.annotate(...) does not seem to work with reverse-related foreign key lookupu

[asottile-sentry]

Bug report

wrote a little testcase -- will see if I can figure out a quick fix for it

- case: test_annotate_reverse_related
  main: |
    from myapp.models import MB
    from django.db.models import Count

    o = MB.objects.annotate(Count("mas")).get()
    reveal_type(o.mas__count)  # N: Revealed type is "builtins.int"
  installed_apps:
    - myapp
  files:
    - path: myapp/__init__.py
    - path: myapp/models.py
      content: |
        from django.db import models

        class MA(models.Model):
            mb = models.ForeignKey("MB", related_name="mas", on_delete=models.CASCADE)

        class MB(models.Model): pass

What's wrong

_______________________________________ test_annotate_reverse_related _______________________________________
/Users/asottile/workspace/sentry-forked-django-stubs/tests/typecheck/managers/querysets/test_annotate.yml:405: 
E   pytest_mypy_plugins.utils.TypecheckAssertionError: Invalid output: 
E   Actual:
E     main:5: error: "MB" has no attribute "mas__count"  [attr-defined] (diff)
E     main:5: note: Revealed type is "Any"          (diff)
E   Expected:
E     main:5: note: Revealed type is "builtins.int" (diff)
E   Alignment of first line difference:
E     E: main:5: note: Revealed type is "builtins.int"
E     A: main:5: error: "MB" has no attribute "mas__count"  [attr-defined]
E                ^

How is that should be

should resolve correctly

System information

• OS:
• python version: 3.12.6
• django version: 5.1.1
• mypy version: 1.11.
• django-stubs version: 5.1.0
• django-stubs-ext version: 5.1.0

[asottile-sentry]

ah I see from reading the code that it just doesn't support non-named arguments. there's a few tests which are passing just due to luck it seems (since they also use non-named arguments assuming they'll produce a WithAnnotations)

what's a little weird is this seems to have worked before django-stubs 5.1.0 -- but I suspect that was due to the old implementation being buggy

[asottile-sentry]

actually just one test:

django-stubs/tests/typecheck/managers/querysets/test_annotate.yml

Line 177 in ffcebb3

qs = User.objects.annotate(Count('id'))