Static type checking with mypy doesn't work

[TheAfroOfDoom]

Went down a rabbit-hole with the following plugins trying to enable mypy so we can have static type checking on the backend API.

• mypy_django_plugin
• mypy_drf_plugin
• local plugin supporting django-configurations via this thread

I think the combination of django-configurations and django-restframework are screwing up mypy's plugin system.

Ultimately I got blocked at this issue and found no way around it: typeddjango/django-stubs#461. So I'm dropping static typing via mypy for now.

---

I had the following configurations setup to get to the point of getting this error whenever I tried to import mypy_django_plugin.main:

backend/mypy.ini

[mypy]
plugins =
    ./configurations_mypy_django_plugin.py, mypy_drf_plugin.main

show_error_codes = True

[mypy.plugins.django-stubs]
django_settings_module = "api.config"

[mypy-api.*.migrations.*]
# Django migrations should not produce any errors:
ignore_errors = true

backend/configurations_mypy_django_plugin.py

# https://github.com/typeddjango/django-stubs/pull/180#issuecomment-820062352
# configurations_mypy_django_plugin.py
import os
from configurations.importer import install
from mypy.version import __version__

from mypy_django_plugin import main

# from mypy_drf_plugin import main


def plugin(version):
    os.environ.setdefault("DJANGO_SETTINGS_MODULE", "api.config")
    os.environ.setdefault("DJANGO_CONFIGURATION", "Local")
    install()
    return main.plugin(version)

Running py -3.9 -m mypy api --show-traceback gives this error message:

api\users\models.py:7: error: Skipping analyzing "django.dispatch": module is installed, but missing library stubs or py.typed marker  [import]
C:\Python39\lib\site-packages\rest_framework-stubs\authtoken\models.pyi:12: error: INTERNAL ERROR -- Please try using mypy master on GitHub:
https://mypy.readthedocs.io/en/stable/common_issues.html#using-a-development-mypy-build
Please report a bug at https://github.com/python/mypy/issues
version: 0.961
Traceback (most recent call last):
  File "C:\Python39\lib\runpy.py", line 197, in _run_module_as_main
    return _run_code(code, main_globals, None,
  File "C:\Python39\lib\runpy.py", line 87, in _run_code
    exec(code, run_globals)
  File "mypy\semanal.py", line 5350, in accept
  File "mypy\nodes.py", line 1028, in accept
  File "mypy\semanal.py", line 1123, in visit_class_def
  File "mypy\semanal.py", line 1203, in analyze_class
  File "mypy\semanal.py", line 1212, in analyze_class_body_common
  File "mypy\semanal.py", line 1257, in apply_class_plugin_hooks
  File "C:\Python39\lib\site-packages\mypy_django_plugin\main.py", line 48, in transform_model_class
    process_model_class(ctx, django_context)
  File "C:\Python39\lib\site-packages\mypy_django_plugin\transformers\models.py", line 514, in process_model_class
    initializer_cls(ctx, django_context).run()
  File "C:\Python39\lib\site-packages\mypy_django_plugin\transformers\models.py", line 70, in run
    self.run_with_model_cls(model_cls)
  File "C:\Python39\lib\site-packages\mypy_django_plugin\transformers\models.py", line 286, in run_with_model_cls
    assert (
AssertionError: Type info for Django's django.db.models.manager.Manager missing
C:\Python39\lib\site-packages\rest_framework-stubs\authtoken\models.pyi:12: : note: use --pdb to drop into pdb

I have not yet tried using the latest developer build as suggested by the error message (Please try using mypy master on GitHub: https://mypy.readthedocs.io/en/stable/common_issues.html#using-a-development-mypy-build).