CI: Check and fix missing __init__.py with flake8-no-pep420

[intgr]

Related issues

As suggested in #1460 (comment)

[adamchainz]

Ha, I was just working on this, and adding .pyi support to the plugin: adamchainz/flake8-no-pep420#183

[intgr]

ISTM tests isn't really a package, so I wouldn't add __init__.py there?

Also I renamed django-stubs/contrib/postgres/forms/jsonb.py to .pyi, this was a mistake clearly.

[sobolevn]

The next step is to "steal" some checks from typeshed to catch .py file extensions 😆

See https://github.com/python/typeshed/blob/main/tests/check_consistent.py

@adamchainz you made so many awesome things, thank you 👍

[adamchainz]

ISTM tests isn't really a package, so I wouldn't add __init__.py there?

Eh, I normally make my tests folder a package, but it's a bit different here since all the tests are yaml files.

Also I renamed django-stubs/contrib/postgres/forms/jsonb.py to .pyi, this was a mistake clearly.

Right you are!

@adamchainz you made so many awesome things, thank you 👍

Just solving problems I encounter, like yourself! 🫡

[intgr]

Eh, I normally make my tests folder a package, but it's a bit different here since all the tests are yaml files.

Actually you're right. It makes sense that they're a packge, because a test module may want to import code from other tests modules.

[intgr]

Hrm, adding __init__.py to tests causes errors in CI:

ImportError while importing test module '/home/runner/work/django-stubs/django-stubs/django_stubs_ext/tests/test_aliases.py'.
Hint: make sure your test modules/packages have valid Python names.
Traceback:
/opt/hostedtoolcache/Python/3.9.16/x64/lib/python3.9/importlib/__init__.py:127: in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
E   ModuleNotFoundError: No module named 'tests.test_aliases'

Looks like it causes tests and django_stubs_ext/tests to conflict.

Are there any solutions or should I just revert these __init__.py? I have no strong opinion on this.

[sobolevn]

I never use __init__.py in tests.