commit d5945ed2158d1c7a205f278c89520aa4da497442
author Alex Martani <alexandre.martani@benchling.com> Wed Mar 20 19:10:21 2024 -0700
committer GitHub <noreply@github.com> Thu Mar 21 02:10:21 2024 +0000
tree 7154af1fdc8c1d6e811693a274c308ce55c8de5a
parent e86252ffd6d1a1bf32ae99933acc5ab49b78ec1e

fix(gazelle): Do not create invalid py_test rules in `project` generation mode (#1809)

Since https://github.com/bazelbuild/rules_python/pull/1538, when using
`gazelle:python_generation_mode project`, a `py_test` rule is created
even when there are no test files in the project.
fb673ee47b3268a65a18a154edd574b6509c38c7 (first commit on the PR branch)
reproduces this issue - it shows that a `py_test` rule is created even
when there is no test entrypoint file (`__test__.py`) nor any test file
in the entire project. Additionally, test rules created on `project` or
`package` generation mode will always set `main = "__test__.py"`, even
when that file doesn't exist.

This PR fixes it by only generating a `py_test` rule if it can find some
test file - either an explicit `__test__.py`, or any other file prefixed
with `test_` or suffixed with `_test.py`. It also changes the generated
test rule to only add `main = "__test__.py"` if there is an actual
`__test__.py` file. Note that, in the case where a `__test__.py` file
doesn't exist, the generated `py_test` rule is likely invalid as-is due
to the lack of `main`; this can be fixed by mapping to some other
`py_test` implementation, and I believe the new behavior makes more
sense than pointing `main` to a non-existing file.

It may be useful to review per-commit (all tests pass on each commit):
- First commit reproduces the issue;
- Second commit fixes the issue and the corresponding tests;
- Third commit adds additional test cases.