_exclam.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/generic_function/fail_not_addable.carbon b/explorer/testdata/generic_function/fail_not_addable.carbon
index 34fc5aede12d..9db8cfbab5cb 100644
--- a/explorer/testdata/generic_function/fail_not_addable.carbon
+++ b/explorer/testdata/generic_function/fail_not_addable.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/generic_function/fail_not_type.carbon b/explorer/testdata/generic_function/fail_not_type.carbon
index c47b0f862829..c9d0febe2050 100644
--- a/explorer/testdata/generic_function/fail_not_type.carbon
+++ b/explorer/testdata/generic_function/fail_not_type.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/generic_function/fail_type_deduction_mismatch.carbon b/explorer/testdata/generic_function/fail_type_deduction_mismatch.carbon
index 8c3932a68602..c10cde3b96d6 100644
--- a/explorer/testdata/generic_function/fail_type_deduction_mismatch.carbon
+++ b/explorer/testdata/generic_function/fail_type_deduction_mismatch.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/generic_function/fail_type_deduction_unused.carbon b/explorer/testdata/generic_function/fail_type_deduction_unused.carbon
index 60bb6b929d7c..d3854a85446a 100644
--- a/explorer/testdata/generic_function/fail_type_deduction_unused.carbon
+++ b/explorer/testdata/generic_function/fail_type_deduction_unused.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/generic_function/fail_wrong_variable_substituation.carbon b/explorer/testdata/generic_function/fail_wrong_variable_substituation.carbon
index 5ffeabf064df..bc26ad198566 100644
--- a/explorer/testdata/generic_function/fail_wrong_variable_substituation.carbon
+++ b/explorer/testdata/generic_function/fail_wrong_variable_substituation.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package Foo api;
 
diff --git a/explorer/testdata/generic_function/generic_method.carbon b/explorer/testdata/generic_function/generic_method.carbon
index 68ecd2f3455d..545618901d0a 100644
--- a/explorer/testdata/generic_function/generic_method.carbon
+++ b/explorer/testdata/generic_function/generic_method.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/generic_function/implicit_conversion.carbon b/explorer/testdata/generic_function/implicit_conversion.carbon
index 802cfc4dca65..70f9421c318f 100644
--- a/explorer/testdata/generic_function/implicit_conversion.carbon
+++ b/explorer/testdata/generic_function/implicit_conversion.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 4213
 
 package ExplorerTest api;
diff --git a/explorer/testdata/generic_function/non_generic_param.carbon b/explorer/testdata/generic_function/non_generic_param.carbon
index 7c02cea2f4df..81c21bbfb965 100644
--- a/explorer/testdata/generic_function/non_generic_param.carbon
+++ b/explorer/testdata/generic_function/non_generic_param.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 1
 
 package ExplorerTest api;
diff --git a/explorer/testdata/generic_function/nondeduced_generic_param.carbon b/explorer/testdata/generic_function/nondeduced_generic_param.carbon
index 0791aa7d8d4b..7c1f0c8e667a 100644
--- a/explorer/testdata/generic_function/nondeduced_generic_param.carbon
+++ b/explorer/testdata/generic_function/nondeduced_generic_param.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 1
 
 package ExplorerTest api;
diff --git a/explorer/testdata/generic_function/return_val.carbon b/explorer/testdata/generic_function/return_val.carbon
index d2b908d436c1..95f1a460bc9b 100644
--- a/explorer/testdata/generic_function/return_val.carbon
+++ b/explorer/testdata/generic_function/return_val.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/generic_function/swap.carbon b/explorer/testdata/generic_function/swap.carbon
index 5920ca60cc67..e81da3015b99 100644
--- a/explorer/testdata/generic_function/swap.carbon
+++ b/explorer/testdata/generic_function/swap.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/generic_function/tuple_map.carbon b/explorer/testdata/generic_function/tuple_map.carbon
index 4593bafa1d1b..db6b128b455c 100644
--- a/explorer/testdata/generic_function/tuple_map.carbon
+++ b/explorer/testdata/generic_function/tuple_map.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 1
 
 package ExplorerTest api;
diff --git a/explorer/testdata/generic_function/type_matching.carbon b/explorer/testdata/generic_function/type_matching.carbon
index eedac35bce13..ae9581ce98dc 100644
--- a/explorer/testdata/generic_function/type_matching.carbon
+++ b/explorer/testdata/generic_function/type_matching.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/global_variable/fail_init_type_mismatch.carbon b/explorer/testdata/global_variable/fail_init_type_mismatch.carbon
index 83bf8e39f771..da26b55f5cfe 100644
--- a/explorer/testdata/global_variable/fail_init_type_mismatch.carbon
+++ b/explorer/testdata/global_variable/fail_init_type_mismatch.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/global_variable/fail_modify_in_constant_expr.carbon b/explorer/testdata/global_variable/fail_modify_in_constant_expr.carbon
index 7b224c95778d..baf296d6ec25 100644
--- a/explorer/testdata/global_variable/fail_modify_in_constant_expr.carbon
+++ b/explorer/testdata/global_variable/fail_modify_in_constant_expr.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/global_variable/fail_named_self.carbon b/explorer/testdata/global_variable/fail_named_self.carbon
index 94926ac9efd7..20052ad51ea2 100644
--- a/explorer/testdata/global_variable/fail_named_self.carbon
+++ b/explorer/testdata/global_variable/fail_named_self.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/global_variable/implicit_conversion.carbon b/explorer/testdata/global_variable/implicit_conversion.carbon
index b09cbcb41db0..32290635d803 100644
--- a/explorer/testdata/global_variable/implicit_conversion.carbon
+++ b/explorer/testdata/global_variable/implicit_conversion.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 5
 
 package ExplorerTest api;
diff --git a/explorer/testdata/global_variable/init_and_read.carbon b/explorer/testdata/global_variable/init_and_read.carbon
index 931886db35cb..9ca9586f8c6a 100644
--- a/explorer/testdata/global_variable/init_and_read.carbon
+++ b/explorer/testdata/global_variable/init_and_read.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/global_variable/init_from_function.carbon b/explorer/testdata/global_variable/init_from_function.carbon
index 36f95791680b..2abeb05ebdea 100644
--- a/explorer/testdata/global_variable/init_from_function.carbon
+++ b/explorer/testdata/global_variable/init_from_function.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/global_variable/init_order.carbon b/explorer/testdata/global_variable/init_order.carbon
index 5b2caf134b43..fa071548c2d4 100644
--- a/explorer/testdata/global_variable/init_order.carbon
+++ b/explorer/testdata/global_variable/init_order.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/global_variable/shadowing.carbon b/explorer/testdata/global_variable/shadowing.carbon
index a64c592fd30d..8ae040b03a5f 100644
--- a/explorer/testdata/global_variable/shadowing.carbon
+++ b/explorer/testdata/global_variable/shadowing.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/global_variable/write.carbon b/explorer/testdata/global_variable/write.carbon
index 6f53ff06365b..4866950d7037 100644
--- a/explorer/testdata/global_variable/write.carbon
+++ b/explorer/testdata/global_variable/write.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/global_variable/write_from_function.carbon b/explorer/testdata/global_variable/write_from_function.carbon
index a15d3213a582..d1cec5bb5220 100644
--- a/explorer/testdata/global_variable/write_from_function.carbon
+++ b/explorer/testdata/global_variable/write_from_function.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/if_else/convert_condition.carbon b/explorer/testdata/if_else/convert_condition.carbon
index 58a696cbffd6..54e40c9b5a25 100644
--- a/explorer/testdata/if_else/convert_condition.carbon
+++ b/explorer/testdata/if_else/convert_condition.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 1
 
 package ExplorerTest api;
diff --git a/explorer/testdata/if_else/if_else.carbon b/explorer/testdata/if_else/if_else.carbon
index 3cfef84c9db9..8c6f1d1e2880 100644
--- a/explorer/testdata/if_else/if_else.carbon
+++ b/explorer/testdata/if_else/if_else.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/if_else/if_else_if.carbon b/explorer/testdata/if_else/if_else_if.carbon
index 9ca07822880b..35520e1124db 100644
--- a/explorer/testdata/if_else/if_else_if.carbon
+++ b/explorer/testdata/if_else/if_else_if.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/if_else/if_else_if_else.carbon b/explorer/testdata/if_else/if_else_if_else.carbon
index 8886dbc4a0b1..2697a9c9641f 100644
--- a/explorer/testdata/if_else/if_else_if_else.carbon
+++ b/explorer/testdata/if_else/if_else_if_else.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/if_else/if_false.carbon b/explorer/testdata/if_else/if_false.carbon
index 404c908dae25..a78617067e2c 100644
--- a/explorer/testdata/if_else/if_false.carbon
+++ b/explorer/testdata/if_else/if_false.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/if_else/if_nesting.carbon b/explorer/testdata/if_else/if_nesting.carbon
index c4e3dfc06859..09c7c5710b42 100644
--- a/explorer/testdata/if_else/if_nesting.carbon
+++ b/explorer/testdata/if_else/if_nesting.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/if_else/if_true.carbon b/explorer/testdata/if_else/if_true.carbon
index 40a557de3f2c..738d35240f0c 100644
--- a/explorer/testdata/if_else/if_true.carbon
+++ b/explorer/testdata/if_else/if_true.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/if_expression/convert_condition.carbon b/explorer/testdata/if_expression/convert_condition.carbon
index f67084405dd0..488ea1825ed5 100644
--- a/explorer/testdata/if_expression/convert_condition.carbon
+++ b/explorer/testdata/if_expression/convert_condition.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 1
 
 package ExplorerTest api;
diff --git a/explorer/testdata/if_expression/if_then_else.carbon b/explorer/testdata/if_expression/if_then_else.carbon
index 2645c015a194..8b6d103543e9 100644
--- a/explorer/testdata/if_expression/if_then_else.carbon
+++ b/explorer/testdata/if_expression/if_then_else.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 12
 
 package ExplorerTest api;
diff --git a/explorer/testdata/impl/deducible_parameter.carbon b/explorer/testdata/impl/deducible_parameter.carbon
index 13fb07e59623..31fdcf44d9b5 100644
--- a/explorer/testdata/impl/deducible_parameter.carbon
+++ b/explorer/testdata/impl/deducible_parameter.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 1
 
 package ExplorerTest api;
diff --git a/explorer/testdata/impl/fail_ambiguous_impl.carbon b/explorer/testdata/impl/fail_ambiguous_impl.carbon
index 7f88f375ee07..18008961118c 100644
--- a/explorer/testdata/impl/fail_ambiguous_impl.carbon
+++ b/explorer/testdata/impl/fail_ambiguous_impl.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 
 package ExplorerTest api;
diff --git a/explorer/testdata/impl/fail_ambiguous_impl_generic.carbon b/explorer/testdata/impl/fail_ambiguous_impl_generic.carbon
index e465ea8397a2..367161227d26 100644
--- a/explorer/testdata/impl/fail_ambiguous_impl_generic.carbon
+++ b/explorer/testdata/impl/fail_ambiguous_impl_generic.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/impl/fail_bad_member_kind.carbon b/explorer/testdata/impl/fail_bad_member_kind.carbon
index c30abca90cb9..44672cfa1128 100644
--- a/explorer/testdata/impl/fail_bad_member_kind.carbon
+++ b/explorer/testdata/impl/fail_bad_member_kind.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/impl/fail_impl_as.carbon b/explorer/testdata/impl/fail_impl_as.carbon
index 6d5f0695917a..87aead878dba 100644
--- a/explorer/testdata/impl/fail_impl_as.carbon
+++ b/explorer/testdata/impl/fail_impl_as.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/impl/fail_impl_as_non_interface.carbon b/explorer/testdata/impl/fail_impl_as_non_interface.carbon
index 059fb245f3b0..e7ceaba68323 100644
--- a/explorer/testdata/impl/fail_impl_as_non_interface.carbon
+++ b/explorer/testdata/impl/fail_impl_as_non_interface.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/impl/fail_impl_as_not_constraint.carbon b/explorer/testdata/impl/fail_impl_as_not_constraint.carbon
index 546ecf185701..2ae73af4fd21 100644
--- a/explorer/testdata/impl/fail_impl_as_not_constraint.carbon
+++ b/explorer/testdata/impl/fail_impl_as_not_constraint.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/impl/fail_impl_as_parameterized.carbon b/explorer/testdata/impl/fail_impl_as_parameterized.carbon
index eb5307974b6c..90906b675b27 100644
--- a/explorer/testdata/impl/fail_impl_as_parameterized.carbon
+++ b/explorer/testdata/impl/fail_impl_as_parameterized.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/impl/fail_nondeducible_parameter.carbon b/explorer/testdata/impl/fail_nondeducible_parameter.carbon
index f0e9ce9e6ff5..9fbb0132e3e7 100644
--- a/explorer/testdata/impl/fail_nondeducible_parameter.carbon
+++ b/explorer/testdata/impl/fail_nondeducible_parameter.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/impl/fail_param_interface_in_impl.carbon b/explorer/testdata/impl/fail_param_interface_in_impl.carbon
index 864ad108e9d1..a7692b1e9212 100644
--- a/explorer/testdata/impl/fail_param_interface_in_impl.carbon
+++ b/explorer/testdata/impl/fail_param_interface_in_impl.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/impl/fail_unambiguous_impl_generic.carbon b/explorer/testdata/impl/fail_unambiguous_impl_generic.carbon
index 30bf99a8dd88..4273801c8f4f 100644
--- a/explorer/testdata/impl/fail_unambiguous_impl_generic.carbon
+++ b/explorer/testdata/impl/fail_unambiguous_impl_generic.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/impl/fail_unmet_impl_constraint.carbon b/explorer/testdata/impl/fail_unmet_impl_constraint.carbon
index a3f1b379222d..8c746bbebdfa 100644
--- a/explorer/testdata/impl/fail_unmet_impl_constraint.carbon
+++ b/explorer/testdata/impl/fail_unmet_impl_constraint.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/impl/generic_method_impl.carbon b/explorer/testdata/impl/generic_method_impl.carbon
index c93897d92a42..7ce19caf6219 100644
--- a/explorer/testdata/impl/generic_method_impl.carbon
+++ b/explorer/testdata/impl/generic_method_impl.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 3
 
 package ExplorerTest api;
diff --git a/explorer/testdata/impl/impl_constraint.carbon b/explorer/testdata/impl/impl_constraint.carbon
index c12f869a1536..b7d1952d8df7 100644
--- a/explorer/testdata/impl/impl_constraint.carbon
+++ b/explorer/testdata/impl/impl_constraint.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 1234
 
 package ExplorerTest api;
diff --git a/explorer/testdata/impl/impl_in_generic_class.carbon b/explorer/testdata/impl/impl_in_generic_class.carbon
index 24726bb480e1..255477eceddb 100644
--- a/explorer/testdata/impl/impl_in_generic_class.carbon
+++ b/explorer/testdata/impl/impl_in_generic_class.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 1133
 
 package ExplorerTest api;
diff --git a/explorer/testdata/impl/param_impl.carbon b/explorer/testdata/impl/param_impl.carbon
index af1b9077f1ad..f804e5ebcd6d 100644
--- a/explorer/testdata/impl/param_impl.carbon
+++ b/explorer/testdata/impl/param_impl.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/impl/param_impl2.carbon b/explorer/testdata/impl/param_impl2.carbon
index a5c51dd6f686..8444bc0836cf 100644
--- a/explorer/testdata/impl/param_impl2.carbon
+++ b/explorer/testdata/impl/param_impl2.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/impl/param_impl_with_self.carbon b/explorer/testdata/impl/param_impl_with_self.carbon
index 6d3cb3968e35..62804086c343 100644
--- a/explorer/testdata/impl/param_impl_with_self.carbon
+++ b/explorer/testdata/impl/param_impl_with_self.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/impl/param_interface_in_impl.carbon b/explorer/testdata/impl/param_interface_in_impl.carbon
index 1845976cf91f..f81cd9a59cfe 100644
--- a/explorer/testdata/impl/param_interface_in_impl.carbon
+++ b/explorer/testdata/impl/param_interface_in_impl.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/import/fail_order.carbon b/explorer/testdata/import/fail_order.carbon
index 888b2990c0f7..42126d028213 100644
--- a/explorer/testdata/import/fail_order.carbon
+++ b/explorer/testdata/import/fail_order.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/import/fail_nonexistent_library.carbon b/explorer/testdata/import/nonexistent_library.carbon
similarity index 71%
rename from explorer/testdata/import/fail_nonexistent_library.carbon
rename to explorer/testdata/import/nonexistent_library.carbon
index 9fa8767e9a34..beb390f3292d 100644
--- a/explorer/testdata/import/fail_nonexistent_library.carbon
+++ b/explorer/testdata/import/nonexistent_library.carbon
@@ -4,9 +4,9 @@
 //
 // TODO: This SHOULD fail but doesn't presently.
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/import/fail_nonexistent_package.carbon b/explorer/testdata/import/nonexistent_package.carbon
similarity index 72%
rename from explorer/testdata/import/fail_nonexistent_package.carbon
rename to explorer/testdata/import/nonexistent_package.carbon
index fc41d610b436..afd53e6a9ea3 100644
--- a/explorer/testdata/import/fail_nonexistent_package.carbon
+++ b/explorer/testdata/import/nonexistent_package.carbon
@@ -4,9 +4,9 @@
 //
 // TODO: This SHOULD fail but doesn't presently.
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/interface/assoc_constant_constraints_in_scope.carbon b/explorer/testdata/interface/assoc_constant_constraints_in_scope.carbon
index e76c40ec3c08..6a395372c0eb 100644
--- a/explorer/testdata/interface/assoc_constant_constraints_in_scope.carbon
+++ b/explorer/testdata/interface/assoc_constant_constraints_in_scope.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 5
 
 package ExplorerTest api;
diff --git a/explorer/testdata/interface/class_function.carbon b/explorer/testdata/interface/class_function.carbon
index 09d87492f98e..23f1192624f4 100644
--- a/explorer/testdata/interface/class_function.carbon
+++ b/explorer/testdata/interface/class_function.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/interface/constrained_parameter.carbon b/explorer/testdata/interface/constrained_parameter.carbon
index 3f4875d326b2..97c177365346 100644
--- a/explorer/testdata/interface/constrained_parameter.carbon
+++ b/explorer/testdata/interface/constrained_parameter.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/interface/extends.carbon b/explorer/testdata/interface/extends.carbon
index 4adb48f8c994..c8eb4129a2bd 100644
--- a/explorer/testdata/interface/extends.carbon
+++ b/explorer/testdata/interface/extends.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: Carrot.G
 // CHECK:STDOUT: result: 5
 
diff --git a/explorer/testdata/interface/external_impl_point_vector.carbon b/explorer/testdata/interface/external_impl_point_vector.carbon
index 775b4f068589..d2da1e11aadc 100644
--- a/explorer/testdata/interface/external_impl_point_vector.carbon
+++ b/explorer/testdata/interface/external_impl_point_vector.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/interface/external_impl_use_self.carbon b/explorer/testdata/interface/external_impl_use_self.carbon
index 366ed49891ac..289d7337491f 100644
--- a/explorer/testdata/interface/external_impl_use_self.carbon
+++ b/explorer/testdata/interface/external_impl_use_self.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/interface/fail_bad_member_kind.carbon b/explorer/testdata/interface/fail_bad_member_kind.carbon
index 14181240008c..395d41cab456 100644
--- a/explorer/testdata/interface/fail_bad_member_kind.carbon
+++ b/explorer/testdata/interface/fail_bad_member_kind.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/interface/fail_extends_not_constraint.carbon b/explorer/testdata/interface/fail_extends_not_constraint.carbon
index 67e624d6a2cb..f3b5aa45ae4d 100644
--- a/explorer/testdata/interface/fail_extends_not_constraint.carbon
+++ b/explorer/testdata/interface/fail_extends_not_constraint.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/interface/fail_external_impl_omit_self.carbon b/explorer/testdata/interface/fail_external_impl_omit_self.carbon
index e0a3d0bb3b2c..0797320148d6 100644
--- a/explorer/testdata/interface/fail_external_impl_omit_self.carbon
+++ b/explorer/testdata/interface/fail_external_impl_omit_self.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/interface/fail_external_impl_self.carbon b/explorer/testdata/interface/fail_external_impl_self.carbon
index 05f073f43ea0..e06bdff68774 100644
--- a/explorer/testdata/interface/fail_external_impl_self.carbon
+++ b/explorer/testdata/interface/fail_external_impl_self.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/interface/fail_impl_as_not_constraint.carbon b/explorer/testdata/interface/fail_impl_as_not_constraint.carbon
index c7e9f49414a5..e4b5980b9670 100644
--- a/explorer/testdata/interface/fail_impl_as_not_constraint.carbon
+++ b/explorer/testdata/interface/fail_impl_as_not_constraint.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/interface/fail_impl_as_not_type.carbon b/explorer/testdata/interface/fail_impl_as_not_type.carbon
index 3047b1e44bbd..cbc6f3e7c259 100644
--- a/explorer/testdata/interface/fail_impl_as_not_type.carbon
+++ b/explorer/testdata/interface/fail_impl_as_not_type.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/interface/fail_impl_bad_member.carbon b/explorer/testdata/interface/fail_impl_bad_member.carbon
index 40e22a81105e..ed0c5fa47e56 100644
--- a/explorer/testdata/interface/fail_impl_bad_member.carbon
+++ b/explorer/testdata/interface/fail_impl_bad_member.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/interface/fail_impl_missing_member.carbon b/explorer/testdata/interface/fail_impl_missing_member.carbon
index b9d0e01ca98d..7e843e089ba9 100644
--- a/explorer/testdata/interface/fail_impl_missing_member.carbon
+++ b/explorer/testdata/interface/fail_impl_missing_member.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/interface/fail_impl_not_type.carbon b/explorer/testdata/interface/fail_impl_not_type.carbon
index bbf5779fcab6..a7c022942a52 100644
--- a/explorer/testdata/interface/fail_impl_not_type.carbon
+++ b/explorer/testdata/interface/fail_impl_not_type.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/interface/fail_interface_missing_member.carbon b/explorer/testdata/interface/fail_interface_missing_member.carbon
index 37d0e618bec6..b998ea533ce9 100644
--- a/explorer/testdata/interface/fail_interface_missing_member.carbon
+++ b/explorer/testdata/interface/fail_interface_missing_member.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/interface/fail_member_lookup_in_definition.carbon b/explorer/testdata/interface/fail_member_lookup_in_definition.carbon
index cf080f2ed9ad..dbf274540aa5 100644
--- a/explorer/testdata/interface/fail_member_lookup_in_definition.carbon
+++ b/explorer/testdata/interface/fail_member_lookup_in_definition.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s 2>&1 | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s 2>&1 | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/interface/fail_no_impl.carbon b/explorer/testdata/interface/fail_no_impl.carbon
index 21ff0f114ab5..cf53b3375fff 100644
--- a/explorer/testdata/interface/fail_no_impl.carbon
+++ b/explorer/testdata/interface/fail_no_impl.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/interface/fail_self_lookup_in_definition.carbon b/explorer/testdata/interface/fail_self_lookup_in_definition.carbon
index 45e18e3969fc..1d7cbfd1e9ee 100644
--- a/explorer/testdata/interface/fail_self_lookup_in_definition.carbon
+++ b/explorer/testdata/interface/fail_self_lookup_in_definition.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s 2>&1 | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s 2>&1 | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/interface/fail_use_symbolic_member.carbon b/explorer/testdata/interface/fail_use_symbolic_member.carbon
index 82c0de478f4b..71ab6e0d69c5 100644
--- a/explorer/testdata/interface/fail_use_symbolic_member.carbon
+++ b/explorer/testdata/interface/fail_use_symbolic_member.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/interface/generic_call_generic.carbon b/explorer/testdata/interface/generic_call_generic.carbon
index 18765a822332..42ead9706f82 100644
--- a/explorer/testdata/interface/generic_call_generic.carbon
+++ b/explorer/testdata/interface/generic_call_generic.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/interface/generic_with_two_params.carbon b/explorer/testdata/interface/generic_with_two_params.carbon
index 8b8cd48a8de3..7348ba55e5de 100644
--- a/explorer/testdata/interface/generic_with_two_params.carbon
+++ b/explorer/testdata/interface/generic_with_two_params.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/interface/impl_as.carbon b/explorer/testdata/interface/impl_as.carbon
index 4a0c59591e07..781a1e133695 100644
--- a/explorer/testdata/interface/impl_as.carbon
+++ b/explorer/testdata/interface/impl_as.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: Carrot.G
 // CHECK:STDOUT: result: 5
 
