The main motivation for this is to get python loads in using the
`native-py` lint fix. However, enabling that made me wonder, maybe we
should fix in general?
`native-cc` is delayed, but not wholly cancelled (and `native-py`
picking up might indicate `native-cc` won't be too far behind). There's
also some automated fixes for `.append` and dict sorting -- this felt
okay to me, maybe not something to eagerly add but probably not worth
stopping buildifier from fixing (I've noticed the warnings in the past
and had been ignoring them).
Running everything does mean that load orders are sorted automatically
now, which I think is a positive. Most generally, I think these fixes
aren't _harmful_, and having them done automatically seems beneficial:
my biggest concern about `native-py` and `native-cc` was actually that
regressions wouldn't be caught, but this addresses that issue
automatically.
I'm integrating absl flag support with a few thoughts here...
1. It simplifies the handling of files in file_test.
- Removes the need for a separate subset target.
3. Looking forward, I'm planning to add a flag to allow for autoupdate
of golden files.
4. In explorer, there's been confusion about having file_test run tests
"twice" so hopefully it's clearer when it's a separate target with a
different flag on the target.
This is really part of #2811, but is extracted out to allow a little review in parallelism because #2811 expects #2813. Getting this in will allow migration of toolchain tests, whereas #2811 is focused on explorer tests. For explorer test timing information, see #2811.
The syntax being used for matching deliberately mirrors the `FileCheck` setup, partly for compatibility if something changes, partly so there's nothing new to learn, partly so that we don't need to build more test updating.
Individual tests look like:
```
[ RUN ] ParseAndExecuteTestFile.explorer/parse_and_execute/testdata/assert/convert.carbon
To test this file alone, run:
bazel test //explorer/parse_and_execute:file_test.subset --test_arg=explorer/parse_and_execute/testdata/assert/convert.carbon
[ OK ] ParseAndExecuteTestFile.explorer/parse_and_execute/testdata/assert/convert.carbon (202 ms)
```
The printed command line is intended to assist developers in debugging a single test, particularly when sharding the main test. The use of a single `.subset` target means the total number of targets is constant even as the number of test files increases, which may be important for some `bazel` execution environments. I plan to make similar changes to the `glob_sh_run` implementation so that we have consistent setups, i.e. that we no longer create target-per-file scaling risks.
This uses `native_test` to share the test binary, avoiding re-linking if files are individually run.
Investigation did reveal a mistake where STDOUT/STDERR wasn't prefixed on empty output lines; this PR fixes that mistake, so that output is fully covered.
Co-authored-by: Chandler Carruth <chandlerc@gmail.com>
Jon Ross-Perkins
