Add strict_settings option, allow runtime fallbacks for custom settings

[sobolevn]

This PR adds a new setting to our plugin called strict_settings.
When set to True (the default), it raises for any statically unknown setting value.

But, when set to False, it checks for the runtime setting value and if it is present, it returns Any in all cases.

This will change will make it possible to use django-stubs with django-split-settings (which I maintain and use for all my projects) and similar tools like django-configurations.

After #1163 it was very hard to use settings in dynamic workflows.

Closes #1410
Closes #1276
Closes #417

[intgr]

Although there are just 2 settings for now, I would prefer it if all django-stubs settings were documented in one place. Maybe add another README section for settings and then link to it from here?

[sobolevn]

Yes, we can do this later. Good idea 👍

[intgr]

When I try to run this in one of my projects, I get the following error. Haven't investigated at all.

mypy 1.4.0 (compiled: yes)
Traceback (most recent call last):
  File ".../bin/mypy", line 8, in <module>
Error constructing plugin instance of NewSemanalDRFPlugin

    sys.exit(console_entry())
             ^^^^^^^^^^^^^^^
  File ".../lib/python3.11/site-packages/mypy/__main__.py", line 15, in console_entry
    main()
  File "mypy/main.py", line 95, in main
  ...
  File "mypy/build.py", line 484, in load_plugins_from_config
  File ".../lib/python3.11/site-packages/mypy_drf_plugin/main.py", line 26, in __init__
    self.django_context = DjangoContext(django_settings_module)
                          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File ".../lib/python3.11/site-packages/mypy_django_plugin/django/context.py", line 85, in __init__
    apps, settings = initialize_django(self.plugin_config.django_settings_module)
                                       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
AttributeError: 'str' object has no attribute 'django_settings_module'

[intgr]

Looks like some interaction between djangorestframework-stubs and django-stubs.

[sobolevn]

Oh, good catch! I've change the signature of DjangoContext, so we would need to change it here as well: https://github.com/typeddjango/djangorestframework-stubs/blob/8709db5d2af980919a46072725ab54ca637a8703/mypy_drf_plugin/main.py#L25-L26

I've opened typeddjango/djangorestframework-stubs#432

[UnknownPlatypus]

If I understand well, this makes it possible to use django-stubs along django-configuration or django-split-settings but the types inferred will be Any right ?

To have more accurate typing, one should make his own plugin ?

[sobolevn]

If I understand well, this makes it possible to use django-stubs along django-configuration or django-split-settings but the types inferred will be Any right ?

Yes!

To have more accurate typing, one should make his own plugin ?

I can work on this later on, I need a way to infer mypy types from runtime types. I have a prototype that does just this. But, I need to polish it for a bit more.

[sobolevn]

I want to merge this today, so I can work on #1568

@intgr any other comments? :)

[intgr]

Sorry, I was away for a few days. But looks good to me now.

[sobolevn]

No worries, happy to see that you like my fix :)

[kaldown]

This do not work with django-configurations.

[tool.mypy]
mypy_path = "./src"
plugins = ["mypy_django_plugin.main"]

[tool.django-stubs]
django_settings_module = "myproj.settings"
strict_settings = false

returns an Error:

Error constructing plugin instance of NewSemanalDjangoPlugin
...
raise ImproperlyConfigured(install_failure)
django.core.exceptions.ImproperlyConfigured: django-configurations settings importer wasn't correctly installed. Please use one of the starter functions to install it as mentioned in the docs: https://django-configurations.readthedocs.io/

Whilst commenting usage of django-stubs in [tool.mypy] directive of pyproject.toml leading to expected issue of mypy not being able to catch django types from models.py (for example).

As I see this PR #180 is still open.
Would it be better to remove django-configurations entry from README.md since it could cause confusion?

[intgr]

@kaldown Please open a separate issue about this.

[kaldown]

@intgr thank you, for the fast reply. Do you think it's better to open another one in addition to #180?

[intgr]

Yes.

[kaldown]

Done: #1709