diff --git a/explorer/testdata/interface/impl_as_not_self.carbon b/explorer/testdata/interface/impl_as_not_self.carbon
index 4d51fe1bace6..d1c97506b589 100644
--- a/explorer/testdata/interface/impl_as_not_self.carbon
+++ b/explorer/testdata/interface/impl_as_not_self.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 5
 
 package ExplorerTest api;
diff --git a/explorer/testdata/interface/impl_self_interface_parameter.carbon b/explorer/testdata/interface/impl_self_interface_parameter.carbon
index 6b7f08daed59..4693808a4a85 100644
--- a/explorer/testdata/interface/impl_self_interface_parameter.carbon
+++ b/explorer/testdata/interface/impl_self_interface_parameter.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/interface/omit_self.carbon b/explorer/testdata/interface/omit_self.carbon
index 9a86bebaad10..68b643178536 100644
--- a/explorer/testdata/interface/omit_self.carbon
+++ b/explorer/testdata/interface/omit_self.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/interface/param_with_dependent_type.carbon b/explorer/testdata/interface/param_with_dependent_type.carbon
index b4e25be7bfae..a4cc57034ee6 100644
--- a/explorer/testdata/interface/param_with_dependent_type.carbon
+++ b/explorer/testdata/interface/param_with_dependent_type.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 42
 
 package ExplorerTest api;
diff --git a/explorer/testdata/interface/parameterized.carbon b/explorer/testdata/interface/parameterized.carbon
index 7ed5d12f2ef9..10aadcc4f5e2 100644
--- a/explorer/testdata/interface/parameterized.carbon
+++ b/explorer/testdata/interface/parameterized.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/interface/tuple_vector_add_scale.carbon b/explorer/testdata/interface/tuple_vector_add_scale.carbon
index 40b7960b00f4..f2e87211d334 100644
--- a/explorer/testdata/interface/tuple_vector_add_scale.carbon
+++ b/explorer/testdata/interface/tuple_vector_add_scale.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/interface/vector_point_add_scale.carbon b/explorer/testdata/interface/vector_point_add_scale.carbon
index bb1a8da5483d..3b6f48fd1bed 100644
--- a/explorer/testdata/interface/vector_point_add_scale.carbon
+++ b/explorer/testdata/interface/vector_point_add_scale.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/interface/with_self.carbon b/explorer/testdata/interface/with_self.carbon
index 7b2b595f7414..56331c6855fc 100644
--- a/explorer/testdata/interface/with_self.carbon
+++ b/explorer/testdata/interface/with_self.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/let/fail_function_args.carbon b/explorer/testdata/let/fail_function_args.carbon
index 0c8aa69f89e6..fedc6c179d75 100644
--- a/explorer/testdata/let/fail_function_args.carbon
+++ b/explorer/testdata/let/fail_function_args.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/let/fail_global_assign.carbon b/explorer/testdata/let/fail_global_assign.carbon
index fb46c145ca32..b5fa4a038473 100644
--- a/explorer/testdata/let/fail_global_assign.carbon
+++ b/explorer/testdata/let/fail_global_assign.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/let/fail_global_named_self.carbon b/explorer/testdata/let/fail_global_named_self.carbon
index c27ae37714d3..66fbcf185678 100644
--- a/explorer/testdata/let/fail_global_named_self.carbon
+++ b/explorer/testdata/let/fail_global_named_self.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/let/fail_local_assign.carbon b/explorer/testdata/let/fail_local_assign.carbon
index 6d5bcbd48a4b..36a565ae9b18 100644
--- a/explorer/testdata/let/fail_local_assign.carbon
+++ b/explorer/testdata/let/fail_local_assign.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/let/fail_local_named_self.carbon b/explorer/testdata/let/fail_local_named_self.carbon
index 75e9e33d8060..63ec9f5d5f2e 100644
--- a/explorer/testdata/let/fail_local_named_self.carbon
+++ b/explorer/testdata/let/fail_local_named_self.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/let/fail_match_choice.carbon b/explorer/testdata/let/fail_match_choice.carbon
index 5c44957fa249..7bb8a61209f9 100644
--- a/explorer/testdata/let/fail_match_choice.carbon
+++ b/explorer/testdata/let/fail_match_choice.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/let/fail_method_args.carbon b/explorer/testdata/let/fail_method_args.carbon
index 6fe6738c04c5..8afed02c3e80 100644
--- a/explorer/testdata/let/fail_method_args.carbon
+++ b/explorer/testdata/let/fail_method_args.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/let/fail_tuple_pattern_let_context.carbon b/explorer/testdata/let/fail_tuple_pattern_let_context.carbon
index 4d0785bad9fe..56a79ce2924e 100644
--- a/explorer/testdata/let/fail_tuple_pattern_let_context.carbon
+++ b/explorer/testdata/let/fail_tuple_pattern_let_context.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/let/fail_tuple_pattern_let_context_nested.carbon b/explorer/testdata/let/fail_tuple_pattern_let_context_nested.carbon
index fe17fa66931e..33ae08c0e026 100644
--- a/explorer/testdata/let/fail_tuple_pattern_let_context_nested.carbon
+++ b/explorer/testdata/let/fail_tuple_pattern_let_context_nested.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/let/fail_tuple_pattern_let_in_var.carbon b/explorer/testdata/let/fail_tuple_pattern_let_in_var.carbon
index 698d7b0505e0..93f4012986d5 100644
--- a/explorer/testdata/let/fail_tuple_pattern_let_in_var.carbon
+++ b/explorer/testdata/let/fail_tuple_pattern_let_in_var.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/let/implicit_conversion.carbon b/explorer/testdata/let/implicit_conversion.carbon
index 5b3577db1efe..66530763e0ef 100644
--- a/explorer/testdata/let/implicit_conversion.carbon
+++ b/explorer/testdata/let/implicit_conversion.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 3
 
 package ExplorerTest api;
diff --git a/explorer/testdata/let/implicit_conversion_choice.carbon b/explorer/testdata/let/implicit_conversion_choice.carbon
index 75113db4be58..1f902a4e7da1 100644
--- a/explorer/testdata/let/implicit_conversion_choice.carbon
+++ b/explorer/testdata/let/implicit_conversion_choice.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 3
 
 package ExplorerTest api;
diff --git a/explorer/testdata/let/nested_tuple_pattern.carbon b/explorer/testdata/let/nested_tuple_pattern.carbon
index 69da4420b01f..f1df8d7c3a87 100644
--- a/explorer/testdata/let/nested_tuple_pattern.carbon
+++ b/explorer/testdata/let/nested_tuple_pattern.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/linked_list/linked_list.carbon b/explorer/testdata/linked_list/linked_list.carbon
index e338cc6e2d16..4f67ad66bf6b 100644
--- a/explorer/testdata/linked_list/linked_list.carbon
+++ b/explorer/testdata/linked_list/linked_list.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: 1
 // CHECK:STDOUT: 2
 // CHECK:STDOUT: 3
diff --git a/explorer/testdata/match/any_int.carbon b/explorer/testdata/match/any_int.carbon
index 12101f3bca4d..416de606678f 100644
--- a/explorer/testdata/match/any_int.carbon
+++ b/explorer/testdata/match/any_int.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/match/convert.carbon b/explorer/testdata/match/convert.carbon
index 6ceb47eed715..02a64896defe 100644
--- a/explorer/testdata/match/convert.carbon
+++ b/explorer/testdata/match/convert.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/match/exhaustive.carbon b/explorer/testdata/match/exhaustive.carbon
index e8cb98e54873..c9d037c305da 100644
--- a/explorer/testdata/match/exhaustive.carbon
+++ b/explorer/testdata/match/exhaustive.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 3
 
 package ExplorerTest api;
diff --git a/explorer/testdata/match/exhaustive_bool.carbon b/explorer/testdata/match/exhaustive_bool.carbon
index 1ed547166eb3..82e939cb9bfc 100644
--- a/explorer/testdata/match/exhaustive_bool.carbon
+++ b/explorer/testdata/match/exhaustive_bool.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 2
 
 package ExplorerTest api;
diff --git a/explorer/testdata/match/exhaustive_exponential_8x.carbon b/explorer/testdata/match/exhaustive_exponential_8x.carbon
index a0c8fc33dd23..8ec84af93619 100644
--- a/explorer/testdata/match/exhaustive_exponential_8x.carbon
+++ b/explorer/testdata/match/exhaustive_exponential_8x.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/match/exhaustive_exponential_series_t.carbon b/explorer/testdata/match/exhaustive_exponential_series_t.carbon
index 166d8d88efc3..f35a107799c4 100644
--- a/explorer/testdata/match/exhaustive_exponential_series_t.carbon
+++ b/explorer/testdata/match/exhaustive_exponential_series_t.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/match/fail_exhaustive_exponential_9x.carbon b/explorer/testdata/match/fail_exhaustive_exponential_9x.carbon
index 46836bd2b932..ff2c8565a332 100644
--- a/explorer/testdata/match/fail_exhaustive_exponential_9x.carbon
+++ b/explorer/testdata/match/fail_exhaustive_exponential_9x.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/match/fail_exhaustive_exponential_series_t.carbon b/explorer/testdata/match/fail_exhaustive_exponential_series_t.carbon
index 8bf6aac6257d..bda01d78c4b8 100644
--- a/explorer/testdata/match/fail_exhaustive_exponential_series_t.carbon
+++ b/explorer/testdata/match/fail_exhaustive_exponential_series_t.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/match/fail_exhaustive_int.carbon b/explorer/testdata/match/fail_exhaustive_int.carbon
index 232db172d0b3..b028ed98acc5 100644
--- a/explorer/testdata/match/fail_exhaustive_int.carbon
+++ b/explorer/testdata/match/fail_exhaustive_int.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/match/fail_not_alternative.carbon b/explorer/testdata/match/fail_not_alternative.carbon
index bb3e6ddce51e..f7b1f6319aa1 100644
--- a/explorer/testdata/match/fail_not_alternative.carbon
+++ b/explorer/testdata/match/fail_not_alternative.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/match/fail_not_exhaustive.carbon b/explorer/testdata/match/fail_not_exhaustive.carbon
index 0dc9adbc4e27..a3e419c475a1 100644
--- a/explorer/testdata/match/fail_not_exhaustive.carbon
+++ b/explorer/testdata/match/fail_not_exhaustive.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/match/fail_not_reachable.carbon b/explorer/testdata/match/fail_not_reachable.carbon
index 35440d15dcbd..c285a21e543e 100644
--- a/explorer/testdata/match/fail_not_reachable.carbon
+++ b/explorer/testdata/match/fail_not_reachable.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/match/fail_not_reachable_default.carbon b/explorer/testdata/match/fail_not_reachable_default.carbon
index fb64bb8591f8..002d5a488048 100644
--- a/explorer/testdata/match/fail_not_reachable_default.carbon
+++ b/explorer/testdata/match/fail_not_reachable_default.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/match/fail_pattern_type_mismatch.carbon b/explorer/testdata/match/fail_pattern_type_mismatch.carbon
index 336a102c6d26..8fdfa3938b48 100644
--- a/explorer/testdata/match/fail_pattern_type_mismatch.carbon
+++ b/explorer/testdata/match/fail_pattern_type_mismatch.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/match/fail_redundant_int.carbon b/explorer/testdata/match/fail_redundant_int.carbon
index 3cfc320d615d..83ffcf0d6c59 100644
--- a/explorer/testdata/match/fail_redundant_int.carbon
+++ b/explorer/testdata/match/fail_redundant_int.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/match/int.carbon b/explorer/testdata/match/int.carbon
index 2f541469a55a..54cc7e5eba73 100644
--- a/explorer/testdata/match/int.carbon
+++ b/explorer/testdata/match/int.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/match/int_default.carbon b/explorer/testdata/match/int_default.carbon
index 95052f312947..0024c14b92df 100644
--- a/explorer/testdata/match/int_default.carbon
+++ b/explorer/testdata/match/int_default.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/match/no_match.carbon b/explorer/testdata/match/no_match.carbon
index a8a8ded5207c..456306e618e2 100644
--- a/explorer/testdata/match/no_match.carbon
+++ b/explorer/testdata/match/no_match.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/match/placeholder.carbon b/explorer/testdata/match/placeholder.carbon
index cfb13f9c7e97..b50663c9f11f 100644
--- a/explorer/testdata/match/placeholder.carbon
+++ b/explorer/testdata/match/placeholder.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/member_access/convert_lhs_class.carbon b/explorer/testdata/member_access/convert_lhs_class.carbon
index c428c1e4a653..0115bf8541c9 100644
--- a/explorer/testdata/member_access/convert_lhs_class.carbon
+++ b/explorer/testdata/member_access/convert_lhs_class.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 3
 
 package Foo api;
diff --git a/explorer/testdata/member_access/convert_lhs_interface.carbon b/explorer/testdata/member_access/convert_lhs_interface.carbon
index 6503a3fc9827..19ba30ff648b 100644
--- a/explorer/testdata/member_access/convert_lhs_interface.carbon
+++ b/explorer/testdata/member_access/convert_lhs_interface.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 3
 
 package Foo api;
diff --git a/explorer/testdata/member_access/evaluate_type_before_dot.carbon b/explorer/testdata/member_access/evaluate_type_before_dot.carbon
index 4ea7a931bc71..c7769c4eb93f 100644
--- a/explorer/testdata/member_access/evaluate_type_before_dot.carbon
+++ b/explorer/testdata/member_access/evaluate_type_before_dot.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: Struct OK
 // CHECK:STDOUT: Choice OK
 // CHECK:STDOUT: Class OK
diff --git a/explorer/testdata/member_access/fail_qualified_non_member.carbon b/explorer/testdata/member_access/fail_qualified_non_member.carbon
index cd03fcb05f93..e68c4324be4f 100644
--- a/explorer/testdata/member_access/fail_qualified_non_member.carbon
+++ b/explorer/testdata/member_access/fail_qualified_non_member.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package Foo api;
 fn F[me: i32]() {}
diff --git a/explorer/testdata/member_access/fail_vacuous_access.carbon b/explorer/testdata/member_access/fail_vacuous_access.carbon
index 26e9f51975ee..a6eb74d90114 100644
--- a/explorer/testdata/member_access/fail_vacuous_access.carbon
+++ b/explorer/testdata/member_access/fail_vacuous_access.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package Foo api;
 interface A { fn F() -> i32; }
diff --git a/explorer/testdata/member_access/fail_vacuous_access_via_type_param.carbon b/explorer/testdata/member_access/fail_vacuous_access_via_type_param.carbon
index 359f4f523f7a..3dfc8014cdc0 100644
--- a/explorer/testdata/member_access/fail_vacuous_access_via_type_param.carbon
+++ b/explorer/testdata/member_access/fail_vacuous_access_via_type_param.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package Foo api;
 interface A { fn F() -> i32; }
diff --git a/explorer/testdata/member_access/nearly_vacuous_access_with_impl_lookup.carbon b/explorer/testdata/member_access/nearly_vacuous_access_with_impl_lookup.carbon
index 72f0dd6cb2b5..a6b2411db912 100644
--- a/explorer/testdata/member_access/nearly_vacuous_access_with_impl_lookup.carbon
+++ b/explorer/testdata/member_access/nearly_vacuous_access_with_impl_lookup.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 1
 
 package Foo api;
diff --git a/explorer/testdata/member_access/nearly_vacuous_access_with_instance_binding.carbon b/explorer/testdata/member_access/nearly_vacuous_access_with_instance_binding.carbon
index 4d4376a507db..d852d4a805d4 100644
--- a/explorer/testdata/member_access/nearly_vacuous_access_with_instance_binding.carbon
+++ b/explorer/testdata/member_access/nearly_vacuous_access_with_instance_binding.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 1
 
 package Foo api;
diff --git a/explorer/testdata/member_access/param_qualified_interface_member.carbon b/explorer/testdata/member_access/param_qualified_interface_member.carbon
index 87042132f132..211fdcfadf11 100644
--- a/explorer/testdata/member_access/param_qualified_interface_member.carbon
+++ b/explorer/testdata/member_access/param_qualified_interface_member.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 3
 
 package Foo api;
diff --git a/explorer/testdata/member_access/qualified_class_member.carbon b/explorer/testdata/member_access/qualified_class_member.carbon
index ebf6413c2ebb..f892b169b7ca 100644
--- a/explorer/testdata/member_access/qualified_class_member.carbon
+++ b/explorer/testdata/member_access/qualified_class_member.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 3
 
 package Foo api;
diff --git a/explorer/testdata/member_access/qualified_constraint_member.carbon b/explorer/testdata/member_access/qualified_constraint_member.carbon
index e1592346f96f..86eaf95d485a 100644
--- a/explorer/testdata/member_access/qualified_constraint_member.carbon
+++ b/explorer/testdata/member_access/qualified_constraint_member.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 12
 
 package Foo api;
diff --git a/explorer/testdata/member_access/qualified_interface_member.carbon b/explorer/testdata/member_access/qualified_interface_member.carbon
index 7067578d90e7..969a47d884c7 100644
--- a/explorer/testdata/member_access/qualified_interface_member.carbon
+++ b/explorer/testdata/member_access/qualified_interface_member.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 3
 
 package Foo api;
diff --git a/explorer/testdata/member_access/qualified_param_member.carbon b/explorer/testdata/member_access/qualified_param_member.carbon
index dc73a87b8285..a9d9ee0e1459 100644
--- a/explorer/testdata/member_access/qualified_param_member.carbon
+++ b/explorer/testdata/member_access/qualified_param_member.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 3
 
 package Foo api;
diff --git a/explorer/testdata/member_access/qualified_struct_member.carbon b/explorer/testdata/member_access/qualified_struct_member.carbon
index 48ef8b756678..0cdcfd4511f1 100644
--- a/explorer/testdata/member_access/qualified_struct_member.carbon
+++ b/explorer/testdata/member_access/qualified_struct_member.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 2
 
 package Foo api;
diff --git a/explorer/testdata/member_access/type_qualified_interface_member.carbon b/explorer/testdata/member_access/type_qualified_interface_member.carbon
index 1ff905a83416..60013f6e2b3f 100644
--- a/explorer/testdata/member_access/type_qualified_interface_member.carbon
+++ b/explorer/testdata/member_access/type_qualified_interface_member.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 42
 
 package Foo api;
diff --git a/explorer/testdata/mixin/fail_circular_mixing.carbon b/explorer/testdata/mixin/fail_circular_mixing.carbon
index 9a8d016e4a84..24d3f813fef0 100644
--- a/explorer/testdata/mixin/fail_circular_mixing.carbon
+++ b/explorer/testdata/mixin/fail_circular_mixing.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 package ExplorerTest api;
 
 __mixin M1 {
diff --git a/explorer/testdata/mixin/fail_field_member_name_clash.carbon b/explorer/testdata/mixin/fail_field_member_name_clash.carbon
index 4c3dbcb9902f..77beaece9f38 100644
--- a/explorer/testdata/mixin/fail_field_member_name_clash.carbon
+++ b/explorer/testdata/mixin/fail_field_member_name_clash.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/mixin/fail_method_member_name_clash.carbon b/explorer/testdata/mixin/fail_method_member_name_clash.carbon
index e63360347c7b..5692a64e104f 100644
--- a/explorer/testdata/mixin/fail_method_member_name_clash.carbon
+++ b/explorer/testdata/mixin/fail_method_member_name_clash.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/mixin/fail_mix_as_type_expr.carbon b/explorer/testdata/mixin/fail_mix_as_type_expr.carbon
index e6bb362b3427..da41dfb1e085 100644
--- a/explorer/testdata/mixin/fail_mix_as_type_expr.carbon
+++ b/explorer/testdata/mixin/fail_mix_as_type_expr.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/mixin/fail_mix_diamond_clash.carbon b/explorer/testdata/mixin/fail_mix_diamond_clash.carbon
index e3396b39a390..275346346e1a 100644
--- a/explorer/testdata/mixin/fail_mix_diamond_clash.carbon
+++ b/explorer/testdata/mixin/fail_mix_diamond_clash.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 package ExplorerTest api;
 
 __mixin M1 {
diff --git a/explorer/testdata/mixin/fail_mix_in_global.carbon b/explorer/testdata/mixin/fail_mix_in_global.carbon
index 393ecf32617b..9432a5953bbf 100644
--- a/explorer/testdata/mixin/fail_mix_in_global.carbon
+++ b/explorer/testdata/mixin/fail_mix_in_global.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/mixin/fail_mix_in_impl.carbon b/explorer/testdata/mixin/fail_mix_in_impl.carbon
index 04d1bd7f5d6c..cb1127c2b81c 100644
--- a/explorer/testdata/mixin/fail_mix_in_impl.carbon
+++ b/explorer/testdata/mixin/fail_mix_in_impl.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/mixin/fail_mix_members_clash.carbon b/explorer/testdata/mixin/fail_mix_members_clash.carbon
index ae442e7b8050..1f97215a9ada 100644
--- a/explorer/testdata/mixin/fail_mix_members_clash.carbon
+++ b/explorer/testdata/mixin/fail_mix_members_clash.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 package ExplorerTest api;
 
