Fix apps.get_model() return type

[yhoiseth]

Related issues

• Closes Too broad return value for apps.get_model() #304

[yhoiseth]

Troubleshooting notes

• All jobs pass except Typecheck Django 2.2 test suite with python 3.7

Reproduce locally

Done. (Everything below UNUSED IGNORES is present on master, as well.)

Try to fix

Union[Type[Any], Type[Model]] doesn't work, either… Weird, considering that Type[Any] works.

Two models are failing: SiteManager and Food. They both have attributes/methods that aren't present on Model. Considering that they are both models, I think it makes sense that the type hint Type[Model] is more correct than Type[Any]. But the test doesn't agree.

It's unclear to me why it works with 3.0 but not with 2.2.

Appending # type: ignore to the failing test lines works, but not sure whether that's a good idea. Also unsure what the repo situation with django-sources/ is.

Next steps

I don't have any more ideas for how to proceed.

[mkurnikov]

I think it requires plugin support, otherwise, it will create a bunch of false-positives everywhere.