convince mypy that user.is_staff (and friends) are booleans (#542)

closes #512

Co-authored-by: proxi <51172302+3n-k1@users.noreply.github.com>

mypy_django_plugin/lib/fullnames.py

@@ -1,3 +1,5 @@
+ABSTRACT_USER_MODEL_FULLNAME = "django.contrib.auth.models.AbstractUser"
+PERMISSION_MIXIN_CLASS_FULLNAME = "django.contrib.auth.models.PermissionsMixin"
 MODEL_CLASS_FULLNAME = "django.db.models.base.Model"
 FIELD_FULLNAME = "django.db.models.fields.Field"
 CHAR_FIELD_FULLNAME = "django.db.models.fields.CharField"

mypy_django_plugin/main.py

@@ -22,7 +22,7 @@ from mypy_django_plugin.django.context import DjangoContext
 from mypy_django_plugin.lib import fullnames, helpers
 from mypy_django_plugin.transformers import fields, forms, init_create, meta, querysets, request, settings
 from mypy_django_plugin.transformers.managers import create_new_manager_class_from_from_queryset_method
-from mypy_django_plugin.transformers.models import process_model_class
+from mypy_django_plugin.transformers.models import process_model_class, set_auth_user_model_boolean_fields
 
 
 def transform_model_class(ctx: ClassDefContext, django_context: DjangoContext) -> None:
@@ -270,8 +270,12 @@ class NewSemanalDjangoPlugin(Plugin):
             return partial(settings.get_type_of_settings_attribute, django_context=self.django_context)
 
         info = self._get_typeinfo_or_none(class_name)
+        if info and info.has_base(fullnames.PERMISSION_MIXIN_CLASS_FULLNAME) and attr_name == "is_superuser":
+            return partial(set_auth_user_model_boolean_fields, django_context=self.django_context)
         if info and info.has_base(fullnames.HTTPREQUEST_CLASS_FULLNAME) and attr_name == "user":
             return partial(request.set_auth_user_model_as_type_for_request_user, django_context=self.django_context)
+        if info and info.has_base(fullnames.ABSTRACT_USER_MODEL_FULLNAME) and attr_name in ("is_staff", "is_active"):
+            return partial(set_auth_user_model_boolean_fields, django_context=self.django_context)
         return None
 
     def get_dynamic_class_hook(self, fullname: str) -> Optional[Callable[[DynamicClassDefContext], None]]:

mypy_django_plugin/transformers/models.py

@@ -5,7 +5,7 @@ from django.db.models.fields import DateField, DateTimeField
 from django.db.models.fields.related import ForeignKey
 from django.db.models.fields.reverse_related import ManyToManyRel, ManyToOneRel, OneToOneRel
 from mypy.nodes import ARG_STAR2, Argument, Context, FuncDef, TypeInfo, Var
-from mypy.plugin import ClassDefContext
+from mypy.plugin import AttributeContext, ClassDefContext
 from mypy.plugins import common
 from mypy.semanal import SemanticAnalyzer
 from mypy.types import AnyType, Instance
@@ -355,3 +355,9 @@ def process_model_class(ctx: ClassDefContext, django_context: DjangoContext) ->
         except helpers.IncompleteDefnException:
             if not ctx.api.final_iteration:
                 ctx.api.defer()
+
+
+def set_auth_user_model_boolean_fields(ctx: AttributeContext, django_context: DjangoContext) -> MypyType:
+    boolinfo = helpers.lookup_class_typeinfo(helpers.get_typechecker_api(ctx), bool)
+    assert boolinfo is not None
+    return Instance(boolinfo, [])

tests/typecheck/contrib/auth/test_misc.yml

@@ -13,3 +13,25 @@
         from django.test import Client
 
         get_user(Client())
+-   case: test_user_fields
+    main: |
+        from typing import Union
+        from django.contrib.auth.models import AnonymousUser, User
+
+        anonymous: AnonymousUser
+        anonymous_is_staff: bool = anonymous.is_staff
+        anonymous_is_active: bool = anonymous.is_active
+        anonymous_is_superuser: bool = anonymous.is_superuser
+        anonymous_is_authenticated: bool = anonymous.is_authenticated
+
+        user: User
+        user_is_staff: bool = user.is_staff
+        user_is_active: bool = user.is_active
+        user_is_superuser: bool = user.is_superuser
+        user_is_authenticated: bool = user.is_authenticated
+
+        union: Union[User, AnonymousUser]
+        union_is_staff: bool = union.is_staff
+        union_is_active: bool = union.is_active
+        union_is_superuser: bool = union.is_superuser
+        union_is_authenticated: bool = union.is_authenticated

tests/typecheck/models/test_contrib_models.yml

@@ -6,8 +6,8 @@
         reveal_type(User().first_name)  # N: Revealed type is 'builtins.str*'
         reveal_type(User().last_name)  # N: Revealed type is 'builtins.str*'
         reveal_type(User().email)  # N: Revealed type is 'builtins.str*'
-        reveal_type(User().is_staff)  # N: Revealed type is 'builtins.bool*'
+        reveal_type(User().is_staff)  # N: Revealed type is 'builtins.bool'
-        reveal_type(User().is_active)  # N: Revealed type is 'builtins.bool*'
+        reveal_type(User().is_active)  # N: Revealed type is 'builtins.bool'
         reveal_type(User().date_joined)  # N: Revealed type is 'datetime.datetime*'
         reveal_type(User().last_login)  # N: Revealed type is 'Union[datetime.datetime, None]'
         reveal_type(User().is_authenticated)  # N: Revealed type is 'Literal[True]'
@@ -22,7 +22,7 @@
         reveal_type(Permission().codename)  # N: Revealed type is 'builtins.str*'
 
         from django.contrib.auth.models import PermissionsMixin
-        reveal_type(PermissionsMixin().is_superuser)  # N: Revealed type is 'builtins.bool*'
+        reveal_type(PermissionsMixin().is_superuser)  # N: Revealed type is 'builtins.bool'
 
         from django.contrib.auth.models import Group
         reveal_type(Group().name)  # N: Revealed type is 'builtins.str*'