 __mixin M1 {
diff --git a/explorer/testdata/mixin/fail_recursive_mixing.carbon b/explorer/testdata/mixin/fail_recursive_mixing.carbon
index 91bffcc5168f..eb072593e743 100644
--- a/explorer/testdata/mixin/fail_recursive_mixing.carbon
+++ b/explorer/testdata/mixin/fail_recursive_mixing.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 package ExplorerTest api;
 
 __mixin M1 {
diff --git a/explorer/testdata/mixin/fail_self_substitution.carbon b/explorer/testdata/mixin/fail_self_substitution.carbon
index ee4e89481535..24100a871bdf 100644
--- a/explorer/testdata/mixin/fail_self_substitution.carbon
+++ b/explorer/testdata/mixin/fail_self_substitution.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/mixin/self_substitution.carbon b/explorer/testdata/mixin/self_substitution.carbon
index adf91b73bf38..e80b4e3a9035 100644
--- a/explorer/testdata/mixin/self_substitution.carbon
+++ b/explorer/testdata/mixin/self_substitution.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/mixin/simple_mix_in_mixin.carbon b/explorer/testdata/mixin/simple_mix_in_mixin.carbon
index a19051553ba6..6b2126fa649e 100644
--- a/explorer/testdata/mixin/simple_mix_in_mixin.carbon
+++ b/explorer/testdata/mixin/simple_mix_in_mixin.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/mixin/simple_reuse.carbon b/explorer/testdata/mixin/simple_reuse.carbon
index 2b4a69c39f70..cf2e981214a2 100644
--- a/explorer/testdata/mixin/simple_reuse.carbon
+++ b/explorer/testdata/mixin/simple_reuse.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/mixin/use_mixin_method_in_class_method.carbon b/explorer/testdata/mixin/use_mixin_method_in_class_method.carbon
index a791daf80e17..5693f4165946 100644
--- a/explorer/testdata/mixin/use_mixin_method_in_class_method.carbon
+++ b/explorer/testdata/mixin/use_mixin_method_in_class_method.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/name_lookup/class_fn_body_reorder.carbon b/explorer/testdata/name_lookup/class_fn_body_reorder.carbon
index 683900b47bf6..b4943e478a08 100644
--- a/explorer/testdata/name_lookup/class_fn_body_reorder.carbon
+++ b/explorer/testdata/name_lookup/class_fn_body_reorder.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 3
 
 package ExplorerTest api;
diff --git a/explorer/testdata/name_lookup/fail_block_duplicate.carbon b/explorer/testdata/name_lookup/fail_block_duplicate.carbon
index 80a2ec8ec5dc..b2ebe00d99a6 100644
--- a/explorer/testdata/name_lookup/fail_block_duplicate.carbon
+++ b/explorer/testdata/name_lookup/fail_block_duplicate.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/name_lookup/fail_choice_duplicate.carbon b/explorer/testdata/name_lookup/fail_choice_duplicate.carbon
index 51b25cb2db74..04c96afa53f9 100644
--- a/explorer/testdata/name_lookup/fail_choice_duplicate.carbon
+++ b/explorer/testdata/name_lookup/fail_choice_duplicate.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/name_lookup/fail_class_duplicate.carbon b/explorer/testdata/name_lookup/fail_class_duplicate.carbon
index 0f697b4c26b8..299648e075b8 100644
--- a/explorer/testdata/name_lookup/fail_class_duplicate.carbon
+++ b/explorer/testdata/name_lookup/fail_class_duplicate.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/name_lookup/fail_class_fn_use_before_declaration.carbon b/explorer/testdata/name_lookup/fail_class_fn_use_before_declaration.carbon
index 49af9fd89d14..44d559a2edee 100644
--- a/explorer/testdata/name_lookup/fail_class_fn_use_before_declaration.carbon
+++ b/explorer/testdata/name_lookup/fail_class_fn_use_before_declaration.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/name_lookup/fail_class_use_in_params.carbon b/explorer/testdata/name_lookup/fail_class_use_in_params.carbon
index b7394999c8b8..67efa56ae86d 100644
--- a/explorer/testdata/name_lookup/fail_class_use_in_params.carbon
+++ b/explorer/testdata/name_lookup/fail_class_use_in_params.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/name_lookup/fail_fn_use_in_param.carbon b/explorer/testdata/name_lookup/fail_fn_use_in_param.carbon
index f30eb434dfa0..8e61cb7928ef 100644
--- a/explorer/testdata/name_lookup/fail_fn_use_in_param.carbon
+++ b/explorer/testdata/name_lookup/fail_fn_use_in_param.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/name_lookup/fail_fn_use_in_return_type.carbon b/explorer/testdata/name_lookup/fail_fn_use_in_return_type.carbon
index 805ea30925d3..60ff9fa27dd6 100644
--- a/explorer/testdata/name_lookup/fail_fn_use_in_return_type.carbon
+++ b/explorer/testdata/name_lookup/fail_fn_use_in_return_type.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/name_lookup/fail_global_duplicate.carbon b/explorer/testdata/name_lookup/fail_global_duplicate.carbon
index 7ccb8abe6e11..c20af979eb26 100644
--- a/explorer/testdata/name_lookup/fail_global_duplicate.carbon
+++ b/explorer/testdata/name_lookup/fail_global_duplicate.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/name_lookup/fail_use_before_declare.carbon b/explorer/testdata/name_lookup/fail_use_before_declare.carbon
index 99cf706de9b9..24cab8e30f1d 100644
--- a/explorer/testdata/name_lookup/fail_use_before_declare.carbon
+++ b/explorer/testdata/name_lookup/fail_use_before_declare.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/name_lookup/fail_var_use_before_declaration.carbon b/explorer/testdata/name_lookup/fail_var_use_before_declaration.carbon
index f13f0a4f8660..3d2386cf5b89 100644
--- a/explorer/testdata/name_lookup/fail_var_use_before_declaration.carbon
+++ b/explorer/testdata/name_lookup/fail_var_use_before_declaration.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/name_lookup/global_shadow.carbon b/explorer/testdata/name_lookup/global_shadow.carbon
index 784438ac1a66..ca6a35f612b4 100644
--- a/explorer/testdata/name_lookup/global_shadow.carbon
+++ b/explorer/testdata/name_lookup/global_shadow.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/name_lookup/match_shadow.carbon b/explorer/testdata/name_lookup/match_shadow.carbon
index 6b28e6ed24e4..ea499ac1b79c 100644
--- a/explorer/testdata/name_lookup/match_shadow.carbon
+++ b/explorer/testdata/name_lookup/match_shadow.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 1
 
 package ExplorerTest api;
diff --git a/explorer/testdata/operators/add.carbon b/explorer/testdata/operators/add.carbon
index 319ec44989ae..1dcfe64c02d2 100644
--- a/explorer/testdata/operators/add.carbon
+++ b/explorer/testdata/operators/add.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 6
 
 package ExplorerTest api;
diff --git a/explorer/testdata/operators/add_builtin.carbon b/explorer/testdata/operators/add_builtin.carbon
index 11ea9bd277db..c3be7accc582 100644
--- a/explorer/testdata/operators/add_builtin.carbon
+++ b/explorer/testdata/operators/add_builtin.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: Interface: 5
 // CHECK:STDOUT: Op: 5
 // CHECK:STDOUT: result: 0
diff --git a/explorer/testdata/operators/bit_and.carbon b/explorer/testdata/operators/bit_and.carbon
index 799586ca38ef..c28e4ce27f41 100644
--- a/explorer/testdata/operators/bit_and.carbon
+++ b/explorer/testdata/operators/bit_and.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 1
 
 package ExplorerTest api;
diff --git a/explorer/testdata/operators/bit_complement.carbon b/explorer/testdata/operators/bit_complement.carbon
index 61ac5493ed67..27e830567cf8 100644
--- a/explorer/testdata/operators/bit_complement.carbon
+++ b/explorer/testdata/operators/bit_complement.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: -6
 
 package ExplorerTest api;
diff --git a/explorer/testdata/operators/bit_or.carbon b/explorer/testdata/operators/bit_or.carbon
index d9d27a4f80a7..ab28b2c19de6 100644
--- a/explorer/testdata/operators/bit_or.carbon
+++ b/explorer/testdata/operators/bit_or.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 5
 
 package ExplorerTest api;
diff --git a/explorer/testdata/operators/bit_xor.carbon b/explorer/testdata/operators/bit_xor.carbon
index d58fd484e678..bb082591296f 100644
--- a/explorer/testdata/operators/bit_xor.carbon
+++ b/explorer/testdata/operators/bit_xor.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 4
 
 package ExplorerTest api;
diff --git a/explorer/testdata/operators/bitwise.carbon b/explorer/testdata/operators/bitwise.carbon
index 601c78e56079..66919c708046 100644
--- a/explorer/testdata/operators/bitwise.carbon
+++ b/explorer/testdata/operators/bitwise.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/operators/div.carbon b/explorer/testdata/operators/div.carbon
index a14ded4a698f..2c0eb84d1976 100644
--- a/explorer/testdata/operators/div.carbon
+++ b/explorer/testdata/operators/div.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 2
 
 package ExplorerTest api;
diff --git a/explorer/testdata/operators/div_builtin.carbon b/explorer/testdata/operators/div_builtin.carbon
index 3b89e7c05183..e05e561eff91 100644
--- a/explorer/testdata/operators/div_builtin.carbon
+++ b/explorer/testdata/operators/div_builtin.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: Interface: 2
 // CHECK:STDOUT: Op: 2
 // CHECK:STDOUT: result: 0
diff --git a/explorer/testdata/operators/fail_no_add.carbon b/explorer/testdata/operators/fail_no_add.carbon
index 8bb70f07c3ee..9275d3f47352 100644
--- a/explorer/testdata/operators/fail_no_add.carbon
+++ b/explorer/testdata/operators/fail_no_add.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/operators/fail_no_mul.carbon b/explorer/testdata/operators/fail_no_mul.carbon
index 7fe93db59a98..db7a9cec8d33 100644
--- a/explorer/testdata/operators/fail_no_mul.carbon
+++ b/explorer/testdata/operators/fail_no_mul.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/operators/fail_no_negate.carbon b/explorer/testdata/operators/fail_no_negate.carbon
index 2327abe0b5db..503ef31e6621 100644
--- a/explorer/testdata/operators/fail_no_negate.carbon
+++ b/explorer/testdata/operators/fail_no_negate.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/operators/fail_no_sub.carbon b/explorer/testdata/operators/fail_no_sub.carbon
index 19136b840740..3ea414ac8500 100644
--- a/explorer/testdata/operators/fail_no_sub.carbon
+++ b/explorer/testdata/operators/fail_no_sub.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/operators/left_shift.carbon b/explorer/testdata/operators/left_shift.carbon
index a2d603e93590..992dd1138e6d 100644
--- a/explorer/testdata/operators/left_shift.carbon
+++ b/explorer/testdata/operators/left_shift.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 10
 
 package ExplorerTest api;
diff --git a/explorer/testdata/operators/mod.carbon b/explorer/testdata/operators/mod.carbon
index d0d2e0276691..05d038666667 100644
--- a/explorer/testdata/operators/mod.carbon
+++ b/explorer/testdata/operators/mod.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 1
 
 package ExplorerTest api;
diff --git a/explorer/testdata/operators/mod_builtin.carbon b/explorer/testdata/operators/mod_builtin.carbon
index 0f79054af306..459c5ef80779 100644
--- a/explorer/testdata/operators/mod_builtin.carbon
+++ b/explorer/testdata/operators/mod_builtin.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: Interface: 2
 // CHECK:STDOUT: Op: 2
 // CHECK:STDOUT: result: 0
diff --git a/explorer/testdata/operators/mod_edges.carbon b/explorer/testdata/operators/mod_edges.carbon
index 248bdd13f461..6683eb7e95af 100644
--- a/explorer/testdata/operators/mod_edges.carbon
+++ b/explorer/testdata/operators/mod_edges.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/operators/mul.carbon b/explorer/testdata/operators/mul.carbon
index 9ac8ed5420eb..563fb444bdb2 100644
--- a/explorer/testdata/operators/mul.carbon
+++ b/explorer/testdata/operators/mul.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 10
 
 package ExplorerTest api;
diff --git a/explorer/testdata/operators/mul_builtin.carbon b/explorer/testdata/operators/mul_builtin.carbon
index 03a699ff108f..044ecfdf5a3d 100644
--- a/explorer/testdata/operators/mul_builtin.carbon
+++ b/explorer/testdata/operators/mul_builtin.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: Interface: 6
 // CHECK:STDOUT: Op: 6
 // CHECK:STDOUT: result: 0
diff --git a/explorer/testdata/operators/negate.carbon b/explorer/testdata/operators/negate.carbon
index 6b9a6e0b7deb..419fc51ab88a 100644
--- a/explorer/testdata/operators/negate.carbon
+++ b/explorer/testdata/operators/negate.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: -5
 
 package ExplorerTest api;
diff --git a/explorer/testdata/operators/negate_builtin.carbon b/explorer/testdata/operators/negate_builtin.carbon
index 15acbfe5656a..afa92d5cfbef 100644
--- a/explorer/testdata/operators/negate_builtin.carbon
+++ b/explorer/testdata/operators/negate_builtin.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: Interface: -3
 // CHECK:STDOUT: Op: -3
 // CHECK:STDOUT: result: 0
diff --git a/explorer/testdata/operators/right_shift.carbon b/explorer/testdata/operators/right_shift.carbon
index ede1284055fb..eb6f3a03e69a 100644
--- a/explorer/testdata/operators/right_shift.carbon
+++ b/explorer/testdata/operators/right_shift.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 2
 
 package ExplorerTest api;
diff --git a/explorer/testdata/operators/shift.carbon b/explorer/testdata/operators/shift.carbon
index fd4885c3c494..4aa182a8fd87 100644
--- a/explorer/testdata/operators/shift.carbon
+++ b/explorer/testdata/operators/shift.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/operators/shortcircuit_and.carbon b/explorer/testdata/operators/shortcircuit_and.carbon
index 75ea29407416..b7a0ee8a900b 100644
--- a/explorer/testdata/operators/shortcircuit_and.carbon
+++ b/explorer/testdata/operators/shortcircuit_and.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 1
 
 package ExplorerTest api;
diff --git a/explorer/testdata/operators/shortcircuit_and_no_shortcircuit.carbon b/explorer/testdata/operators/shortcircuit_and_no_shortcircuit.carbon
index 0ceea4becaec..3be15aef3299 100644
--- a/explorer/testdata/operators/shortcircuit_and_no_shortcircuit.carbon
+++ b/explorer/testdata/operators/shortcircuit_and_no_shortcircuit.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 2
 
 package ExplorerTest api;
diff --git a/explorer/testdata/operators/shortcircuit_or.carbon b/explorer/testdata/operators/shortcircuit_or.carbon
index 0b950ba0fc26..5d27472e6b72 100644
--- a/explorer/testdata/operators/shortcircuit_or.carbon
+++ b/explorer/testdata/operators/shortcircuit_or.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 1
 
 package ExplorerTest api;
diff --git a/explorer/testdata/operators/shortcircuit_or_no_shortcircuit.carbon b/explorer/testdata/operators/shortcircuit_or_no_shortcircuit.carbon
index ddd55d099daf..9c03229f000b 100644
--- a/explorer/testdata/operators/shortcircuit_or_no_shortcircuit.carbon
+++ b/explorer/testdata/operators/shortcircuit_or_no_shortcircuit.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 2
 
 package ExplorerTest api;
diff --git a/explorer/testdata/operators/sub.carbon b/explorer/testdata/operators/sub.carbon
index f929dabc4f34..995028fa0ac4 100644
--- a/explorer/testdata/operators/sub.carbon
+++ b/explorer/testdata/operators/sub.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 4
 
 package ExplorerTest api;
diff --git a/explorer/testdata/operators/sub_builtin.carbon b/explorer/testdata/operators/sub_builtin.carbon
index 65e5c489be65..8c7fff71d695 100644
--- a/explorer/testdata/operators/sub_builtin.carbon
+++ b/explorer/testdata/operators/sub_builtin.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: Interface: 5
 // CHECK:STDOUT: Op: 5
 // CHECK:STDOUT: result: 0
diff --git a/explorer/testdata/optional/init_optional_with_non_value.carbon b/explorer/testdata/optional/init_optional_with_non_value.carbon
index 88463a8ed255..ed0939490134 100644
--- a/explorer/testdata/optional/init_optional_with_non_value.carbon
+++ b/explorer/testdata/optional/init_optional_with_non_value.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/optional/init_optional_with_value.carbon b/explorer/testdata/optional/init_optional_with_value.carbon
index 661588889589..6178f3d75558 100644
--- a/explorer/testdata/optional/init_optional_with_value.carbon
+++ b/explorer/testdata/optional/init_optional_with_value.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: Hallo Welt
 // CHECK:STDOUT: result: 0
 
diff --git a/explorer/testdata/package/fail_missing.carbon b/explorer/testdata/package/fail_missing.carbon
index 15c566c56ae3..70289f2d6e6b 100644
--- a/explorer/testdata/package/fail_missing.carbon
+++ b/explorer/testdata/package/fail_missing.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 // CHECK:STDERR: SYNTAX ERROR: {{.*}}/explorer/testdata/package/fail_missing.carbon:[[@LINE+1]]: syntax error, unexpected FN, expecting PACKAGE
 fn Main() -> i32 {
diff --git a/explorer/testdata/package/with_library.carbon b/explorer/testdata/package/with_library.carbon
index 2d1e282ae86d..816f35f2eb56 100644
--- a/explorer/testdata/package/with_library.carbon
+++ b/explorer/testdata/package/with_library.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest library "Foo" api;
diff --git a/explorer/testdata/pointer/aliasing.carbon b/explorer/testdata/pointer/aliasing.carbon
index 37c8ee3bc98a..7d81d219a567 100644
--- a/explorer/testdata/pointer/aliasing.carbon
+++ b/explorer/testdata/pointer/aliasing.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/pointer/basic.carbon b/explorer/testdata/pointer/basic.carbon
index 95d1d3dd488c..bf0d27543104 100644
--- a/explorer/testdata/pointer/basic.carbon
+++ b/explorer/testdata/pointer/basic.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/pointer/fail_rvalue_addressof.carbon b/explorer/testdata/pointer/fail_rvalue_addressof.carbon
index 6146e4bd0e52..245e7c47affc 100644
--- a/explorer/testdata/pointer/fail_rvalue_addressof.carbon
+++ b/explorer/testdata/pointer/fail_rvalue_addressof.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/pointer/fail_use_after_free.carbon b/explorer/testdata/pointer/fail_use_after_free.carbon
index 228500c62949..4b50ac2eb9ae 100644
--- a/explorer/testdata/pointer/fail_use_after_free.carbon
+++ b/explorer/testdata/pointer/fail_use_after_free.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/pointer/heap_alloc_lifetime.carbon b/explorer/testdata/pointer/heap_alloc_lifetime.carbon
index d87f89270a68..98f815c4aca4 100644
--- a/explorer/testdata/pointer/heap_alloc_lifetime.carbon
+++ b/explorer/testdata/pointer/heap_alloc_lifetime.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/pointer/intrinsic_new.carbon b/explorer/testdata/pointer/intrinsic_new.carbon
index b795d3f11589..46a09a4729f5 100644
--- a/explorer/testdata/pointer/intrinsic_new.carbon
+++ b/explorer/testdata/pointer/intrinsic_new.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/pointer/new_and_delete.carbon b/explorer/testdata/pointer/new_and_delete.carbon
index 77b8fdfad806..e96e48cbec55 100644
--- a/explorer/testdata/pointer/new_and_delete.carbon
+++ b/explorer/testdata/pointer/new_and_delete.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/pointer/struct_pointer.carbon b/explorer/testdata/pointer/struct_pointer.carbon
index 2380879fdc05..653d21352912 100644
--- a/explorer/testdata/pointer/struct_pointer.carbon
+++ b/explorer/testdata/pointer/struct_pointer.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/print/associated_constant.carbon b/explorer/testdata/print/associated_constant.carbon
index 49f8e8b9ef22..a215259a8db3 100644
--- a/explorer/testdata/print/associated_constant.carbon
+++ b/explorer/testdata/print/associated_constant.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: i32
 // CHECK:STDOUT: String
 // CHECK:STDOUT: result: 0
diff --git a/explorer/testdata/print/fail_no_args.carbon b/explorer/testdata/print/fail_no_args.carbon
index bbdbcaca935f..8357ebb747bf 100644
--- a/explorer/testdata/print/fail_no_args.carbon
+++ b/explorer/testdata/print/fail_no_args.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/print/fail_not_str.carbon b/explorer/testdata/print/fail_not_str.carbon
index e102be9ffb3d..3fe7f46b4673 100644
--- a/explorer/testdata/print/fail_not_str.carbon
+++ b/explorer/testdata/print/fail_not_str.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/print/fail_too_many_args.carbon b/explorer/testdata/print/fail_too_many_args.carbon
index b3574eb54400..b71f93552fb3 100644
--- a/explorer/testdata/print/fail_too_many_args.carbon
+++ b/explorer/testdata/print/fail_too_many_args.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/print/fail_type.carbon b/explorer/testdata/print/fail_type.carbon
index 3352fa6bc8ec..dddcb8091f60 100644
--- a/explorer/testdata/print/fail_type.carbon
+++ b/explorer/testdata/print/fail_type.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/print/format_only.carbon b/explorer/testdata/print/format_only.carbon
index c95bdc23a09a..7895f050884e 100644
--- a/explorer/testdata/print/format_only.carbon
+++ b/explorer/testdata/print/format_only.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: Hello world!
 // CHECK:STDOUT: result: 0
 
diff --git a/explorer/testdata/print/i32.carbon b/explorer/testdata/print/i32.carbon
index bee6ea62b2b4..e4400e585c5a 100644
--- a/explorer/testdata/print/i32.carbon
+++ b/explorer/testdata/print/i32.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: Printing 1
 // CHECK:STDOUT: result: 0
 
diff --git a/explorer/testdata/random/random.carbon b/explorer/testdata/random/random.carbon
index 70fa986b9da9..8ce1493e6e9f 100644
--- a/explorer/testdata/random/random.carbon
+++ b/explorer/testdata/random/random.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: Nice!
 // CHECK:STDOUT: result: 0
 
diff --git a/explorer/testdata/return/convert_return_value.carbon b/explorer/testdata/return/convert_return_value.carbon
index f72f7d535041..f160904608a5 100644
--- a/explorer/testdata/return/convert_return_value.carbon
+++ b/explorer/testdata/return/convert_return_value.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 42
 
