Using the django.core.checks.register makes function untyped

[jaap3]

I'm experimenting with type annotations and chose a fairly simple project to add type annotations to (just a couple of additional Django checks). However I ran into the following:

What's wrong

from django.core.checks import register

@register("foo")
def check_foo_is_bar(app_configs: Apps, **kwargs: Any) -> List[Warning]:
    ...

Results in mypy complaining:

Untyped decorator makes function "check_foo_is_bar" untyped

How it should be

The register decorator is currently annotated as returning Any. If somehow it can be annotated as being essentially the same as CheckRegistry.register all would be well (I think). Is that possible?

System information

• python version: Python 3.8.12
• django version: 4.1
• mypy version: 0.961
• django-stubs version: 1.12.0
• django-stubs-ext version: 0.5.0

Additional information

It's possible to work around this by using the decorator as a function instead:

def check_foo_is_bar(app_configs: Apps, **kwargs: Any) -> List[Warning]:
    ...

register(check_foo_is_bar, "foo")

But it would be nice if the decorator worked as well.