Switch executable semantics to use ErrorBuilder directly and relocate macros (#1184)

common/error_test.cpp

@@ -49,5 +49,53 @@ TEST(ErrorTest, IndirectErrorOrSuccess) {
   EXPECT_TRUE(IndirectErrorOrSuccessTest().ok());
 }
 
+TEST(ErrorTest, ReturnIfErrorNoError) {
+  auto result = []() -> ErrorOr<Success> {
+    RETURN_IF_ERROR(ErrorOr<Success>(Success()));
+    RETURN_IF_ERROR(ErrorOr<Success>(Success()));
+    return Success();
+  }();
+  EXPECT_TRUE(result.ok());
+}
+
+TEST(ErrorTest, ReturnIfErrorHasError) {
+  auto result = []() -> ErrorOr<Success> {
+    RETURN_IF_ERROR(ErrorOr<Success>(Success()));
+    RETURN_IF_ERROR(ErrorOr<Success>(Error("error")));
+    return Success();
+  }();
+  ASSERT_FALSE(result.ok());
+  EXPECT_EQ(result.error().message(), "error");
+}
+
+TEST(ErrorTest, AssignOrReturnNoError) {
+  auto result = []() -> ErrorOr<int> {
+    ASSIGN_OR_RETURN(int a, ErrorOr<int>(1));
+    ASSIGN_OR_RETURN(const int b, ErrorOr<int>(2));
+    int c = 0;
+    ASSIGN_OR_RETURN(c, ErrorOr<int>(3));
+    return a + b + c;
+  }();
+  ASSERT_TRUE(result.ok());
+  EXPECT_EQ(6, *result);
+}
+
+TEST(ErrorTest, AssignOrReturnHasDirectError) {
+  auto result = []() -> ErrorOr<int> {
+    RETURN_IF_ERROR(ErrorOr<int>(Error("error")));
+    return 0;
+  }();
+  ASSERT_FALSE(result.ok());
+}
+
+TEST(ErrorTest, AssignOrReturnHasErrorInExpected) {
+  auto result = []() -> ErrorOr<int> {
+    ASSIGN_OR_RETURN(int a, ErrorOr<int>(Error("error")));
+    return a;
+  }();
+  ASSERT_FALSE(result.ok());
+  EXPECT_EQ(result.error().message(), "error");
+}
+
 }  // namespace
 }  // namespace Carbon::Testing