 package ExplorerTest api;
diff --git a/explorer/testdata/return/explicit_empty.carbon b/explorer/testdata/return/explicit_empty.carbon
index 11ad24ee12e0..f0461c283786 100644
--- a/explorer/testdata/return/explicit_empty.carbon
+++ b/explorer/testdata/return/explicit_empty.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/return/fail_explicit_with_no_return.carbon b/explorer/testdata/return/fail_explicit_with_no_return.carbon
index e69ea126a507..bbbad92d9ce7 100644
--- a/explorer/testdata/return/fail_explicit_with_no_return.carbon
+++ b/explorer/testdata/return/fail_explicit_with_no_return.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/return/fail_explicit_with_plain_return.carbon b/explorer/testdata/return/fail_explicit_with_plain_return.carbon
index 28efb8b816fd..d3192e3954ad 100644
--- a/explorer/testdata/return/fail_explicit_with_plain_return.carbon
+++ b/explorer/testdata/return/fail_explicit_with_plain_return.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/return/fail_implicit_with_explicit_return.carbon b/explorer/testdata/return/fail_implicit_with_explicit_return.carbon
index 81e214865bc4..a0bf3040c62b 100644
--- a/explorer/testdata/return/fail_implicit_with_explicit_return.carbon
+++ b/explorer/testdata/return/fail_implicit_with_explicit_return.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/return/implicit_with_no_return.carbon b/explorer/testdata/return/implicit_with_no_return.carbon
index 70a6130b5ed7..70f834c226b8 100644
--- a/explorer/testdata/return/implicit_with_no_return.carbon
+++ b/explorer/testdata/return/implicit_with_no_return.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/return/implicit_with_plain_return.carbon b/explorer/testdata/return/implicit_with_plain_return.carbon
index 13f7d5148ef9..8bded969d09e 100644
--- a/explorer/testdata/return/implicit_with_plain_return.carbon
+++ b/explorer/testdata/return/implicit_with_plain_return.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/returned_var/fail_duplicate_return_var.carbon b/explorer/testdata/returned_var/fail_duplicate_return_var.carbon
index 6856535e144b..88eb8a79a7c4 100644
--- a/explorer/testdata/returned_var/fail_duplicate_return_var.carbon
+++ b/explorer/testdata/returned_var/fail_duplicate_return_var.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/returned_var/fail_missing_declaration.carbon b/explorer/testdata/returned_var/fail_missing_declaration.carbon
index 8e45d1a64671..55b1677ae5bc 100644
--- a/explorer/testdata/returned_var/fail_missing_declaration.carbon
+++ b/explorer/testdata/returned_var/fail_missing_declaration.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/returned_var/fail_missing_return.carbon b/explorer/testdata/returned_var/fail_missing_return.carbon
index 5684ebbc9adf..00016a896251 100644
--- a/explorer/testdata/returned_var/fail_missing_return.carbon
+++ b/explorer/testdata/returned_var/fail_missing_return.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/returned_var/fail_returned_var_mismatch_signature.carbon b/explorer/testdata/returned_var/fail_returned_var_mismatch_signature.carbon
index 082083450c0f..1fc944eb2070 100644
--- a/explorer/testdata/returned_var/fail_returned_var_mismatch_signature.carbon
+++ b/explorer/testdata/returned_var/fail_returned_var_mismatch_signature.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/returned_var/fail_returned_var_multi_auto.carbon b/explorer/testdata/returned_var/fail_returned_var_multi_auto.carbon
index 25e2c7b8d02b..4e69e1dae958 100644
--- a/explorer/testdata/returned_var/fail_returned_var_multi_auto.carbon
+++ b/explorer/testdata/returned_var/fail_returned_var_multi_auto.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/returned_var/fail_returned_var_type_mismatch.carbon b/explorer/testdata/returned_var/fail_returned_var_type_mismatch.carbon
index 1c0b78e5e2d4..2f0baa8c89b4 100644
--- a/explorer/testdata/returned_var/fail_returned_var_type_mismatch.carbon
+++ b/explorer/testdata/returned_var/fail_returned_var_type_mismatch.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/returned_var/multiple_returned_var_control_flow.carbon b/explorer/testdata/returned_var/multiple_returned_var_control_flow.carbon
index ad2e52762ef0..0242aff067db 100644
--- a/explorer/testdata/returned_var/multiple_returned_var_control_flow.carbon
+++ b/explorer/testdata/returned_var/multiple_returned_var_control_flow.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 1
 
 package ExplorerTest api;
diff --git a/explorer/testdata/returned_var/normal_return_control_flow.carbon b/explorer/testdata/returned_var/normal_return_control_flow.carbon
index 2e1139f66299..fac047cf4d9c 100644
--- a/explorer/testdata/returned_var/normal_return_control_flow.carbon
+++ b/explorer/testdata/returned_var/normal_return_control_flow.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 3
 
 package ExplorerTest api;
diff --git a/explorer/testdata/returned_var/returned_var_auto.carbon b/explorer/testdata/returned_var/returned_var_auto.carbon
index cf32fef59798..cbae7c6d0a4a 100644
--- a/explorer/testdata/returned_var/returned_var_auto.carbon
+++ b/explorer/testdata/returned_var/returned_var_auto.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 3
 
 package ExplorerTest api;
diff --git a/explorer/testdata/returned_var/returned_var_basic.carbon b/explorer/testdata/returned_var/returned_var_basic.carbon
index 8c5966a0e246..fbd717498dbb 100644
--- a/explorer/testdata/returned_var/returned_var_basic.carbon
+++ b/explorer/testdata/returned_var/returned_var_basic.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 3
 
 package ExplorerTest api;
diff --git a/explorer/testdata/returned_var/returned_var_name_lookup.carbon b/explorer/testdata/returned_var/returned_var_name_lookup.carbon
index 8f2f95a3a8a6..652b36cb78c8 100644
--- a/explorer/testdata/returned_var/returned_var_name_lookup.carbon
+++ b/explorer/testdata/returned_var/returned_var_name_lookup.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 1
 
 package ExplorerTest api;
diff --git a/explorer/testdata/returned_var/returned_var_omitted_expression.carbon b/explorer/testdata/returned_var/returned_var_omitted_expression.carbon
index 4d926d560c76..68f71df93a17 100644
--- a/explorer/testdata/returned_var/returned_var_omitted_expression.carbon
+++ b/explorer/testdata/returned_var/returned_var_omitted_expression.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/string/basic.carbon b/explorer/testdata/string/basic.carbon
index 404c68f8e0e8..136cbde740b6 100644
--- a/explorer/testdata/string/basic.carbon
+++ b/explorer/testdata/string/basic.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/string/block.carbon b/explorer/testdata/string/block.carbon
index fa8697a8913d..9c9211053cb6 100644
--- a/explorer/testdata/string/block.carbon
+++ b/explorer/testdata/string/block.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/string/block_escaped_triple_quotes.carbon b/explorer/testdata/string/block_escaped_triple_quotes.carbon
index 19206973079d..f3caeb0fcd31 100644
--- a/explorer/testdata/string/block_escaped_triple_quotes.carbon
+++ b/explorer/testdata/string/block_escaped_triple_quotes.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/string/block_file_type_indicator.carbon b/explorer/testdata/string/block_file_type_indicator.carbon
index 9a4d7e5c3db9..784679d47536 100644
--- a/explorer/testdata/string/block_file_type_indicator.carbon
+++ b/explorer/testdata/string/block_file_type_indicator.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/string/fail_block_quotes_not_on_own_line.carbon b/explorer/testdata/string/fail_block_quotes_not_on_own_line.carbon
index f13c687d07e1..392a441401e1 100644
--- a/explorer/testdata/string/fail_block_quotes_not_on_own_line.carbon
+++ b/explorer/testdata/string/fail_block_quotes_not_on_own_line.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/string/fail_hex_lower.carbon b/explorer/testdata/string/fail_hex_lower.carbon
index cdf47f468a9f..7c431c25827b 100644
--- a/explorer/testdata/string/fail_hex_lower.carbon
+++ b/explorer/testdata/string/fail_hex_lower.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/string/fail_hex_truncated.carbon b/explorer/testdata/string/fail_hex_truncated.carbon
index 9d8a3a3d198f..b005de934b98 100644
--- a/explorer/testdata/string/fail_hex_truncated.carbon
+++ b/explorer/testdata/string/fail_hex_truncated.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/string/fail_invalid_escape.carbon b/explorer/testdata/string/fail_invalid_escape.carbon
index bbb5e5d448cb..33c2a963c9e6 100644
--- a/explorer/testdata/string/fail_invalid_escape.carbon
+++ b/explorer/testdata/string/fail_invalid_escape.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/string/fail_newline.carbon b/explorer/testdata/string/fail_newline.carbon
index ec01d61cbd9f..53a1066399fc 100644
--- a/explorer/testdata/string/fail_newline.carbon
+++ b/explorer/testdata/string/fail_newline.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/string/fail_octal.carbon b/explorer/testdata/string/fail_octal.carbon
index 70b0357bd02c..3a4123af87b4 100644
--- a/explorer/testdata/string/fail_octal.carbon
+++ b/explorer/testdata/string/fail_octal.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/string/fail_raw_block_more_hash_tags_on_left.carbon b/explorer/testdata/string/fail_raw_block_more_hash_tags_on_left.carbon
index fa9c09e52bf0..423562045047 100644
--- a/explorer/testdata/string/fail_raw_block_more_hash_tags_on_left.carbon
+++ b/explorer/testdata/string/fail_raw_block_more_hash_tags_on_left.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/string/fail_raw_block_more_hash_tags_on_right.carbon b/explorer/testdata/string/fail_raw_block_more_hash_tags_on_right.carbon
index 9ea2092359eb..e038eb82b7a8 100644
--- a/explorer/testdata/string/fail_raw_block_more_hash_tags_on_right.carbon
+++ b/explorer/testdata/string/fail_raw_block_more_hash_tags_on_right.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/string/fail_raw_block_quotes_not_on_own_line.carbon b/explorer/testdata/string/fail_raw_block_quotes_not_on_own_line.carbon
index 7aff5322a830..68befe9cce7e 100644
--- a/explorer/testdata/string/fail_raw_block_quotes_not_on_own_line.carbon
+++ b/explorer/testdata/string/fail_raw_block_quotes_not_on_own_line.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/string/fail_raw_block_single_line.carbon b/explorer/testdata/string/fail_raw_block_single_line.carbon
index 8b5728f0391e..5a86763f024c 100644
--- a/explorer/testdata/string/fail_raw_block_single_line.carbon
+++ b/explorer/testdata/string/fail_raw_block_single_line.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/string/fail_raw_more_hash_tags_on_left.carbon b/explorer/testdata/string/fail_raw_more_hash_tags_on_left.carbon
index 129877c9cf23..3cc3837fea0f 100644
--- a/explorer/testdata/string/fail_raw_more_hash_tags_on_left.carbon
+++ b/explorer/testdata/string/fail_raw_more_hash_tags_on_left.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/string/fail_raw_more_hash_tags_on_right.carbon b/explorer/testdata/string/fail_raw_more_hash_tags_on_right.carbon
index a2e58deddd3b..759b788ccd8a 100644
--- a/explorer/testdata/string/fail_raw_more_hash_tags_on_right.carbon
+++ b/explorer/testdata/string/fail_raw_more_hash_tags_on_right.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/string/fail_tab.carbon b/explorer/testdata/string/fail_tab.carbon
index b25404479231..d6e65af93df5 100644
--- a/explorer/testdata/string/fail_tab.carbon
+++ b/explorer/testdata/string/fail_tab.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/string/hex.carbon b/explorer/testdata/string/hex.carbon
index f3d424d81f06..6027f397cdcb 100644
--- a/explorer/testdata/string/hex.carbon
+++ b/explorer/testdata/string/hex.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/string/newline.carbon b/explorer/testdata/string/newline.carbon
index d5442b5f4d71..ce36c51a411f 100644
--- a/explorer/testdata/string/newline.carbon
+++ b/explorer/testdata/string/newline.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/string/raw_basic.carbon b/explorer/testdata/string/raw_basic.carbon
index 73b9f5fc0c51..f6c0bb17b730 100644
--- a/explorer/testdata/string/raw_basic.carbon
+++ b/explorer/testdata/string/raw_basic.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/string/raw_basic_multi_hashtag.carbon b/explorer/testdata/string/raw_basic_multi_hashtag.carbon
index 7f787c8ecfa0..6b0e67200c96 100644
--- a/explorer/testdata/string/raw_basic_multi_hashtag.carbon
+++ b/explorer/testdata/string/raw_basic_multi_hashtag.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/string/raw_block.carbon b/explorer/testdata/string/raw_block.carbon
index b112f8a62f1a..cc9c1c8c41ba 100644
--- a/explorer/testdata/string/raw_block.carbon
+++ b/explorer/testdata/string/raw_block.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/string/raw_block_escaped_back_slash.carbon b/explorer/testdata/string/raw_block_escaped_back_slash.carbon
index 6fcf60870729..b9025deef47e 100644
--- a/explorer/testdata/string/raw_block_escaped_back_slash.carbon
+++ b/explorer/testdata/string/raw_block_escaped_back_slash.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/string/raw_block_escaped_triple_quotes.carbon b/explorer/testdata/string/raw_block_escaped_triple_quotes.carbon
index 6c3dc888e875..ca29608555bd 100644
--- a/explorer/testdata/string/raw_block_escaped_triple_quotes.carbon
+++ b/explorer/testdata/string/raw_block_escaped_triple_quotes.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/string/raw_nesting.carbon b/explorer/testdata/string/raw_nesting.carbon
index cd62aa55de08..c5ac6afef68c 100644
--- a/explorer/testdata/string/raw_nesting.carbon
+++ b/explorer/testdata/string/raw_nesting.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/string/unicode.carbon b/explorer/testdata/string/unicode.carbon
index a5834fe64e93..8663b076437e 100644
--- a/explorer/testdata/string/unicode.carbon
+++ b/explorer/testdata/string/unicode.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/struct/assign.carbon b/explorer/testdata/struct/assign.carbon
index 8eeef86a04a3..e310af8ca076 100644
--- a/explorer/testdata/struct/assign.carbon
+++ b/explorer/testdata/struct/assign.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/struct/assign_member.carbon b/explorer/testdata/struct/assign_member.carbon
index 51ade3941a88..8648cac5d922 100644
--- a/explorer/testdata/struct/assign_member.carbon
+++ b/explorer/testdata/struct/assign_member.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/struct/empty.carbon b/explorer/testdata/struct/empty.carbon
index 75b9aca5aa77..e21daa50fa0b 100644
--- a/explorer/testdata/struct/empty.carbon
+++ b/explorer/testdata/struct/empty.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/struct/ending_comma.carbon b/explorer/testdata/struct/ending_comma.carbon
index 69076a1898a7..0fec290cf012 100644
--- a/explorer/testdata/struct/ending_comma.carbon
+++ b/explorer/testdata/struct/ending_comma.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/struct/equality.carbon b/explorer/testdata/struct/equality.carbon
index ddecaaf824d2..7c17926dc40c 100644
--- a/explorer/testdata/struct/equality.carbon
+++ b/explorer/testdata/struct/equality.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: t1 == t2: 1
 // CHECK:STDOUT: t1 != t2: 0
 // CHECK:STDOUT: result: 0
diff --git a/explorer/testdata/struct/equality_false.carbon b/explorer/testdata/struct/equality_false.carbon
index ae52b7d42fe9..cb5d5a3ea681 100644
--- a/explorer/testdata/struct/equality_false.carbon
+++ b/explorer/testdata/struct/equality_false.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/struct/fail_equality_type.carbon b/explorer/testdata/struct/fail_equality_type.carbon
index 6b0a6be7c8ad..a01e304613b4 100644
--- a/explorer/testdata/struct/fail_equality_type.carbon
+++ b/explorer/testdata/struct/fail_equality_type.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/struct/fail_field_access_mismatch.carbon b/explorer/testdata/struct/fail_field_access_mismatch.carbon
index 472d14af7823..70b5954d8f05 100644
--- a/explorer/testdata/struct/fail_field_access_mismatch.carbon
+++ b/explorer/testdata/struct/fail_field_access_mismatch.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/struct/name_order.carbon b/explorer/testdata/struct/name_order.carbon
index c85f69a0c34c..ffc8b7d9c0b4 100644
--- a/explorer/testdata/struct/name_order.carbon
+++ b/explorer/testdata/struct/name_order.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/struct/temp.carbon b/explorer/testdata/struct/temp.carbon
index ad7ad5e22687..b7d9ed2b2737 100644
--- a/explorer/testdata/struct/temp.carbon
+++ b/explorer/testdata/struct/temp.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/struct/var.carbon b/explorer/testdata/struct/var.carbon
index 68a893b8e6a2..9fcc58642ab9 100644
--- a/explorer/testdata/struct/var.carbon
+++ b/explorer/testdata/struct/var.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/tuple/ending_comma.carbon b/explorer/testdata/tuple/ending_comma.carbon
index 3cecdfbd23fd..589e1cb88bc4 100644
--- a/explorer/testdata/tuple/ending_comma.carbon
+++ b/explorer/testdata/tuple/ending_comma.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/tuple/equality.carbon b/explorer/testdata/tuple/equality.carbon
index f445ed0dd323..9fc8216520a8 100644
--- a/explorer/testdata/tuple/equality.carbon
+++ b/explorer/testdata/tuple/equality.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/tuple/equality_false.carbon b/explorer/testdata/tuple/equality_false.carbon
index f4d506afd579..03068e1fc377 100644
--- a/explorer/testdata/tuple/equality_false.carbon
+++ b/explorer/testdata/tuple/equality_false.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/tuple/fail_equality_type.carbon b/explorer/testdata/tuple/fail_equality_type.carbon
index a4567f99db84..74099c9e6121 100644
--- a/explorer/testdata/tuple/fail_equality_type.carbon
+++ b/explorer/testdata/tuple/fail_equality_type.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/tuple/fail_index.carbon b/explorer/testdata/tuple/fail_index.carbon
index 44c00162720e..d7cfa7fc878d 100644
--- a/explorer/testdata/tuple/fail_index.carbon
+++ b/explorer/testdata/tuple/fail_index.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/tuple/fail_index_var.carbon b/explorer/testdata/tuple/fail_index_var.carbon
index f0520a63f848..3b39c170eb08 100644
--- a/explorer/testdata/tuple/fail_index_var.carbon
+++ b/explorer/testdata/tuple/fail_index_var.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/tuple/fail_to_array.carbon b/explorer/testdata/tuple/fail_to_array.carbon
index eee5b123604b..0241c3710111 100644
--- a/explorer/testdata/tuple/fail_to_array.carbon
+++ b/explorer/testdata/tuple/fail_to_array.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/tuple/index.carbon b/explorer/testdata/tuple/index.carbon
index af01033ac4a7..8c4beeb72ed8 100644
--- a/explorer/testdata/tuple/index.carbon
+++ b/explorer/testdata/tuple/index.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/tuple/match.carbon b/explorer/testdata/tuple/match.carbon
index 3b3cac31b740..a51e44391a8b 100644
--- a/explorer/testdata/tuple/match.carbon
+++ b/explorer/testdata/tuple/match.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/tuple/match_nested.carbon b/explorer/testdata/tuple/match_nested.carbon
index 5e1a8237a5b4..2c0a4a1357cb 100644
--- a/explorer/testdata/tuple/match_nested.carbon
+++ b/explorer/testdata/tuple/match_nested.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/tuple/no_ending_comma.carbon b/explorer/testdata/tuple/no_ending_comma.carbon
index ab27c3e72518..419c224eb57d 100644
--- a/explorer/testdata/tuple/no_ending_comma.carbon
+++ b/explorer/testdata/tuple/no_ending_comma.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/tuple/to_array.carbon b/explorer/testdata/tuple/to_array.carbon
index 74ed068d1e8c..828d294a9247 100644
--- a/explorer/testdata/tuple/to_array.carbon
+++ b/explorer/testdata/tuple/to_array.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 3
 
 package ExplorerTest api;
diff --git a/explorer/testdata/unformed/control_flow_defer_to_dynamic.carbon b/explorer/testdata/unformed/control_flow_defer_to_dynamic.carbon
index 86e60e58b709..316954113d81 100644
--- a/explorer/testdata/unformed/control_flow_defer_to_dynamic.carbon
+++ b/explorer/testdata/unformed/control_flow_defer_to_dynamic.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/unformed/dynamic/fail_global.carbon b/explorer/testdata/unformed/dynamic/fail_global.carbon
index fef3a23ca6db..e43e26bad94c 100644
--- a/explorer/testdata/unformed/dynamic/fail_global.carbon
+++ b/explorer/testdata/unformed/dynamic/fail_global.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/unformed/dynamic/fail_param.carbon b/explorer/testdata/unformed/dynamic/fail_param.carbon
index e7d8f03aa125..958d3fca29b5 100644
--- a/explorer/testdata/unformed/dynamic/fail_param.carbon
+++ b/explorer/testdata/unformed/dynamic/fail_param.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/unformed/dynamic/fail_pattern_declare.carbon b/explorer/testdata/unformed/dynamic/fail_pattern_declare.carbon
index 213ca64d3aa8..00e565f3acab 100644
--- a/explorer/testdata/unformed/dynamic/fail_pattern_declare.carbon
+++ b/explorer/testdata/unformed/dynamic/fail_pattern_declare.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/unformed/dynamic/fail_return.carbon b/explorer/testdata/unformed/dynamic/fail_return.carbon
index 76328ddcc376..5cdc29227f95 100644
--- a/explorer/testdata/unformed/dynamic/fail_return.carbon
+++ b/explorer/testdata/unformed/dynamic/fail_return.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/unformed/dynamic/fail_returned_var.carbon b/explorer/testdata/unformed/dynamic/fail_returned_var.carbon
index c85757d1e9d9..39c87e33b397 100644
--- a/explorer/testdata/unformed/dynamic/fail_returned_var.carbon
+++ b/explorer/testdata/unformed/dynamic/fail_returned_var.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/unformed/dynamic/fail_rhs_assign.carbon b/explorer/testdata/unformed/dynamic/fail_rhs_assign.carbon
index c3f2cd6043b1..47c048fe8d80 100644
--- a/explorer/testdata/unformed/dynamic/fail_rhs_assign.carbon
+++ b/explorer/testdata/unformed/dynamic/fail_rhs_assign.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/unformed/global_assign_before_use.carbon b/explorer/testdata/unformed/global_assign_before_use.carbon
index 687209e489af..845e6b4b26ee 100644
--- a/explorer/testdata/unformed/global_assign_before_use.carbon
+++ b/explorer/testdata/unformed/global_assign_before_use.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 1
 
 package ExplorerTest api;
diff --git a/explorer/testdata/unformed/global_escape.carbon b/explorer/testdata/unformed/global_escape.carbon
index 62af1da6bb71..daf23da23bd0 100644
--- a/explorer/testdata/unformed/global_escape.carbon
+++ b/explorer/testdata/unformed/global_escape.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 42
 
