feat: Support parsing pytest_plugins as a form of import.

[kayliespace]

feature request

Pytest does not utilize normal imports for fixtures, instead in your conftest.py or test file you can declare a pytest_plugins global, like so:

# To import foo.bar.baz and foo.bar.qux as pytest plugins that expose fixtures.
pytest_plugins = ["foo.bar.baz", "foo.bar.qux"]
# OR
pytest_plugins = ("foo.bar.baz", "foo.bar.qux")
# OR, to import only one item
pytest_plugins = "foo.bar.baz"
# No other formats are valid

This is, by pytest's standards, the intended way to import fixtures and extensions to the test engine, simply importing them is poorly supported and will not include transitive fixtures, nor properly rewrite asserts in the import.

pytest_plugins simply contains import paths and brings all fixtures and extensions in the import into scope.

Relevant Rules

Just the Gazelle plugin.

Description

This would be extending the Gazelle plugin to read pytest_plugins as a form of import, which should go in deps as normal.

Describe alternatives you've considered

Currently, we instead do this:

# gazelle:include_dep //tools/foo/tests:git_worktree,//tools/corporate_tool_utils/python/fixtures:put
pytest_plugins = ["tools.foo.tests.git_worktree", "tools.corporate_tool_utils.python.fixtures.put"]

This works fine, and is something we can lint for, but adds redundancy and can mismatch gazelle's preferred label for a dependency.