Getting "Cannot resolve keyword 'author' into field" after annotating with QS function

[torarvid]

Bug report

What's wrong

Not sure if this is django-stubs or mypy or what, but basically if I bump django-stubs from 5.2.2 to .3 or larger, I get mypy errors for keywords in filter() calls if the keyword is annotated inside of a function inside of a queryset method. I guess an example will illustrate better, so here goes:

from typing import Self

from django.db.models import CharField, Manager, Model, QuerySet


class BookQuerySet(QuerySet["Book"]):
    def annotate_author(self) -> Self:
        return self.annotate(author="blah")


class Book(Model):
    title: CharField[str, str] = CharField[str, str]()
    objects: Manager["Book"] = Manager["Book"].from_queryset(BookQuerySet)()


def foo() -> None:
    qs: BookQuerySet = Book.objects.all()
    qs.filter(foo="bar").count()  # Error 'misc'; as intended
    qs.annotate(foo=123).filter(foo=123).count()  # Ok; as intended
    qs.annotate_author().filter(author="blah").count()  # Error 'misc' <-- bug, IMO

When I run mypy on it, I get this:

❯ uv run mypy .
somesite/models.py:18: error: Cannot resolve keyword 'foo' into field. Choices are: id, title  [misc]
somesite/models.py:20: error: Cannot resolve keyword 'author' into field. Choices are: id, title  [misc]
Found 2 errors in 1 file (checked 7 source files)

So the line 18 error is expected in my head, since 'foo' is not a prop or an annotation. Line 19 does an explicit annotation inline, so mypy is happy there. But on 20, the .annotate_author call returns Self. To me it is doing "the same as the annotation on line 19, but wrapped in a queryset method".

How is that should be

I expected:

❯ uv run mypy .
somesite/models.py:18: error: Cannot resolve keyword 'foo' into field. Choices are: id, title  [misc]
Found 1 errors in 1 file (checked 7 source files)

As mentioned in the intro, I'm not sure if this is just a mypy limitation, but since I noticed it after django-stubs 5.2.3+, I'm reporting it here 🤷🏼‍♂️

System information

• OS:
• python version: 3.13.7
• django version: 5.2.8
• mypy version: 1.18.2
• django-stubs version: 5.2.7
• django-stubs-ext version: 5.2.7

[UnknownPlatypus]

This is another symptom of #2602

mypy is technically correct here because in this code, the information about the .annotate() is lost with the return -> Self, it would need something like -> BookQuerySet[WithAnnotations[Book, TypedDict(author: str)]] to retain the information.

Solving #2681 might fix your case.

(Also you started getting errors with version 5.2.3 because of #2784. Prior to that, filter/exclude on custom QuerySet were just not checked at all)