 package ExplorerTest api;
diff --git a/explorer/testdata/unformed/global_unformed_without_use.carbon b/explorer/testdata/unformed/global_unformed_without_use.carbon
index a96ceb6ae2f4..28e4b20965cb 100644
--- a/explorer/testdata/unformed/global_unformed_without_use.carbon
+++ b/explorer/testdata/unformed/global_unformed_without_use.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 1
 
 package ExplorerTest api;
diff --git a/explorer/testdata/unformed/local_assign_before_use.carbon b/explorer/testdata/unformed/local_assign_before_use.carbon
index 4fda3d7a7e7c..3d063644b54b 100644
--- a/explorer/testdata/unformed/local_assign_before_use.carbon
+++ b/explorer/testdata/unformed/local_assign_before_use.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 1
 
 package ExplorerTest api;
diff --git a/explorer/testdata/unformed/local_escape.carbon b/explorer/testdata/unformed/local_escape.carbon
index c757589cc2f0..cf5dd4520e09 100644
--- a/explorer/testdata/unformed/local_escape.carbon
+++ b/explorer/testdata/unformed/local_escape.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 42
 
 package ExplorerTest api;
diff --git a/explorer/testdata/unformed/local_unformed_without_use.carbon b/explorer/testdata/unformed/local_unformed_without_use.carbon
index 7ef6b9f9dd98..099b06bc02fb 100644
--- a/explorer/testdata/unformed/local_unformed_without_use.carbon
+++ b/explorer/testdata/unformed/local_unformed_without_use.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 1
 
 package ExplorerTest api;
diff --git a/explorer/testdata/unformed/pattern_declare.carbon b/explorer/testdata/unformed/pattern_declare.carbon
index 335a9e186b98..2728b67348f5 100644
--- a/explorer/testdata/unformed/pattern_declare.carbon
+++ b/explorer/testdata/unformed/pattern_declare.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 1
 
 package ExplorerTest api;
diff --git a/explorer/testdata/unformed/returned_var_assign_before_use.carbon b/explorer/testdata/unformed/returned_var_assign_before_use.carbon
index 099615dd81ed..c911d743fb3f 100644
--- a/explorer/testdata/unformed/returned_var_assign_before_use.carbon
+++ b/explorer/testdata/unformed/returned_var_assign_before_use.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 1
 
 package ExplorerTest api;
diff --git a/explorer/testdata/unformed/static/fail_field_value.carbon b/explorer/testdata/unformed/static/fail_field_value.carbon
index f13d1cfc0fcc..c0d906b9234c 100644
--- a/explorer/testdata/unformed/static/fail_field_value.carbon
+++ b/explorer/testdata/unformed/static/fail_field_value.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/unformed/static/fail_if_cond.carbon b/explorer/testdata/unformed/static/fail_if_cond.carbon
index ee19243533ab..a9fb9e723149 100644
--- a/explorer/testdata/unformed/static/fail_if_cond.carbon
+++ b/explorer/testdata/unformed/static/fail_if_cond.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/unformed/static/fail_if_else.carbon b/explorer/testdata/unformed/static/fail_if_else.carbon
index d8c6a94432e4..39f96db14aca 100644
--- a/explorer/testdata/unformed/static/fail_if_else.carbon
+++ b/explorer/testdata/unformed/static/fail_if_else.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/unformed/static/fail_if_then.carbon b/explorer/testdata/unformed/static/fail_if_then.carbon
index 90e797db8672..aa51987868fd 100644
--- a/explorer/testdata/unformed/static/fail_if_then.carbon
+++ b/explorer/testdata/unformed/static/fail_if_then.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/unformed/static/fail_local_pattern_declare.carbon b/explorer/testdata/unformed/static/fail_local_pattern_declare.carbon
index 010a855f1fcc..6abf714eb2c9 100644
--- a/explorer/testdata/unformed/static/fail_local_pattern_declare.carbon
+++ b/explorer/testdata/unformed/static/fail_local_pattern_declare.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/unformed/static/fail_local_rhs_assign.carbon b/explorer/testdata/unformed/static/fail_local_rhs_assign.carbon
index d4fd5849767c..86c0b3ad6329 100644
--- a/explorer/testdata/unformed/static/fail_local_rhs_assign.carbon
+++ b/explorer/testdata/unformed/static/fail_local_rhs_assign.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/unformed/static/fail_match_clause.carbon b/explorer/testdata/unformed/static/fail_match_clause.carbon
index 9da58ea7fa2f..ce8d0fff08f7 100644
--- a/explorer/testdata/unformed/static/fail_match_clause.carbon
+++ b/explorer/testdata/unformed/static/fail_match_clause.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/unformed/static/fail_match_expression.carbon b/explorer/testdata/unformed/static/fail_match_expression.carbon
index 0cce364a94dc..667212fa9365 100644
--- a/explorer/testdata/unformed/static/fail_match_expression.carbon
+++ b/explorer/testdata/unformed/static/fail_match_expression.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/unformed/static/fail_param.carbon b/explorer/testdata/unformed/static/fail_param.carbon
index 117c3db83e5c..7a73b86e9c25 100644
--- a/explorer/testdata/unformed/static/fail_param.carbon
+++ b/explorer/testdata/unformed/static/fail_param.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/unformed/static/fail_return.carbon b/explorer/testdata/unformed/static/fail_return.carbon
index 3506ab095fb0..fa83ed8f2a42 100644
--- a/explorer/testdata/unformed/static/fail_return.carbon
+++ b/explorer/testdata/unformed/static/fail_return.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/unformed/static/fail_returned_var.carbon b/explorer/testdata/unformed/static/fail_returned_var.carbon
index 247010881d51..0f79fa50257c 100644
--- a/explorer/testdata/unformed/static/fail_returned_var.carbon
+++ b/explorer/testdata/unformed/static/fail_returned_var.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/unformed/static/fail_rhs_def.carbon b/explorer/testdata/unformed/static/fail_rhs_def.carbon
index 086b5e521aa4..4c83059d2c03 100644
--- a/explorer/testdata/unformed/static/fail_rhs_def.carbon
+++ b/explorer/testdata/unformed/static/fail_rhs_def.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/unformed/static/fail_struct_member_access.carbon b/explorer/testdata/unformed/static/fail_struct_member_access.carbon
index 20460a47638f..49d61e590897 100644
--- a/explorer/testdata/unformed/static/fail_struct_member_access.carbon
+++ b/explorer/testdata/unformed/static/fail_struct_member_access.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/unformed/static/fail_while_body.carbon b/explorer/testdata/unformed/static/fail_while_body.carbon
index d093c0a67d25..b0ffd8ef786b 100644
--- a/explorer/testdata/unformed/static/fail_while_body.carbon
+++ b/explorer/testdata/unformed/static/fail_while_body.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/unformed/static/fail_while_cond.carbon b/explorer/testdata/unformed/static/fail_while_cond.carbon
index 5cf5279d5c43..103e6d3a6b01 100644
--- a/explorer/testdata/unformed/static/fail_while_cond.carbon
+++ b/explorer/testdata/unformed/static/fail_while_cond.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{not} %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{not} %{explorer-run}
+// RUN: %{not} %{explorer-run-trace}
 
 package ExplorerTest api;
 
diff --git a/explorer/testdata/while/basic.carbon b/explorer/testdata/while/basic.carbon
index 4d9ec3f3027e..8ab902f07f3a 100644
--- a/explorer/testdata/while/basic.carbon
+++ b/explorer/testdata/while/basic.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/while/break.carbon b/explorer/testdata/while/break.carbon
index b56ef83bfe14..655d59d33b82 100644
--- a/explorer/testdata/while/break.carbon
+++ b/explorer/testdata/while/break.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/while/continue.carbon b/explorer/testdata/while/continue.carbon
index 64896f562e84..87a206a72c60 100644
--- a/explorer/testdata/while/continue.carbon
+++ b/explorer/testdata/while/continue.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/explorer/testdata/while/convert_condition.carbon b/explorer/testdata/while/convert_condition.carbon
index 08ea21aee452..fb58c0b0e423 100644
--- a/explorer/testdata/while/convert_condition.carbon
+++ b/explorer/testdata/while/convert_condition.carbon
@@ -2,9 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{explorer} %s | %{FileCheck-strict} %s
-// RUN: %{explorer-trace} %s | %{FileCheck-allow-unmatched} %s
-// AUTOUPDATE: %{explorer} %s
+// AUTOUPDATE
+// RUN: %{explorer-run}
+// RUN: %{explorer-run-trace}
 // CHECK:STDOUT: result: 0
 
 package ExplorerTest api;
diff --git a/toolchain/driver/testdata/errors_sorted_test.carbon b/toolchain/driver/testdata/errors_sorted_test.carbon
index aad3411a2166..de9ddf8ec1d6 100644
--- a/toolchain/driver/testdata/errors_sorted_test.carbon
+++ b/toolchain/driver/testdata/errors_sorted_test.carbon
@@ -2,7 +2,7 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{carbon} dump tokens %s | %{FileCheck-strict} %s
+// RUN: %{not} %{carbon-run-tokens}
 // CHECK-COUNT-17:STDOUT: token: {{.*}}
 
 // CHECK:STDERR: {{.*}}/errors_sorted_test.carbon:[[@LINE+1]]:24: Closing symbol does not match most recent opening symbol.
diff --git a/toolchain/driver/testdata/errors_streamed_test.carbon b/toolchain/driver/testdata/errors_streamed_test.carbon
index eea1be098886..84d28551b696 100644
--- a/toolchain/driver/testdata/errors_streamed_test.carbon
+++ b/toolchain/driver/testdata/errors_streamed_test.carbon
@@ -3,7 +3,7 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // RUN: %{not} %{carbon} --print-errors=streamed dump tokens %s | \
-// RUN:   %{FileCheck-strict} %s
+// RUN:   %{FileCheck-strict}
 // CHECK-COUNT-17:STDOUT: token: {{.*}}
 
 fn run(String program) {
diff --git a/toolchain/lexer/lit_autoupdate.py b/toolchain/lexer/lit_autoupdate.py
index 25715e30c416..8f489d8cf3b0 100755
--- a/toolchain/lexer/lit_autoupdate.py
+++ b/toolchain/lexer/lit_autoupdate.py
@@ -14,8 +14,8 @@ from pathlib import Path
 
 
 def main() -> None:
-    # Calls the main script with lexer settings. This uses execv in order to
-    # avoid Python import behaviors.
+    # Calls the main script using execv in order to avoid Python import
+    # behaviors.
     this_py = Path(__file__).resolve()
     actual_py = this_py.parent.parent.parent.joinpath(
         "bazel", "testing", "lit_autoupdate_base.py"
@@ -23,8 +23,9 @@ def main() -> None:
     args = [
         sys.argv[0],
         # Flags to configure for lexer testing.
-        "--build_target",
-        "//toolchain/driver:carbon",
+        "--tool=carbon",
+        "--autoupdate_arg=dump",
+        "--autoupdate_arg=tokens",
         # Ignore the resulting column of EndOfFile because it's typically the
         # end of the CHECK comment.
         "--extra_check_replacement",
@@ -32,12 +33,10 @@ def main() -> None:
         r"column: (?:\d+)",
         "column: {{[0-9]+}}",
         # Ignore spaces that are used to columnize lines.
-        "--line_number_format",
-        "{{ *}}[[@LINE%(delta)s]]",
-        "--line_number_pattern",
-        r"(?<= line: )( *\d+)(?=,)",
-        "--testdata",
-        "toolchain/lexer/testdata",
+        "--line_number_format={{ *}}[[@LINE%(delta)s]]",
+        r"--line_number_pattern=(?<= line: )( *\d+)(?=,)",
+        "--lit_run=%{carbon-run-tokens}",
+        "--testdata=toolchain/lexer/testdata",
     ] + sys.argv[1:]
     os.execv(actual_py, args)
 
diff --git a/toolchain/lexer/testdata/carbon_test.carbon b/toolchain/lexer/testdata/carbon_test.carbon
index 8d20ea6506ab..eeb4f10d0351 100644
--- a/toolchain/lexer/testdata/carbon_test.carbon
+++ b/toolchain/lexer/testdata/carbon_test.carbon
@@ -2,21 +2,21 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{carbon} dump tokens %s | %{FileCheck-strict} %s
-// AUTOUPDATE: %{carbon} dump tokens %s
+// AUTOUPDATE
+// RUN: %{carbon-run-tokens}
 
-// CHECK:STDOUT: token: { index:  0, kind:              'Fn', line: {{ *}}[[@LINE+7]], column:   1, indent: 1, spelling: 'fn', has_trailing_space: true }
-// CHECK:STDOUT: token: { index:  1, kind:      'Identifier', line: {{ *}}[[@LINE+6]], column:   4, indent: 1, spelling: 'run', identifier: 0 }
-// CHECK:STDOUT: token: { index:  2, kind:       'OpenParen', line: {{ *}}[[@LINE+5]], column:   7, indent: 1, spelling: '(', closing_token: 5 }
-// CHECK:STDOUT: token: { index:  3, kind:      'Identifier', line: {{ *}}[[@LINE+4]], column:   8, indent: 1, spelling: 'String', identifier: 1, has_trailing_space: true }
-// CHECK:STDOUT: token: { index:  4, kind:      'Identifier', line: {{ *}}[[@LINE+3]], column:  15, indent: 1, spelling: 'program', identifier: 2 }
-// CHECK:STDOUT: token: { index:  5, kind:      'CloseParen', line: {{ *}}[[@LINE+2]], column:  22, indent: 1, spelling: ')', opening_token: 2, has_trailing_space: true }
-// CHECK:STDOUT: token: { index:  6, kind:  'OpenCurlyBrace', line: {{ *}}[[@LINE+1]], column:  24, indent: 1, spelling: '{', closing_token: 10, has_trailing_space: true }
+// CHECK:STDOUT: token: { index:  0, kind:              'Fn', line: {{ *}}[[@LINE+7]], column:  1, indent: 1, spelling: 'fn', has_trailing_space: true }
+// CHECK:STDOUT: token: { index:  1, kind:      'Identifier', line: {{ *}}[[@LINE+6]], column:  4, indent: 1, spelling: 'run', identifier: 0 }
+// CHECK:STDOUT: token: { index:  2, kind:       'OpenParen', line: {{ *}}[[@LINE+5]], column:  7, indent: 1, spelling: '(', closing_token: 5 }
+// CHECK:STDOUT: token: { index:  3, kind:      'Identifier', line: {{ *}}[[@LINE+4]], column:  8, indent: 1, spelling: 'String', identifier: 1, has_trailing_space: true }
+// CHECK:STDOUT: token: { index:  4, kind:      'Identifier', line: {{ *}}[[@LINE+3]], column: 15, indent: 1, spelling: 'program', identifier: 2 }
+// CHECK:STDOUT: token: { index:  5, kind:      'CloseParen', line: {{ *}}[[@LINE+2]], column: 22, indent: 1, spelling: ')', opening_token: 2, has_trailing_space: true }
+// CHECK:STDOUT: token: { index:  6, kind:  'OpenCurlyBrace', line: {{ *}}[[@LINE+1]], column: 24, indent: 1, spelling: '{', closing_token: 10, has_trailing_space: true }
 fn run(String program) {
-  // CHECK:STDOUT: token: { index:  7, kind:          'Return', line: {{ *}}[[@LINE+3]], column:   3, indent: 3, spelling: 'return', has_trailing_space: true }
-  // CHECK:STDOUT: token: { index:  8, kind:      'Identifier', line: {{ *}}[[@LINE+2]], column:  10, indent: 3, spelling: 'True', identifier: 3 }
-  // CHECK:STDOUT: token: { index:  9, kind:            'Semi', line: {{ *}}[[@LINE+1]], column:  14, indent: 3, spelling: ';', has_trailing_space: true }
+  // CHECK:STDOUT: token: { index:  7, kind:          'Return', line: {{ *}}[[@LINE+3]], column:  3, indent: 3, spelling: 'return', has_trailing_space: true }
+  // CHECK:STDOUT: token: { index:  8, kind:      'Identifier', line: {{ *}}[[@LINE+2]], column: 10, indent: 3, spelling: 'True', identifier: 3 }
+  // CHECK:STDOUT: token: { index:  9, kind:            'Semi', line: {{ *}}[[@LINE+1]], column: 14, indent: 3, spelling: ';', has_trailing_space: true }
   return True;
-// CHECK:STDOUT: token: { index: 10, kind: 'CloseCurlyBrace', line: {{ *}}[[@LINE+1]], column:   1, indent: 1, spelling: '}', opening_token: 6, has_trailing_space: true }
+// CHECK:STDOUT: token: { index: 10, kind: 'CloseCurlyBrace', line: {{ *}}[[@LINE+2]], column:  1, indent: 1, spelling: '}', opening_token: 6, has_trailing_space: true }
+// CHECK:STDOUT: token: { index: 11, kind:       'EndOfFile', line: {{ *}}[[@LINE+1]], column:  2, indent: 1, spelling: '' }
 }
-// CHECK:STDOUT: token: { index: 11, kind:       'EndOfFile', line: {{ *}}[[@LINE+0]], column: {{[0-9]+}}, indent: 1, spelling: '' }
diff --git a/toolchain/parser/lit_autoupdate.py b/toolchain/parser/lit_autoupdate.py
index b24ad2f9d2bb..a7b3aca633c0 100755
--- a/toolchain/parser/lit_autoupdate.py
+++ b/toolchain/parser/lit_autoupdate.py
@@ -14,21 +14,21 @@ from pathlib import Path
 
 
 def main() -> None:
-    # Calls the main script with explorer settings. This uses execv in order to
-    # avoid Python import behaviors.
+    # Calls the main script using execv in order to avoid Python import
+    # behaviors.
     this_py = Path(__file__).resolve()
     actual_py = this_py.parent.parent.parent.joinpath(
         "bazel", "testing", "lit_autoupdate_base.py"
     )
     args = [
         sys.argv[0],
-        # Flags to configure for explorer testing.
-        "--build_target",
-        "//toolchain/driver:carbon",
-        "--line_number_pattern",
-        r"(?<=\.carbon:)(\d+)(?=(?:\D|$))",
-        "--testdata",
-        "toolchain/parser/testdata",
+        # Flags to configure for parser testing.
+        "--tool=carbon",
+        "--autoupdate_arg=dump",
+        "--autoupdate_arg=parse-tree",
+        r"--line_number_pattern=(?<=\.carbon:)(\d+)(?=(?:\D|$))",
+        "--lit_run=%{carbon-run-parser}",
+        "--testdata=toolchain/parser/testdata",
     ] + sys.argv[1:]
     os.execv(actual_py, args)
 
diff --git a/toolchain/parser/testdata/basics/empty.carbon b/toolchain/parser/testdata/basics/empty.carbon
index 72a42338695f..0af91192b498 100644
--- a/toolchain/parser/testdata/basics/empty.carbon
+++ b/toolchain/parser/testdata/basics/empty.carbon
@@ -2,8 +2,8 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{carbon} dump parse-tree %s | %{FileCheck-strict} %s
-// AUTOUPDATE: %{carbon} dump parse-tree %s
+// AUTOUPDATE
+// RUN: %{carbon-run-parser}
 // CHECK:STDOUT: [
 // CHECK:STDOUT: {node_index: 0, kind: 'FileEnd', text: ''},
 // CHECK:STDOUT: ]
diff --git a/toolchain/parser/testdata/basics/empty_declaration.carbon b/toolchain/parser/testdata/basics/empty_declaration.carbon
index 26cfd23252d9..f13b771fcde2 100644
--- a/toolchain/parser/testdata/basics/empty_declaration.carbon
+++ b/toolchain/parser/testdata/basics/empty_declaration.carbon
@@ -2,8 +2,8 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{carbon} dump parse-tree %s | %{FileCheck-strict} %s
-// AUTOUPDATE: %{carbon} dump parse-tree %s
+// AUTOUPDATE
+// RUN: %{carbon-run-parser}
 // CHECK:STDOUT: [
 // CHECK:STDOUT: {node_index: 0, kind: 'EmptyDeclaration', text: ';'},
 // CHECK:STDOUT: {node_index: 1, kind: 'FileEnd', text: ''},
diff --git a/toolchain/parser/testdata/basics/invalid_designators.carbon b/toolchain/parser/testdata/basics/fail_invalid_designators.carbon
similarity index 79%
rename from toolchain/parser/testdata/basics/invalid_designators.carbon
rename to toolchain/parser/testdata/basics/fail_invalid_designators.carbon
index 1af22cc8ad22..7d7e68928144 100644
--- a/toolchain/parser/testdata/basics/invalid_designators.carbon
+++ b/toolchain/parser/testdata/basics/fail_invalid_designators.carbon
@@ -2,8 +2,8 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{carbon} dump parse-tree %s | %{FileCheck-strict} %s
-// AUTOUPDATE: %{carbon} dump parse-tree %s
+// AUTOUPDATE
+// RUN: %{not} %{carbon-run-parser}
 // CHECK:STDOUT: [
 // CHECK:STDOUT: {node_index: 15, kind: 'FunctionDeclaration', text: 'fn', subtree_size: 16, children: [
 // CHECK:STDOUT:   {node_index: 0, kind: 'DeclaredName', text: 'F'},
@@ -26,10 +26,10 @@
 
 // NOTE: Move to its own directory when more tests are added.
 fn F() {
-  // CHECK:STDERR: {{.*}}/toolchain/parser/testdata/basics/invalid_designators.carbon:[[@LINE+1]]:5: Expected identifier after `.`.
+  // CHECK:STDERR: {{.*}}/toolchain/parser/testdata/basics/fail_invalid_designators.carbon:[[@LINE+1]]:5: Expected identifier after `.`.
   a.;
-  // CHECK:STDERR: {{.*}}/toolchain/parser/testdata/basics/invalid_designators.carbon:[[@LINE+1]]:5: Expected identifier after `.`.
+  // CHECK:STDERR: {{.*}}/toolchain/parser/testdata/basics/fail_invalid_designators.carbon:[[@LINE+1]]:5: Expected identifier after `.`.
   a.fn;
-  // CHECK:STDERR: {{.*}}/toolchain/parser/testdata/basics/invalid_designators.carbon:[[@LINE+1]]:5: Expected identifier after `.`.
+  // CHECK:STDERR: {{.*}}/toolchain/parser/testdata/basics/fail_invalid_designators.carbon:[[@LINE+1]]:5: Expected identifier after `.`.
   a.42;
 }
diff --git a/toolchain/parser/testdata/basics/no_intro_with_semi.carbon b/toolchain/parser/testdata/basics/fail_no_intro_with_semi.carbon
similarity index 60%
rename from toolchain/parser/testdata/basics/no_intro_with_semi.carbon
rename to toolchain/parser/testdata/basics/fail_no_intro_with_semi.carbon
index 61e614ddcc59..76b238aa7347 100644
--- a/toolchain/parser/testdata/basics/no_intro_with_semi.carbon
+++ b/toolchain/parser/testdata/basics/fail_no_intro_with_semi.carbon
@@ -2,12 +2,12 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{carbon} dump parse-tree %s | %{FileCheck-strict} %s
-// AUTOUPDATE: %{carbon} dump parse-tree %s
+// AUTOUPDATE
+// RUN: %{not} %{carbon-run-parser}
 // CHECK:STDOUT: [
 // CHECK:STDOUT: {node_index: 0, kind: 'EmptyDeclaration', text: ';', has_error: yes},
 // CHECK:STDOUT: {node_index: 1, kind: 'FileEnd', text: ''},
 // CHECK:STDOUT: ]
 
