Introduce flake8-pyi in pre-commit checks

[hoefling]

I have made things!

This is a PR similar to typeddjango/django-stubs#1253, only for rest_framework-stubs.

All statements that are unclear on how to proceed are marked with # noqa: in the code, with the exception of compat.pyi, which has additional rules turned off in setup.cfg.

There are some low-hanging fruits to fix, e.g.

djangorestframework-stubs/rest_framework-stubs/fields.pyi

Line 350 in 89f8925

max_whole_digits = Optional[int]

should obviously be

max_whole_digits: int | None

or

djangorestframework-stubs/rest_framework-stubs/routers.pyi

Line 60 in 89f8925

default_schema_renderers = None

which could be set to default_schema_renderers: None, or removed altogether.

[intgr]

I think None is the default value and should be removed.

You can type this as : Any for now.

[intgr]

But you/I can fix these in a follow-up just as well. Up to you.

[intgr]

To fix the tests, you need a small change in typecheck_tests.py:

--- a/scripts/typecheck_tests.py
+++ b/scripts/typecheck_tests.py
@@ -239,7 +239,7 @@ IGNORED_ERRORS = {
         'Argument "data" to "ValidationSerializer" has incompatible type "str"',
     ],
     "test_validation_error.py": [
-        'Argument "detail" to "ValidationError" has incompatible type "Tuple[str, str]"; expected "Union[str, List[Any], Dict[str, Any], None]"',  # noqa: E501
+        'Argument "detail" to "ValidationError" has incompatible type "Tuple[str, str]"; expected "Optional[Union[str, List[Any], Dict[str, Any]]]"',  # noqa: E501
     ],
     "test_validators.py": [
         'Argument "queryset" to "BaseUniqueForValidator" has incompatible type "object";'

[intgr]

Sorry, I merged another PR to master and there are merge conflicts now.

I'll defer any other .pyi changes until this is closed.

[intgr]

Once the conflicts are solved and typecheck_tests.py updated, I can merge this.

[hoefling]

@intgr sorry for the delay, could not finish the PR on Monday. And thank you for the hint for fixing the test error!

[hoefling]

Will amend the remaining issues shortly

[intgr]

There seems to be a missing import:

djangorestframework-stubs/djangorestframework-stubs/rest_framework-stubs/test.pyi:70: error: Name "Response" is not defined (diff)

[hoefling]

@intgr yep I didn't pay enough attention when rebasing 🤦‍♀️

[sobolevn]

Thank you! Very much appreciated.

[intgr]

Awesome.