-// CHECK:STDERR: {{.*}}/toolchain/parser/testdata/basics/no_intro_with_semi.carbon:[[@LINE+1]]:1: Unrecognized declaration introducer.
+// CHECK:STDERR: {{.*}}/toolchain/parser/testdata/basics/fail_no_intro_with_semi.carbon:[[@LINE+1]]:1: Unrecognized declaration introducer.
 foo;
diff --git a/toolchain/parser/testdata/basics/no_intro_without_semi.carbon b/toolchain/parser/testdata/basics/fail_no_intro_without_semi.carbon
similarity index 55%
rename from toolchain/parser/testdata/basics/no_intro_without_semi.carbon
rename to toolchain/parser/testdata/basics/fail_no_intro_without_semi.carbon
index ed170f49ffa0..f8bb40818f7f 100644
--- a/toolchain/parser/testdata/basics/no_intro_without_semi.carbon
+++ b/toolchain/parser/testdata/basics/fail_no_intro_without_semi.carbon
@@ -2,11 +2,11 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{carbon} dump parse-tree %s | %{FileCheck-strict} %s
-// AUTOUPDATE: %{carbon} dump parse-tree %s
+// AUTOUPDATE
+// RUN: %{not} %{carbon-run-parser}
 // CHECK:STDOUT: [
 // CHECK:STDOUT: {node_index: 0, kind: 'FileEnd', text: ''},
 // CHECK:STDOUT: ]
 
-// CHECK:STDERR: {{.*}}/toolchain/parser/testdata/basics/no_intro_without_semi.carbon:[[@LINE+1]]:1: Unrecognized declaration introducer.
+// CHECK:STDERR: {{.*}}/toolchain/parser/testdata/basics/fail_no_intro_without_semi.carbon:[[@LINE+1]]:1: Unrecognized declaration introducer.
 foo bar baz
diff --git a/toolchain/parser/testdata/basics/paren_match_regression.carbon b/toolchain/parser/testdata/basics/fail_paren_match_regression.carbon
similarity index 61%
rename from toolchain/parser/testdata/basics/paren_match_regression.carbon
rename to toolchain/parser/testdata/basics/fail_paren_match_regression.carbon
index 3c134e48e139..0acbfe8aa701 100644
--- a/toolchain/parser/testdata/basics/paren_match_regression.carbon
+++ b/toolchain/parser/testdata/basics/fail_paren_match_regression.carbon
@@ -2,8 +2,8 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{carbon} dump parse-tree %s | %{FileCheck-strict} %s
-// AUTOUPDATE: %{carbon} dump parse-tree %s
+// AUTOUPDATE
+// RUN: %{not} %{carbon-run-parser}
 // CHECK:STDOUT: [
 // CHECK:STDOUT: {node_index: 4, kind: 'VariableDeclaration', text: 'var', has_error: yes, subtree_size: 5, children: [
 // CHECK:STDOUT:   {node_index: 3, kind: 'VariableInitializer', text: '=', subtree_size: 4, children: [
@@ -13,7 +13,7 @@
 // CHECK:STDOUT: {node_index: 5, kind: 'FileEnd', text: ''},
 // CHECK:STDOUT: ]
 
-// CHECK:STDERR: {{.*}}/toolchain/parser/testdata/basics/paren_match_regression.carbon:[[@LINE+3]]:5: Expected pattern in `var` declaration.
-// CHECK:STDERR: {{.*}}/toolchain/parser/testdata/basics/paren_match_regression.carbon:[[@LINE+2]]:12: Expected `,` or `)`.
-// CHECK:STDERR: {{.*}}/toolchain/parser/testdata/basics/paren_match_regression.carbon:[[@LINE+1]]:15: Expected `;` after expression.
+// CHECK:STDERR: {{.*}}/toolchain/parser/testdata/basics/fail_paren_match_regression.carbon:[[@LINE+3]]:5: Expected pattern in `var` declaration.
+// CHECK:STDERR: {{.*}}/toolchain/parser/testdata/basics/fail_paren_match_regression.carbon:[[@LINE+2]]:12: Expected `,` or `)`.
+// CHECK:STDERR: {{.*}}/toolchain/parser/testdata/basics/fail_paren_match_regression.carbon:[[@LINE+1]]:15: Expected `;` after expression.
 var = (foo {})
diff --git a/toolchain/parser/testdata/basics/function_call.carbon b/toolchain/parser/testdata/basics/function_call.carbon
index 20429b3e761b..5294b6809343 100644
--- a/toolchain/parser/testdata/basics/function_call.carbon
+++ b/toolchain/parser/testdata/basics/function_call.carbon
@@ -2,8 +2,8 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{carbon} dump parse-tree %s | %{FileCheck-strict} %s
-// AUTOUPDATE: %{carbon} dump parse-tree %s
+// AUTOUPDATE
+// RUN: %{carbon-run-parser}
 // CHECK:STDOUT: [
 // CHECK:STDOUT: {node_index: 24, kind: 'FunctionDeclaration', text: 'fn', subtree_size: 25, children: [
 // CHECK:STDOUT:   {node_index: 0, kind: 'DeclaredName', text: 'F'},
diff --git a/toolchain/parser/testdata/basics/package.carbon b/toolchain/parser/testdata/basics/package.carbon
index 875d694f4c99..8256379fc69f 100644
--- a/toolchain/parser/testdata/basics/package.carbon
+++ b/toolchain/parser/testdata/basics/package.carbon
@@ -2,8 +2,8 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{carbon} dump parse-tree %s | %{FileCheck-strict} %s
-// AUTOUPDATE: %{carbon} dump parse-tree %s
+// AUTOUPDATE
+// RUN: %{carbon-run-parser}
 // CHECK:STDOUT: [
 // CHECK:STDOUT: {node_index: 3, kind: 'PackageDirective', text: 'package', subtree_size: 4, children: [
 // CHECK:STDOUT:   {node_index: 0, kind: 'DeclaredName', text: 'Geometry'},
diff --git a/toolchain/parser/testdata/basics/return.carbon b/toolchain/parser/testdata/basics/return.carbon
index fd879eee7576..4780a5ef9223 100644
--- a/toolchain/parser/testdata/basics/return.carbon
+++ b/toolchain/parser/testdata/basics/return.carbon
@@ -2,8 +2,8 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{carbon} dump parse-tree %s | %{FileCheck-strict} %s
-// AUTOUPDATE: %{carbon} dump parse-tree %s
+// AUTOUPDATE
+// RUN: %{carbon-run-parser}
 // CHECK:STDOUT: [
 // CHECK:STDOUT: {node_index: 13, kind: 'FunctionDeclaration', text: 'fn', subtree_size: 14, children: [
 // CHECK:STDOUT:   {node_index: 0, kind: 'DeclaredName', text: 'F'},
diff --git a/toolchain/parser/testdata/basics/structs.carbon b/toolchain/parser/testdata/basics/structs.carbon
index b36cc7cd6fcd..843c7faec1a7 100644
--- a/toolchain/parser/testdata/basics/structs.carbon
+++ b/toolchain/parser/testdata/basics/structs.carbon
@@ -2,8 +2,8 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{carbon} dump parse-tree %s | %{FileCheck-strict} %s
-// AUTOUPDATE: %{carbon} dump parse-tree %s
+// AUTOUPDATE
+// RUN: %{carbon-run-parser}
 // CHECK:STDOUT: [
 // CHECK:STDOUT: {node_index: 26, kind: 'VariableDeclaration', text: 'var', subtree_size: 27, children: [
 // CHECK:STDOUT:   {node_index: 12, kind: 'PatternBinding', text: ':', subtree_size: 13, children: [
diff --git a/toolchain/parser/testdata/basics/tuples.carbon b/toolchain/parser/testdata/basics/tuples.carbon
index 0087619bd5bc..315ed4e1fcf4 100644
--- a/toolchain/parser/testdata/basics/tuples.carbon
+++ b/toolchain/parser/testdata/basics/tuples.carbon
@@ -2,8 +2,8 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{carbon} dump parse-tree %s | %{FileCheck-strict} %s
-// AUTOUPDATE: %{carbon} dump parse-tree %s
+// AUTOUPDATE
+// RUN: %{carbon-run-parser}
 // CHECK:STDOUT: [
 // CHECK:STDOUT: {node_index: 14, kind: 'VariableDeclaration', text: 'var', subtree_size: 15, children: [
 // CHECK:STDOUT:   {node_index: 6, kind: 'PatternBinding', text: ':', subtree_size: 7, children: [
diff --git a/toolchain/parser/testdata/basics/var.carbon b/toolchain/parser/testdata/basics/var.carbon
index 3bb9b9438381..c84898fd165b 100644
--- a/toolchain/parser/testdata/basics/var.carbon
+++ b/toolchain/parser/testdata/basics/var.carbon
@@ -2,8 +2,8 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{carbon} dump parse-tree %s | %{FileCheck-strict} %s
-// AUTOUPDATE: %{carbon} dump parse-tree %s
+// AUTOUPDATE
+// RUN: %{carbon-run-parser}
 // CHECK:STDOUT: [
 // CHECK:STDOUT: {node_index: 6, kind: 'VariableDeclaration', text: 'var', subtree_size: 7, children: [
 // CHECK:STDOUT:   {node_index: 2, kind: 'PatternBinding', text: ':', subtree_size: 3, children: [
diff --git a/toolchain/parser/testdata/for/colon_instead_of_in.carbon b/toolchain/parser/testdata/for/fail_colon_instead_of_in.carbon
similarity index 90%
rename from toolchain/parser/testdata/for/colon_instead_of_in.carbon
rename to toolchain/parser/testdata/for/fail_colon_instead_of_in.carbon
index 4cd53bf7a46d..907e134f880a 100644
--- a/toolchain/parser/testdata/for/colon_instead_of_in.carbon
+++ b/toolchain/parser/testdata/for/fail_colon_instead_of_in.carbon
@@ -2,8 +2,8 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{carbon} dump parse-tree %s | %{FileCheck-strict} %s
-// AUTOUPDATE: %{carbon} dump parse-tree %s
+// AUTOUPDATE
+// RUN: %{not} %{carbon-run-parser}
 // CHECK:STDOUT: [
 // CHECK:STDOUT: {node_index: 20, kind: 'FunctionDeclaration', text: 'fn', subtree_size: 21, children: [
 // CHECK:STDOUT:   {node_index: 0, kind: 'DeclaredName', text: 'foo'},
@@ -30,7 +30,7 @@
 // CHECK:STDOUT: ]
 
 fn foo() {
-  // CHECK:STDERR: {{.*}}/toolchain/parser/testdata/for/colon_instead_of_in.carbon:[[@LINE+1]]:19: `:` should be replaced by `in`.
+  // CHECK:STDERR: {{.*}}/toolchain/parser/testdata/for/fail_colon_instead_of_in.carbon:[[@LINE+1]]:19: `:` should be replaced by `in`.
   for (var x: i32 : y) {
     Print(x);
   }
diff --git a/toolchain/parser/testdata/for/missing_in.carbon b/toolchain/parser/testdata/for/fail_missing_in.carbon
similarity index 89%
rename from toolchain/parser/testdata/for/missing_in.carbon
rename to toolchain/parser/testdata/for/fail_missing_in.carbon
index f2dec99d4bcc..1dfcd75aeefb 100644
--- a/toolchain/parser/testdata/for/missing_in.carbon
+++ b/toolchain/parser/testdata/for/fail_missing_in.carbon
@@ -2,8 +2,8 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{carbon} dump parse-tree %s | %{FileCheck-strict} %s
-// AUTOUPDATE: %{carbon} dump parse-tree %s
+// AUTOUPDATE
+// RUN: %{not} %{carbon-run-parser}
 // CHECK:STDOUT: [
 // CHECK:STDOUT: {node_index: 19, kind: 'FunctionDeclaration', text: 'fn', subtree_size: 20, children: [
 // CHECK:STDOUT:   {node_index: 0, kind: 'DeclaredName', text: 'foo'},
@@ -29,7 +29,7 @@
 // CHECK:STDOUT: ]
 
 fn foo() {
-  // CHECK:STDERR: {{.*}}/toolchain/parser/testdata/for/missing_in.carbon:[[@LINE+1]]:19: Expected `in` after loop `var` declaration.
+  // CHECK:STDERR: {{.*}}/toolchain/parser/testdata/for/fail_missing_in.carbon:[[@LINE+1]]:19: Expected `in` after loop `var` declaration.
   for (var x: i32 y) {
     Print(x);
   }
diff --git a/toolchain/parser/testdata/for/missing_var.carbon b/toolchain/parser/testdata/for/fail_missing_var.carbon
similarity index 89%
rename from toolchain/parser/testdata/for/missing_var.carbon
rename to toolchain/parser/testdata/for/fail_missing_var.carbon
index 33aedf14d877..c8720cae7d31 100644
--- a/toolchain/parser/testdata/for/missing_var.carbon
+++ b/toolchain/parser/testdata/for/fail_missing_var.carbon
@@ -2,8 +2,8 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{carbon} dump parse-tree %s | %{FileCheck-strict} %s
-// AUTOUPDATE: %{carbon} dump parse-tree %s
+// AUTOUPDATE
+// RUN: %{not} %{carbon-run-parser}
 // CHECK:STDOUT: [
 // CHECK:STDOUT: {node_index: 17, kind: 'FunctionDeclaration', text: 'fn', subtree_size: 18, children: [
 // CHECK:STDOUT:   {node_index: 0, kind: 'DeclaredName', text: 'foo'},
@@ -27,7 +27,7 @@
 // CHECK:STDOUT: ]
 
 fn foo() {
-  // CHECK:STDERR: {{.*}}/toolchain/parser/testdata/for/missing_var.carbon:[[@LINE+1]]:8: Expected `var` declaration.
+  // CHECK:STDERR: {{.*}}/toolchain/parser/testdata/for/fail_missing_var.carbon:[[@LINE+1]]:8: Expected `var` declaration.
   for (x: i32 in y) {
     Print(x);
   }
diff --git a/toolchain/parser/testdata/for/nested.carbon b/toolchain/parser/testdata/for/nested.carbon
index df95c7da3111..849b3ff723d3 100644
--- a/toolchain/parser/testdata/for/nested.carbon
+++ b/toolchain/parser/testdata/for/nested.carbon
@@ -2,8 +2,8 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{carbon} dump parse-tree %s | %{FileCheck-strict} %s
-// AUTOUPDATE: %{carbon} dump parse-tree %s
+// AUTOUPDATE
+// RUN: %{carbon-run-parser}
 // CHECK:STDOUT: [
 // CHECK:STDOUT: {node_index: 32, kind: 'FunctionDeclaration', text: 'fn', subtree_size: 33, children: [
 // CHECK:STDOUT:   {node_index: 0, kind: 'DeclaredName', text: 'foo'},
diff --git a/toolchain/parser/testdata/for/simple.carbon b/toolchain/parser/testdata/for/simple.carbon
index fa26d67e733b..fae5d92f2aa1 100644
--- a/toolchain/parser/testdata/for/simple.carbon
+++ b/toolchain/parser/testdata/for/simple.carbon
@@ -2,8 +2,8 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{carbon} dump parse-tree %s | %{FileCheck-strict} %s
-// AUTOUPDATE: %{carbon} dump parse-tree %s
+// AUTOUPDATE
+// RUN: %{carbon-run-parser}
 // CHECK:STDOUT: [
 // CHECK:STDOUT: {node_index: 21, kind: 'FunctionDeclaration', text: 'fn', subtree_size: 22, children: [
 // CHECK:STDOUT:   {node_index: 0, kind: 'DeclaredName', text: 'foo'},
diff --git a/toolchain/parser/testdata/function/declaration/basic.carbon b/toolchain/parser/testdata/function/declaration/basic.carbon
index 1743d1c1ab61..c587ded55d19 100644
--- a/toolchain/parser/testdata/function/declaration/basic.carbon
+++ b/toolchain/parser/testdata/function/declaration/basic.carbon
@@ -2,8 +2,8 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{carbon} dump parse-tree %s | %{FileCheck-strict} %s
-// AUTOUPDATE: %{carbon} dump parse-tree %s
+// AUTOUPDATE
+// RUN: %{carbon-run-parser}
 // CHECK:STDOUT: [
 // CHECK:STDOUT: {node_index: 4, kind: 'FunctionDeclaration', text: 'fn', subtree_size: 5, children: [
 // CHECK:STDOUT:   {node_index: 0, kind: 'DeclaredName', text: 'F'},
diff --git a/toolchain/parser/testdata/function/declaration/identifier_instead_of_sig.carbon b/toolchain/parser/testdata/function/declaration/fail_identifier_instead_of_sig.carbon
similarity index 75%
rename from toolchain/parser/testdata/function/declaration/identifier_instead_of_sig.carbon
rename to toolchain/parser/testdata/function/declaration/fail_identifier_instead_of_sig.carbon
index bb48c88cab85..d1f527659c90 100644
--- a/toolchain/parser/testdata/function/declaration/identifier_instead_of_sig.carbon
+++ b/toolchain/parser/testdata/function/declaration/fail_identifier_instead_of_sig.carbon
@@ -2,8 +2,8 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{carbon} dump parse-tree %s | %{FileCheck-strict} %s
-// AUTOUPDATE: %{carbon} dump parse-tree %s
+// AUTOUPDATE
+// RUN: %{not} %{carbon-run-parser}
 // CHECK:STDOUT: [
 // CHECK:STDOUT: {node_index: 2, kind: 'FunctionDeclaration', text: 'fn', has_error: yes, subtree_size: 3, children: [
 // CHECK:STDOUT:   {node_index: 0, kind: 'DeclaredName', text: 'foo'},
@@ -11,5 +11,5 @@
 // CHECK:STDOUT: {node_index: 3, kind: 'FileEnd', text: ''},
 // CHECK:STDOUT: ]
 
-// CHECK:STDERR: {{.*}}/toolchain/parser/testdata/function/declaration/identifier_instead_of_sig.carbon:[[@LINE+1]]:8: Expected `(` after function name.
+// CHECK:STDERR: {{.*}}/toolchain/parser/testdata/function/declaration/fail_identifier_instead_of_sig.carbon:[[@LINE+1]]:8: Expected `(` after function name.
 fn foo bar;
diff --git a/toolchain/parser/testdata/function/declaration/missing_name.carbon b/toolchain/parser/testdata/function/declaration/fail_missing_name.carbon
similarity index 73%
rename from toolchain/parser/testdata/function/declaration/missing_name.carbon
rename to toolchain/parser/testdata/function/declaration/fail_missing_name.carbon
index 5d366ba89037..87ceefa60631 100644
--- a/toolchain/parser/testdata/function/declaration/missing_name.carbon
+++ b/toolchain/parser/testdata/function/declaration/fail_missing_name.carbon
@@ -2,13 +2,13 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{carbon} dump parse-tree %s | %{FileCheck-strict} %s
-// AUTOUPDATE: %{carbon} dump parse-tree %s
+// AUTOUPDATE
+// RUN: %{not} %{carbon-run-parser}
 // CHECK:STDOUT: [
 // CHECK:STDOUT: {node_index: 1, kind: 'FunctionDeclaration', text: 'fn', has_error: yes, subtree_size: 2, children: [
 // CHECK:STDOUT:   {node_index: 0, kind: 'DeclarationEnd', text: ';'}]},
 // CHECK:STDOUT: {node_index: 2, kind: 'FileEnd', text: ''},
 // CHECK:STDOUT: ]
 
-// CHECK:STDERR: {{.*}}/toolchain/parser/testdata/function/declaration/missing_name.carbon:[[@LINE+1]]:4: Expected function name after `fn` keyword.
+// CHECK:STDERR: {{.*}}/toolchain/parser/testdata/function/declaration/fail_missing_name.carbon:[[@LINE+1]]:4: Expected function name after `fn` keyword.
 fn ();
diff --git a/toolchain/parser/testdata/function/declaration/no_sig_or_semi.carbon b/toolchain/parser/testdata/function/declaration/fail_no_sig_or_semi.carbon
similarity index 74%
rename from toolchain/parser/testdata/function/declaration/no_sig_or_semi.carbon
rename to toolchain/parser/testdata/function/declaration/fail_no_sig_or_semi.carbon
index effdf253e0b5..ed0c9443971d 100644
--- a/toolchain/parser/testdata/function/declaration/no_sig_or_semi.carbon
+++ b/toolchain/parser/testdata/function/declaration/fail_no_sig_or_semi.carbon
@@ -2,13 +2,13 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{carbon} dump parse-tree %s | %{FileCheck-strict} %s
-// AUTOUPDATE: %{carbon} dump parse-tree %s
+// AUTOUPDATE
+// RUN: %{not} %{carbon-run-parser}
 // CHECK:STDOUT: [
 // CHECK:STDOUT: {node_index: 1, kind: 'FunctionDeclaration', text: 'fn', has_error: yes, subtree_size: 2, children: [
 // CHECK:STDOUT:   {node_index: 0, kind: 'DeclaredName', text: 'foo'}]},
 // CHECK:STDOUT: {node_index: 2, kind: 'FileEnd', text: ''},
 // CHECK:STDOUT: ]
 
-// CHECK:STDERR: {{.*}}/toolchain/parser/testdata/function/declaration/no_sig_or_semi.carbon:[[@LINE+1]]:7: Expected `(` after function name.
+// CHECK:STDERR: {{.*}}/toolchain/parser/testdata/function/declaration/fail_no_sig_or_semi.carbon:[[@LINE+1]]:7: Expected `(` after function name.
 fn foo
diff --git a/toolchain/parser/testdata/function/declaration/only_fn_and_semi.carbon b/toolchain/parser/testdata/function/declaration/fail_only_fn_and_semi.carbon
similarity index 73%
rename from toolchain/parser/testdata/function/declaration/only_fn_and_semi.carbon
rename to toolchain/parser/testdata/function/declaration/fail_only_fn_and_semi.carbon
index 68825a8a6039..2bc5c00b82aa 100644
--- a/toolchain/parser/testdata/function/declaration/only_fn_and_semi.carbon
+++ b/toolchain/parser/testdata/function/declaration/fail_only_fn_and_semi.carbon
@@ -2,13 +2,13 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{carbon} dump parse-tree %s | %{FileCheck-strict} %s
-// AUTOUPDATE: %{carbon} dump parse-tree %s
+// AUTOUPDATE
+// RUN: %{not} %{carbon-run-parser}
 // CHECK:STDOUT: [
 // CHECK:STDOUT: {node_index: 1, kind: 'FunctionDeclaration', text: 'fn', has_error: yes, subtree_size: 2, children: [
 // CHECK:STDOUT:   {node_index: 0, kind: 'DeclarationEnd', text: ';'}]},
 // CHECK:STDOUT: {node_index: 2, kind: 'FileEnd', text: ''},
 // CHECK:STDOUT: ]
 
-// CHECK:STDERR: {{.*}}/toolchain/parser/testdata/function/declaration/only_fn_and_semi.carbon:[[@LINE+1]]:3: Expected function name after `fn` keyword.
+// CHECK:STDERR: {{.*}}/toolchain/parser/testdata/function/declaration/fail_only_fn_and_semi.carbon:[[@LINE+1]]:3: Expected function name after `fn` keyword.
 fn;
diff --git a/toolchain/parser/testdata/function/declaration/repeated_fn_and_semi.carbon b/toolchain/parser/testdata/function/declaration/fail_repeated_fn_and_semi.carbon
similarity index 73%
rename from toolchain/parser/testdata/function/declaration/repeated_fn_and_semi.carbon
rename to toolchain/parser/testdata/function/declaration/fail_repeated_fn_and_semi.carbon
index 8be2c76d3627..1efb9a7c1cf9 100644
--- a/toolchain/parser/testdata/function/declaration/repeated_fn_and_semi.carbon
+++ b/toolchain/parser/testdata/function/declaration/fail_repeated_fn_and_semi.carbon
@@ -2,13 +2,13 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{carbon} dump parse-tree %s | %{FileCheck-strict} %s
-// AUTOUPDATE: %{carbon} dump parse-tree %s
+// AUTOUPDATE
+// RUN: %{not} %{carbon-run-parser}
 // CHECK:STDOUT: [
 // CHECK:STDOUT: {node_index: 1, kind: 'FunctionDeclaration', text: 'fn', has_error: yes, subtree_size: 2, children: [
 // CHECK:STDOUT:   {node_index: 0, kind: 'DeclarationEnd', text: ';'}]},
 // CHECK:STDOUT: {node_index: 2, kind: 'FileEnd', text: ''},
 // CHECK:STDOUT: ]
 
-// CHECK:STDERR: {{.*}}/toolchain/parser/testdata/function/declaration/repeated_fn_and_semi.carbon:[[@LINE+1]]:4: Expected function name after `fn` keyword.
+// CHECK:STDERR: {{.*}}/toolchain/parser/testdata/function/declaration/fail_repeated_fn_and_semi.carbon:[[@LINE+1]]:4: Expected function name after `fn` keyword.
 fn fn;
diff --git a/toolchain/parser/testdata/function/declaration/skip_indented_newline_until_outdent.carbon b/toolchain/parser/testdata/function/declaration/fail_skip_indented_newline_until_outdent.carbon
similarity index 80%
rename from toolchain/parser/testdata/function/declaration/skip_indented_newline_until_outdent.carbon
rename to toolchain/parser/testdata/function/declaration/fail_skip_indented_newline_until_outdent.carbon
index 1aaca74656d5..78f4bef3853d 100644
--- a/toolchain/parser/testdata/function/declaration/skip_indented_newline_until_outdent.carbon
+++ b/toolchain/parser/testdata/function/declaration/fail_skip_indented_newline_until_outdent.carbon
@@ -2,8 +2,8 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{carbon} dump parse-tree %s | %{FileCheck-strict} %s
-// AUTOUPDATE: %{carbon} dump parse-tree %s
+// AUTOUPDATE
+// RUN: %{not} %{carbon-run-parser}
 // CHECK:STDOUT: [
 // CHECK:STDOUT: {node_index: 0, kind: 'FunctionDeclaration', text: 'fn', has_error: yes},
 // CHECK:STDOUT: {node_index: 5, kind: 'FunctionDeclaration', text: 'fn', subtree_size: 5, children: [
@@ -14,7 +14,7 @@
 // CHECK:STDOUT: {node_index: 6, kind: 'FileEnd', text: ''},
 // CHECK:STDOUT: ]
 
-  // CHECK:STDERR: {{.*}}/toolchain/parser/testdata/function/declaration/skip_indented_newline_until_outdent.carbon:[[@LINE+1]]:6: Expected function name after `fn` keyword.
+  // CHECK:STDERR: {{.*}}/toolchain/parser/testdata/function/declaration/fail_skip_indented_newline_until_outdent.carbon:[[@LINE+1]]:6: Expected function name after `fn` keyword.
   fn (x,
       y,
       z)
diff --git a/toolchain/parser/testdata/function/declaration/skip_indented_newline_with_semi.carbon b/toolchain/parser/testdata/function/declaration/fail_skip_indented_newline_with_semi.carbon
similarity index 82%
rename from toolchain/parser/testdata/function/declaration/skip_indented_newline_with_semi.carbon
rename to toolchain/parser/testdata/function/declaration/fail_skip_indented_newline_with_semi.carbon
index 9e7ea70c6f08..6dfe690724df 100644
--- a/toolchain/parser/testdata/function/declaration/skip_indented_newline_with_semi.carbon
+++ b/toolchain/parser/testdata/function/declaration/fail_skip_indented_newline_with_semi.carbon
@@ -2,8 +2,8 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{carbon} dump parse-tree %s | %{FileCheck-strict} %s
-// AUTOUPDATE: %{carbon} dump parse-tree %s
+// AUTOUPDATE
+// RUN: %{not} %{carbon-run-parser}
 // CHECK:STDOUT: [
 // CHECK:STDOUT: {node_index: 1, kind: 'FunctionDeclaration', text: 'fn', has_error: yes, subtree_size: 2, children: [
 // CHECK:STDOUT:   {node_index: 0, kind: 'DeclarationEnd', text: ';'}]},
@@ -15,7 +15,7 @@
 // CHECK:STDOUT: {node_index: 7, kind: 'FileEnd', text: ''},
 // CHECK:STDOUT: ]
 
-// CHECK:STDERR: {{.*}}/toolchain/parser/testdata/function/declaration/skip_indented_newline_with_semi.carbon:[[@LINE+1]]:4: Expected function name after `fn` keyword.
+// CHECK:STDERR: {{.*}}/toolchain/parser/testdata/function/declaration/fail_skip_indented_newline_with_semi.carbon:[[@LINE+1]]:4: Expected function name after `fn` keyword.
 fn (x,
     y,
     z);
diff --git a/toolchain/parser/testdata/function/declaration/skip_indented_newline_without_semi.carbon b/toolchain/parser/testdata/function/declaration/fail_skip_indented_newline_without_semi.carbon
similarity index 80%
rename from toolchain/parser/testdata/function/declaration/skip_indented_newline_without_semi.carbon
rename to toolchain/parser/testdata/function/declaration/fail_skip_indented_newline_without_semi.carbon
index 877a4d62e5fa..a37fe5148d85 100644
--- a/toolchain/parser/testdata/function/declaration/skip_indented_newline_without_semi.carbon
+++ b/toolchain/parser/testdata/function/declaration/fail_skip_indented_newline_without_semi.carbon
@@ -2,8 +2,8 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{carbon} dump parse-tree %s | %{FileCheck-strict} %s
-// AUTOUPDATE: %{carbon} dump parse-tree %s
+// AUTOUPDATE
+// RUN: %{not} %{carbon-run-parser}
 // CHECK:STDOUT: [
 // CHECK:STDOUT: {node_index: 0, kind: 'FunctionDeclaration', text: 'fn', has_error: yes},
 // CHECK:STDOUT: {node_index: 5, kind: 'FunctionDeclaration', text: 'fn', subtree_size: 5, children: [
@@ -14,7 +14,7 @@
 // CHECK:STDOUT: {node_index: 6, kind: 'FileEnd', text: ''},
 // CHECK:STDOUT: ]
 
-// CHECK:STDERR: {{.*}}/toolchain/parser/testdata/function/declaration/skip_indented_newline_without_semi.carbon:[[@LINE+1]]:4: Expected function name after `fn` keyword.
+// CHECK:STDERR: {{.*}}/toolchain/parser/testdata/function/declaration/fail_skip_indented_newline_without_semi.carbon:[[@LINE+1]]:4: Expected function name after `fn` keyword.
 fn (x,
     y,
     z)
diff --git a/toolchain/parser/testdata/function/declaration/skip_to_newline_without_semi.carbon b/toolchain/parser/testdata/function/declaration/fail_skip_to_newline_without_semi.carbon
similarity index 80%
rename from toolchain/parser/testdata/function/declaration/skip_to_newline_without_semi.carbon
rename to toolchain/parser/testdata/function/declaration/fail_skip_to_newline_without_semi.carbon
index 256bf702edf3..0d97c5bd2940 100644
--- a/toolchain/parser/testdata/function/declaration/skip_to_newline_without_semi.carbon
+++ b/toolchain/parser/testdata/function/declaration/fail_skip_to_newline_without_semi.carbon
@@ -2,8 +2,8 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{carbon} dump parse-tree %s | %{FileCheck-strict} %s
-// AUTOUPDATE: %{carbon} dump parse-tree %s
+// AUTOUPDATE
+// RUN: %{not} %{carbon-run-parser}
 // CHECK:STDOUT: [
 // CHECK:STDOUT: {node_index: 0, kind: 'FunctionDeclaration', text: 'fn', has_error: yes},
 // CHECK:STDOUT: {node_index: 5, kind: 'FunctionDeclaration', text: 'fn', subtree_size: 5, children: [
@@ -14,6 +14,6 @@
 // CHECK:STDOUT: {node_index: 6, kind: 'FileEnd', text: ''},
 // CHECK:STDOUT: ]
 
-// CHECK:STDERR: {{.*}}/toolchain/parser/testdata/function/declaration/skip_to_newline_without_semi.carbon:[[@LINE+1]]:4: Expected function name after `fn` keyword.
+// CHECK:STDERR: {{.*}}/toolchain/parser/testdata/function/declaration/fail_skip_to_newline_without_semi.carbon:[[@LINE+1]]:4: Expected function name after `fn` keyword.
 fn ()
 fn F();
diff --git a/toolchain/parser/testdata/function/declaration/skip_without_semi_to_curly.carbon b/toolchain/parser/testdata/function/declaration/fail_skip_without_semi_to_curly.carbon
similarity index 79%
rename from toolchain/parser/testdata/function/declaration/skip_without_semi_to_curly.carbon
rename to toolchain/parser/testdata/function/declaration/fail_skip_without_semi_to_curly.carbon
index ad283e38436d..badc7570fdcc 100644
--- a/toolchain/parser/testdata/function/declaration/skip_without_semi_to_curly.carbon
+++ b/toolchain/parser/testdata/function/declaration/fail_skip_without_semi_to_curly.carbon
@@ -2,8 +2,8 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{carbon} dump parse-tree %s | %{FileCheck-strict} %s
-// AUTOUPDATE: %{carbon} dump parse-tree %s
+// AUTOUPDATE
+// RUN: %{not} %{carbon-run-parser}
 // CHECK:STDOUT: [
 // CHECK:STDOUT: {node_index: 4, kind: 'FunctionDeclaration', text: 'fn', subtree_size: 5, children: [
 // CHECK:STDOUT:   {node_index: 0, kind: 'DeclaredName', text: 'F'},
@@ -13,6 +13,6 @@
 // CHECK:STDOUT: {node_index: 5, kind: 'FileEnd', text: ''},
 // CHECK:STDOUT: ]
 
-// CHECK:STDERR: {{.*}}/toolchain/parser/testdata/function/declaration/skip_without_semi_to_curly.carbon:[[@LINE+1]]:1: Unrecognized declaration introducer.
+// CHECK:STDERR: {{.*}}/toolchain/parser/testdata/function/declaration/fail_skip_without_semi_to_curly.carbon:[[@LINE+1]]:1: Unrecognized declaration introducer.
 struct X { fn () }
 fn F();
diff --git a/toolchain/parser/testdata/function/declaration/with_identifier_as_param.carbon b/toolchain/parser/testdata/function/declaration/fail_with_identifier_as_param.carbon
similarity index 80%
rename from toolchain/parser/testdata/function/declaration/with_identifier_as_param.carbon
rename to toolchain/parser/testdata/function/declaration/fail_with_identifier_as_param.carbon
index e8e3cef7f30a..65dd48d1582e 100644
--- a/toolchain/parser/testdata/function/declaration/with_identifier_as_param.carbon
+++ b/toolchain/parser/testdata/function/declaration/fail_with_identifier_as_param.carbon
@@ -2,8 +2,8 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{carbon} dump parse-tree %s | %{FileCheck-strict} %s
-// AUTOUPDATE: %{carbon} dump parse-tree %s
+// AUTOUPDATE
+// RUN: %{not} %{carbon-run-parser}
 // CHECK:STDOUT: [
 // CHECK:STDOUT: {node_index: 4, kind: 'FunctionDeclaration', text: 'fn', subtree_size: 5, children: [
 // CHECK:STDOUT:   {node_index: 0, kind: 'DeclaredName', text: 'foo'},
@@ -13,5 +13,5 @@
 // CHECK:STDOUT: {node_index: 5, kind: 'FileEnd', text: ''},
 // CHECK:STDOUT: ]
 
-// CHECK:STDERR: {{.*}}/toolchain/parser/testdata/function/declaration/with_identifier_as_param.carbon:[[@LINE+1]]:8: Expected parameter declaration.
+// CHECK:STDERR: {{.*}}/toolchain/parser/testdata/function/declaration/fail_with_identifier_as_param.carbon:[[@LINE+1]]:8: Expected parameter declaration.
 fn foo(bar);
diff --git a/toolchain/parser/testdata/function/declaration/without_name_and_many_tokens_in_params.carbon b/toolchain/parser/testdata/function/declaration/fail_without_name_and_many_tokens_in_params.carbon
similarity index 73%
rename from toolchain/parser/testdata/function/declaration/without_name_and_many_tokens_in_params.carbon
rename to toolchain/parser/testdata/function/declaration/fail_without_name_and_many_tokens_in_params.carbon
index f6c0e8d7ce51..a00978bb14a4 100644
--- a/toolchain/parser/testdata/function/declaration/without_name_and_many_tokens_in_params.carbon
+++ b/toolchain/parser/testdata/function/declaration/fail_without_name_and_many_tokens_in_params.carbon
@@ -2,13 +2,13 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{carbon} dump parse-tree %s | %{FileCheck-strict} %s
-// AUTOUPDATE: %{carbon} dump parse-tree %s
+// AUTOUPDATE
+// RUN: %{not} %{carbon-run-parser}
 // CHECK:STDOUT: [
 // CHECK:STDOUT: {node_index: 1, kind: 'FunctionDeclaration', text: 'fn', has_error: yes, subtree_size: 2, children: [
 // CHECK:STDOUT:   {node_index: 0, kind: 'DeclarationEnd', text: ';'}]},
 // CHECK:STDOUT: {node_index: 2, kind: 'FileEnd', text: ''},
 // CHECK:STDOUT: ]
 
-// CHECK:STDERR: {{.*}}/toolchain/parser/testdata/function/declaration/without_name_and_many_tokens_in_params.carbon:[[@LINE+1]]:4: Expected function name after `fn` keyword.
+// CHECK:STDERR: {{.*}}/toolchain/parser/testdata/function/declaration/fail_without_name_and_many_tokens_in_params.carbon:[[@LINE+1]]:4: Expected function name after `fn` keyword.
 fn (a tokens c d e f g h i j k l m n o p q r s t u v w x y z);
diff --git a/toolchain/parser/testdata/function/declaration/with_params.carbon b/toolchain/parser/testdata/function/declaration/with_params.carbon
index 07071d517b11..d43e26e477e0 100644
--- a/toolchain/parser/testdata/function/declaration/with_params.carbon
+++ b/toolchain/parser/testdata/function/declaration/with_params.carbon
@@ -2,8 +2,8 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{carbon} dump parse-tree %s | %{FileCheck-strict} %s
-// AUTOUPDATE: %{carbon} dump parse-tree %s
+// AUTOUPDATE
+// RUN: %{carbon-run-parser}
 // CHECK:STDOUT: [
 // CHECK:STDOUT: {node_index: 11, kind: 'FunctionDeclaration', text: 'fn', subtree_size: 12, children: [
 // CHECK:STDOUT:   {node_index: 0, kind: 'DeclaredName', text: 'foo'},
diff --git a/toolchain/parser/testdata/function/declaration/with_return_type.carbon b/toolchain/parser/testdata/function/declaration/with_return_type.carbon
index a830fa38a407..0e9e64dc7eb8 100644
--- a/toolchain/parser/testdata/function/declaration/with_return_type.carbon
+++ b/toolchain/parser/testdata/function/declaration/with_return_type.carbon
@@ -2,8 +2,8 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{carbon} dump parse-tree %s | %{FileCheck-strict} %s
-// AUTOUPDATE: %{carbon} dump parse-tree %s
+// AUTOUPDATE
+// RUN: %{carbon-run-parser}
 // CHECK:STDOUT: [
 // CHECK:STDOUT: {node_index: 6, kind: 'FunctionDeclaration', text: 'fn', subtree_size: 7, children: [
 // CHECK:STDOUT:   {node_index: 0, kind: 'DeclaredName', text: 'foo'},
diff --git a/toolchain/parser/testdata/function/definition/basic.carbon b/toolchain/parser/testdata/function/definition/basic.carbon
index 47d6f6898e8c..2cd063314cbc 100644
--- a/toolchain/parser/testdata/function/definition/basic.carbon
+++ b/toolchain/parser/testdata/function/definition/basic.carbon
@@ -2,8 +2,8 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{carbon} dump parse-tree %s | %{FileCheck-strict} %s
-// AUTOUPDATE: %{carbon} dump parse-tree %s
+// AUTOUPDATE
+// RUN: %{carbon-run-parser}
 // CHECK:STDOUT: [
 // CHECK:STDOUT: {node_index: 5, kind: 'FunctionDeclaration', text: 'fn', subtree_size: 6, children: [
 // CHECK:STDOUT:   {node_index: 0, kind: 'DeclaredName', text: 'F'},
diff --git a/toolchain/parser/testdata/function/definition/identifier_in_statements.carbon b/toolchain/parser/testdata/function/definition/fail_identifier_in_statements.carbon
similarity index 85%
rename from toolchain/parser/testdata/function/definition/identifier_in_statements.carbon
rename to toolchain/parser/testdata/function/definition/fail_identifier_in_statements.carbon
index cb45aa48c59d..27818a2d4b8f 100644
--- a/toolchain/parser/testdata/function/definition/identifier_in_statements.carbon
+++ b/toolchain/parser/testdata/function/definition/fail_identifier_in_statements.carbon
@@ -2,8 +2,8 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{carbon} dump parse-tree %s | %{FileCheck-strict} %s
-// AUTOUPDATE: %{carbon} dump parse-tree %s
+// AUTOUPDATE
+// RUN: %{not} %{carbon-run-parser}
 // CHECK:STDOUT: [
 // CHECK:STDOUT: {node_index: 6, kind: 'FunctionDeclaration', text: 'fn', subtree_size: 7, children: [
 // CHECK:STDOUT:   {node_index: 0, kind: 'DeclaredName', text: 'F'},
@@ -19,5 +19,5 @@ fn F() {
   // Note: this might become valid depending on the expression syntax. This test
   // shouldn't be taken as a sign it should remain invalid.
   bar
-// CHECK:STDERR: {{.*}}/toolchain/parser/testdata/function/definition/identifier_in_statements.carbon:[[@LINE+1]]:1: Expected `;` after expression.
+// CHECK:STDERR: {{.*}}/toolchain/parser/testdata/function/definition/fail_identifier_in_statements.carbon:[[@LINE+1]]:1: Expected `;` after expression.
 }
diff --git a/toolchain/parser/testdata/function/definition/with_params.carbon b/toolchain/parser/testdata/function/definition/with_params.carbon
index 57d6ff34a3ce..e310d9cad081 100644
--- a/toolchain/parser/testdata/function/definition/with_params.carbon
+++ b/toolchain/parser/testdata/function/definition/with_params.carbon
@@ -2,8 +2,8 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{carbon} dump parse-tree %s | %{FileCheck-strict} %s
-// AUTOUPDATE: %{carbon} dump parse-tree %s
+// AUTOUPDATE
+// RUN: %{carbon-run-parser}
 // CHECK:STDOUT: [
 // CHECK:STDOUT: {node_index: 21, kind: 'FunctionDeclaration', text: 'fn', subtree_size: 22, children: [
 // CHECK:STDOUT:   {node_index: 0, kind: 'DeclaredName', text: 'foo'},
diff --git a/toolchain/parser/testdata/function/definition/with_return_type.carbon b/toolchain/parser/testdata/function/definition/with_return_type.carbon
index 627fe8023ab8..71480193c9ae 100644
--- a/toolchain/parser/testdata/function/definition/with_return_type.carbon
+++ b/toolchain/parser/testdata/function/definition/with_return_type.carbon
@@ -2,8 +2,8 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{carbon} dump parse-tree %s | %{FileCheck-strict} %s
-// AUTOUPDATE: %{carbon} dump parse-tree %s
+// AUTOUPDATE
+// RUN: %{carbon-run-parser}
 // CHECK:STDOUT: [
 // CHECK:STDOUT: {node_index: 10, kind: 'FunctionDeclaration', text: 'fn', subtree_size: 11, children: [
 // CHECK:STDOUT:   {node_index: 0, kind: 'DeclaredName', text: 'foo'},
diff --git a/toolchain/parser/testdata/if/basic.carbon b/toolchain/parser/testdata/if/basic.carbon
index c11f7b8cfd01..fe40ac995f86 100644
--- a/toolchain/parser/testdata/if/basic.carbon
+++ b/toolchain/parser/testdata/if/basic.carbon
@@ -2,8 +2,8 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{carbon} dump parse-tree %s | %{FileCheck-strict} %s
-// AUTOUPDATE: %{carbon} dump parse-tree %s
+// AUTOUPDATE
+// RUN: %{carbon-run-parser}
 // CHECK:STDOUT: [
 // CHECK:STDOUT: {node_index: 25, kind: 'FunctionDeclaration', text: 'fn', subtree_size: 26, children: [
 // CHECK:STDOUT:   {node_index: 0, kind: 'DeclaredName', text: 'F'},
diff --git a/toolchain/parser/testdata/if/else.carbon b/toolchain/parser/testdata/if/else.carbon
index 92cb870f71ea..d11507a63585 100644
--- a/toolchain/parser/testdata/if/else.carbon
+++ b/toolchain/parser/testdata/if/else.carbon
@@ -2,8 +2,8 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{carbon} dump parse-tree %s | %{FileCheck-strict} %s
-// AUTOUPDATE: %{carbon} dump parse-tree %s
+// AUTOUPDATE
+// RUN: %{carbon-run-parser}
 // CHECK:STDOUT: [
 // CHECK:STDOUT: {node_index: 60, kind: 'FunctionDeclaration', text: 'fn', subtree_size: 61, children: [
 // CHECK:STDOUT:   {node_index: 0, kind: 'DeclaredName', text: 'F'},
diff --git a/toolchain/parser/testdata/if/else_unbraced.carbon b/toolchain/parser/testdata/if/else_unbraced.carbon
index 9b8d417fbff2..a3970a016944 100644
--- a/toolchain/parser/testdata/if/else_unbraced.carbon
+++ b/toolchain/parser/testdata/if/else_unbraced.carbon
@@ -2,8 +2,8 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{carbon} dump parse-tree %s | %{FileCheck-strict} %s
-// AUTOUPDATE: %{carbon} dump parse-tree %s
+// AUTOUPDATE
+// RUN: %{carbon-run-parser}
 // CHECK:STDOUT: [
 // CHECK:STDOUT: {node_index: 52, kind: 'FunctionDeclaration', text: 'fn', subtree_size: 53, children: [
 // CHECK:STDOUT:   {node_index: 0, kind: 'DeclaredName', text: 'F'},
diff --git a/toolchain/parser/testdata/if/errors.carbon b/toolchain/parser/testdata/if/fail_errors.carbon
similarity index 80%
rename from toolchain/parser/testdata/if/errors.carbon
rename to toolchain/parser/testdata/if/fail_errors.carbon
index b66a04a84555..9acd6cedcd07 100644
--- a/toolchain/parser/testdata/if/errors.carbon
+++ b/toolchain/parser/testdata/if/fail_errors.carbon
@@ -2,8 +2,8 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{carbon} dump parse-tree %s | %{FileCheck-strict} %s
-// AUTOUPDATE: %{carbon} dump parse-tree %s
+// AUTOUPDATE
+// RUN: %{not} %{carbon-run-parser}
 // CHECK:STDOUT: [
 // CHECK:STDOUT: {node_index: 24, kind: 'FunctionDeclaration', text: 'fn', subtree_size: 25, children: [
 // CHECK:STDOUT:   {node_index: 0, kind: 'DeclaredName', text: 'F'},
@@ -34,13 +34,13 @@
 // CHECK:STDOUT: ]
 
 fn F() {
-  // CHECK:STDERR: {{.*}}/toolchain/parser/testdata/if/errors.carbon:[[@LINE+1]]:6: Expected `(` after `if`.
+  // CHECK:STDERR: {{.*}}/toolchain/parser/testdata/if/fail_errors.carbon:[[@LINE+1]]:6: Expected `(` after `if`.
   if a {}
-  // CHECK:STDERR: {{.*}}/toolchain/parser/testdata/if/errors.carbon:[[@LINE+1]]:7: Expected expression.
+  // CHECK:STDERR: {{.*}}/toolchain/parser/testdata/if/fail_errors.carbon:[[@LINE+1]]:7: Expected expression.
   if () {}
-  // CHECK:STDERR: {{.*}}/toolchain/parser/testdata/if/errors.carbon:[[@LINE+1]]:9: Unexpected tokens before `)`.
+  // CHECK:STDERR: {{.*}}/toolchain/parser/testdata/if/fail_errors.carbon:[[@LINE+1]]:9: Unexpected tokens before `)`.
   if (b c) {}
   if (d)
-// CHECK:STDERR: {{.*}}/toolchain/parser/testdata/if/errors.carbon:[[@LINE+2]]:1: Expected braced code block.
-// CHECK:STDERR: {{.*}}/toolchain/parser/testdata/if/errors.carbon:[[@LINE+1]]:1: Expected expression.
+// CHECK:STDERR: {{.*}}/toolchain/parser/testdata/if/fail_errors.carbon:[[@LINE+2]]:1: Expected braced code block.
+// CHECK:STDERR: {{.*}}/toolchain/parser/testdata/if/fail_errors.carbon:[[@LINE+1]]:1: Expected expression.
 }
diff --git a/toolchain/parser/testdata/if/unbraced.carbon b/toolchain/parser/testdata/if/unbraced.carbon
index 27ec23bdd5a6..12698852827a 100644
--- a/toolchain/parser/testdata/if/unbraced.carbon
+++ b/toolchain/parser/testdata/if/unbraced.carbon
@@ -3,8 +3,8 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: This should have an error.
-// RUN: %{carbon} dump parse-tree %s | %{FileCheck-strict} %s
-// AUTOUPDATE: %{carbon} dump parse-tree %s
+// AUTOUPDATE
+// RUN: %{carbon-run-parser}
 // CHECK:STDOUT: [
 // CHECK:STDOUT: {node_index: 19, kind: 'FunctionDeclaration', text: 'fn', subtree_size: 20, children: [
 // CHECK:STDOUT:   {node_index: 0, kind: 'DeclaredName', text: 'F'},
diff --git a/toolchain/parser/testdata/operators/associative.carbon b/toolchain/parser/testdata/operators/associative.carbon
index 588387181aff..a84fda725ab5 100644
--- a/toolchain/parser/testdata/operators/associative.carbon
+++ b/toolchain/parser/testdata/operators/associative.carbon
@@ -2,8 +2,8 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{carbon} dump parse-tree %s | %{FileCheck-strict} %s
-// AUTOUPDATE: %{carbon} dump parse-tree %s
+// AUTOUPDATE
+// RUN: %{carbon-run-parser}
 // CHECK:STDOUT: [
 // CHECK:STDOUT: {node_index: 11, kind: 'FunctionDeclaration', text: 'fn', subtree_size: 12, children: [
 // CHECK:STDOUT:   {node_index: 0, kind: 'DeclaredName', text: 'F'},
diff --git a/toolchain/parser/testdata/operators/missing_precedence_and_or.carbon b/toolchain/parser/testdata/operators/fail_missing_precedence_and_or.carbon
similarity index 83%
rename from toolchain/parser/testdata/operators/missing_precedence_and_or.carbon
rename to toolchain/parser/testdata/operators/fail_missing_precedence_and_or.carbon
index 2297b44bb132..bfe852daa0a8 100644
--- a/toolchain/parser/testdata/operators/missing_precedence_and_or.carbon
+++ b/toolchain/parser/testdata/operators/fail_missing_precedence_and_or.carbon
@@ -2,8 +2,8 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{carbon} dump parse-tree %s | %{FileCheck-strict} %s
-// AUTOUPDATE: %{carbon} dump parse-tree %s
+// AUTOUPDATE
+// RUN: %{not} %{carbon-run-parser}
 // CHECK:STDOUT: [
 // CHECK:STDOUT: {node_index: 11, kind: 'FunctionDeclaration', text: 'fn', subtree_size: 12, children: [
 // CHECK:STDOUT:   {node_index: 0, kind: 'DeclaredName', text: 'F'},
@@ -21,6 +21,6 @@
 // CHECK:STDOUT: ]
 
 fn F() {
-  // CHECK:STDERR: {{.*}}/toolchain/parser/testdata/operators/missing_precedence_and_or.carbon:[[@LINE+1]]:11: Parentheses are required to disambiguate operator precedence.
+  // CHECK:STDERR: {{.*}}/toolchain/parser/testdata/operators/fail_missing_precedence_and_or.carbon:[[@LINE+1]]:11: Parentheses are required to disambiguate operator precedence.
   a and b or c;
 }
diff --git a/toolchain/parser/testdata/operators/missing_precedence_or_and.carbon b/toolchain/parser/testdata/operators/fail_missing_precedence_or_and.carbon
similarity index 83%
rename from toolchain/parser/testdata/operators/missing_precedence_or_and.carbon
rename to toolchain/parser/testdata/operators/fail_missing_precedence_or_and.carbon
index 0f4c5172db9c..1e0daa6efedf 100644
--- a/toolchain/parser/testdata/operators/missing_precedence_or_and.carbon
+++ b/toolchain/parser/testdata/operators/fail_missing_precedence_or_and.carbon
@@ -2,8 +2,8 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{carbon} dump parse-tree %s | %{FileCheck-strict} %s
-// AUTOUPDATE: %{carbon} dump parse-tree %s
+// AUTOUPDATE
+// RUN: %{not} %{carbon-run-parser}
 // CHECK:STDOUT: [
 // CHECK:STDOUT: {node_index: 11, kind: 'FunctionDeclaration', text: 'fn', subtree_size: 12, children: [
 // CHECK:STDOUT:   {node_index: 0, kind: 'DeclaredName', text: 'F'},
@@ -21,6 +21,6 @@
 // CHECK:STDOUT: ]
 
 fn F() {
-  // CHECK:STDERR: {{.*}}/toolchain/parser/testdata/operators/missing_precedence_or_and.carbon:[[@LINE+1]]:10: Parentheses are required to disambiguate operator precedence.
+  // CHECK:STDERR: {{.*}}/toolchain/parser/testdata/operators/fail_missing_precedence_or_and.carbon:[[@LINE+1]]:10: Parentheses are required to disambiguate operator precedence.
   a or b and c;
 }
diff --git a/toolchain/parser/testdata/operators/variety.carbon b/toolchain/parser/testdata/operators/fail_variety.carbon
similarity index 80%
rename from toolchain/parser/testdata/operators/variety.carbon
rename to toolchain/parser/testdata/operators/fail_variety.carbon
index 821a057f18fa..f4868f00e9f5 100644
--- a/toolchain/parser/testdata/operators/variety.carbon
+++ b/toolchain/parser/testdata/operators/fail_variety.carbon
@@ -2,8 +2,8 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{not} %{carbon} dump parse-tree %s | %{FileCheck-strict} %s
-// AUTOUPDATE: %{carbon} dump parse-tree %s
+// AUTOUPDATE
+// RUN: %{not} %{carbon-run-parser}
 // CHECK:STDOUT: [
 // CHECK:STDOUT: {node_index: 26, kind: 'FunctionDeclaration', text: 'fn', subtree_size: 27, children: [
 // CHECK:STDOUT:   {node_index: 0, kind: 'DeclaredName', text: 'F'},
@@ -36,9 +36,9 @@
 // CHECK:STDOUT: ]
 
 fn F() {
-  // CHECK:STDERR: {{.*}}/toolchain/parser/testdata/operators/variety.carbon:[[@LINE+4]]:29: Parentheses are required to disambiguate operator precedence.
-  // CHECK:STDERR: {{.*}}/toolchain/parser/testdata/operators/variety.carbon:[[@LINE+3]]:34: Parentheses are required to disambiguate operator precedence.
-  // CHECK:STDERR: {{.*}}/toolchain/parser/testdata/operators/variety.carbon:[[@LINE+2]]:38: Parentheses are required to disambiguate operator precedence.
-  // CHECK:STDERR: {{.*}}/toolchain/parser/testdata/operators/variety.carbon:[[@LINE+1]]:40: Parentheses are required to disambiguate operator precedence.
+  // CHECK:STDERR: {{.*}}/toolchain/parser/testdata/operators/fail_variety.carbon:[[@LINE+4]]:29: Parentheses are required to disambiguate operator precedence.
+  // CHECK:STDERR: {{.*}}/toolchain/parser/testdata/operators/fail_variety.carbon:[[@LINE+3]]:34: Parentheses are required to disambiguate operator precedence.
+  // CHECK:STDERR: {{.*}}/toolchain/parser/testdata/operators/fail_variety.carbon:[[@LINE+2]]:38: Parentheses are required to disambiguate operator precedence.
+  // CHECK:STDERR: {{.*}}/toolchain/parser/testdata/operators/fail_variety.carbon:[[@LINE+1]]:40: Parentheses are required to disambiguate operator precedence.
   n = a * b + c * d = d * d << e & f - not g;
 }
diff --git a/toolchain/parser/testdata/operators/fixity.carbon b/toolchain/parser/testdata/operators/fixity.carbon
index c24d9e2696d6..434f10f69859 100644
--- a/toolchain/parser/testdata/operators/fixity.carbon
+++ b/toolchain/parser/testdata/operators/fixity.carbon
@@ -2,8 +2,8 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{carbon} dump parse-tree %s | %{FileCheck-strict} %s
-// AUTOUPDATE: %{carbon} dump parse-tree %s
+// AUTOUPDATE
+// RUN: %{carbon-run-parser}
 // CHECK:STDOUT: [
 // CHECK:STDOUT: {node_index: 64, kind: 'FunctionDeclaration', text: 'fn', subtree_size: 65, children: [
 // CHECK:STDOUT:   {node_index: 0, kind: 'DeclaredName', text: 'F'},
diff --git a/toolchain/parser/testdata/operators/missing_precedence_not.carbon b/toolchain/parser/testdata/operators/missing_precedence_not.carbon
index 5ac08bc47952..37cf5c30d437 100644
--- a/toolchain/parser/testdata/operators/missing_precedence_not.carbon
+++ b/toolchain/parser/testdata/operators/missing_precedence_not.carbon
@@ -2,8 +2,8 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{carbon} dump parse-tree %s | %{FileCheck-strict} %s
-// AUTOUPDATE: %{carbon} dump parse-tree %s
+// AUTOUPDATE
+// RUN: %{carbon-run-parser}
 // CHECK:STDOUT: [
 // CHECK:STDOUT: {node_index: 14, kind: 'FunctionDeclaration', text: 'fn', subtree_size: 15, children: [
 // CHECK:STDOUT:   {node_index: 0, kind: 'DeclaredName', text: 'F'},
diff --git a/toolchain/parser/testdata/operators/postfix_unary.carbon b/toolchain/parser/testdata/operators/postfix_unary.carbon
index 11a3c9ff6f8f..d37cc99343e4 100644
--- a/toolchain/parser/testdata/operators/postfix_unary.carbon
+++ b/toolchain/parser/testdata/operators/postfix_unary.carbon
@@ -2,8 +2,8 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{carbon} dump parse-tree %s | %{FileCheck-strict} %s
-// AUTOUPDATE: %{carbon} dump parse-tree %s
+// AUTOUPDATE
+// RUN: %{carbon-run-parser}
 // CHECK:STDOUT: [
 // CHECK:STDOUT: {node_index: 9, kind: 'FunctionDeclaration', text: 'fn', subtree_size: 10, children: [
 // CHECK:STDOUT:   {node_index: 0, kind: 'DeclaredName', text: 'F'},
diff --git a/toolchain/parser/testdata/operators/prefix_unary.carbon b/toolchain/parser/testdata/operators/prefix_unary.carbon
index 921d86bd1d08..935d96e01e23 100644
--- a/toolchain/parser/testdata/operators/prefix_unary.carbon
+++ b/toolchain/parser/testdata/operators/prefix_unary.carbon
@@ -2,8 +2,8 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{carbon} dump parse-tree %s | %{FileCheck-strict} %s
-// AUTOUPDATE: %{carbon} dump parse-tree %s
+// AUTOUPDATE
+// RUN: %{carbon-run-parser}
 // CHECK:STDOUT: [
 // CHECK:STDOUT: {node_index: 9, kind: 'FunctionDeclaration', text: 'fn', subtree_size: 10, children: [
 // CHECK:STDOUT:   {node_index: 0, kind: 'DeclaredName', text: 'F'},
diff --git a/toolchain/parser/testdata/while/basic.carbon b/toolchain/parser/testdata/while/basic.carbon
index 6072ae8723d5..109751c9c1e3 100644
--- a/toolchain/parser/testdata/while/basic.carbon
+++ b/toolchain/parser/testdata/while/basic.carbon
@@ -2,8 +2,8 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{carbon} dump parse-tree %s | %{FileCheck-strict} %s
-// AUTOUPDATE: %{carbon} dump parse-tree %s
+// AUTOUPDATE
+// RUN: %{carbon-run-parser}
 // CHECK:STDOUT: [
 // CHECK:STDOUT: {node_index: 27, kind: 'FunctionDeclaration', text: 'fn', subtree_size: 28, children: [
 // CHECK:STDOUT:   {node_index: 0, kind: 'DeclaredName', text: 'F'},
diff --git a/toolchain/parser/testdata/while/unbraced.carbon b/toolchain/parser/testdata/while/unbraced.carbon
index e9b19cb9de17..482f9d6f8678 100644
--- a/toolchain/parser/testdata/while/unbraced.carbon
+++ b/toolchain/parser/testdata/while/unbraced.carbon
@@ -3,8 +3,8 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: This should have an error.
-// RUN: %{carbon} dump parse-tree %s | %{FileCheck-strict} %s
-// AUTOUPDATE: %{carbon} dump parse-tree %s
+// AUTOUPDATE
+// RUN: %{carbon-run-parser}
 // CHECK:STDOUT: [
 // CHECK:STDOUT: {node_index: 11, kind: 'FunctionDeclaration', text: 'fn', subtree_size: 12, children: [
 // CHECK:STDOUT:   {node_index: 0, kind: 'DeclaredName', text: 'F'},
diff --git a/toolchain/semantics/lit_autoupdate.py b/toolchain/semantics/lit_autoupdate.py
index 98f09e4b988c..51bd4078a745 100755
--- a/toolchain/semantics/lit_autoupdate.py
+++ b/toolchain/semantics/lit_autoupdate.py
@@ -14,8 +14,8 @@ from pathlib import Path
 
 
 def main() -> None:
-    # Calls the main script with explorer settings. This uses execv in order to
-    # avoid Python import behaviors.
+    # Calls the main script using execv in order to avoid Python import
+    # behaviors.
     this_py = Path(__file__).resolve()
     actual_py = this_py.parent.parent.parent.joinpath(
         "bazel", "testing", "lit_autoupdate_base.py"
@@ -23,14 +23,14 @@ def main() -> None:
     args = [
         sys.argv[0],
         # Flags to configure for explorer testing.
-        "--build_target",
-        "//toolchain/driver:carbon",
+        "--tool=carbon",
+        "--autoupdate_arg=dump",
+        "--autoupdate_arg=semantics-ir",
         # TODO: This should eventually have lines in output, but it doesn't
         # right now.
-        "--line_number_pattern",
-        "UNUSED",
-        "--testdata",
-        "toolchain/semantics/testdata",
+        "--line_number_pattern=UNUSED",
+        "--lit_run=%{carbon-run-semantics}",
+        "--testdata=toolchain/semantics/testdata",
     ] + sys.argv[1:]
     os.execv(actual_py, args)
 
diff --git a/toolchain/semantics/testdata/empty.carbon b/toolchain/semantics/testdata/empty.carbon
index 004cd8679fb8..2fe65fbcbd4d 100644
--- a/toolchain/semantics/testdata/empty.carbon
+++ b/toolchain/semantics/testdata/empty.carbon
@@ -2,7 +2,7 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{carbon} dump semantics-ir %s | %{FileCheck-strict} %s
-// AUTOUPDATE: %{carbon} dump semantics-ir %s
+// AUTOUPDATE
+// RUN: %{carbon-run-semantics}
 // CHECK:STDOUT: {
 // CHECK:STDOUT: }
diff --git a/toolchain/semantics/testdata/function/basic.carbon b/toolchain/semantics/testdata/function/basic.carbon
index 93f60b925b55..2ece5b6cdbae 100644
--- a/toolchain/semantics/testdata/function/basic.carbon
+++ b/toolchain/semantics/testdata/function/basic.carbon
@@ -2,8 +2,8 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{carbon} dump semantics-ir %s | %{FileCheck-strict} %s
-// AUTOUPDATE: %{carbon} dump semantics-ir %s
+// AUTOUPDATE
+// RUN: %{carbon-run-semantics}
 // CHECK:STDOUT: {
 // CHECK:STDOUT:   Function(
 // CHECK:STDOUT:       %0,
diff --git a/toolchain/semantics/testdata/function/order.carbon b/toolchain/semantics/testdata/function/order.carbon
index c8bbd32d227c..feb4ec1b910e 100644
--- a/toolchain/semantics/testdata/function/order.carbon
+++ b/toolchain/semantics/testdata/function/order.carbon
@@ -2,8 +2,8 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{carbon} dump semantics-ir %s | %{FileCheck-strict} %s
-// AUTOUPDATE: %{carbon} dump semantics-ir %s
+// AUTOUPDATE
+// RUN: %{carbon-run-semantics}
 // CHECK:STDOUT: {
 // CHECK:STDOUT:   Function(
 // CHECK:STDOUT:       %2,
diff --git a/toolchain/semantics/testdata/return/binary_op.carbon b/toolchain/semantics/testdata/return/binary_op.carbon
index 246ac438fce9..9f89e675cfc5 100644
--- a/toolchain/semantics/testdata/return/binary_op.carbon
+++ b/toolchain/semantics/testdata/return/binary_op.carbon
@@ -2,8 +2,8 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{carbon} dump semantics-ir %s | %{FileCheck-strict} %s
-// AUTOUPDATE: %{carbon} dump semantics-ir %s
+// AUTOUPDATE
+// RUN: %{carbon-run-semantics}
 // CHECK:STDOUT: {
 // CHECK:STDOUT:   Function(
 // CHECK:STDOUT:       %0,
diff --git a/toolchain/semantics/testdata/return/literal.carbon b/toolchain/semantics/testdata/return/literal.carbon
index 89caf13fe9d8..8a09ed299c31 100644
--- a/toolchain/semantics/testdata/return/literal.carbon
+++ b/toolchain/semantics/testdata/return/literal.carbon
@@ -2,8 +2,8 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{carbon} dump semantics-ir %s | %{FileCheck-strict} %s
-// AUTOUPDATE: %{carbon} dump semantics-ir %s
+// AUTOUPDATE
+// RUN: %{carbon-run-semantics}
 // CHECK:STDOUT: {
 // CHECK:STDOUT:   Function(
 // CHECK:STDOUT:       %0,
diff --git a/toolchain/semantics/testdata/return/trivial.carbon b/toolchain/semantics/testdata/return/trivial.carbon
index 22bcbeff1609..08ac417593c5 100644
--- a/toolchain/semantics/testdata/return/trivial.carbon
+++ b/toolchain/semantics/testdata/return/trivial.carbon
@@ -2,8 +2,8 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// RUN: %{carbon} dump semantics-ir %s | %{FileCheck-strict} %s
-// AUTOUPDATE: %{carbon} dump semantics-ir %s
+// AUTOUPDATE
+// RUN: %{carbon-run-semantics}
 // CHECK:STDOUT: {
 // CHECK:STDOUT:   Function(
 // CHECK:STDOUT:       %0,