fixup! Add a generic type parameter 'through' to ManyRelatedManager

django-stubs/db/models/fields/related_descriptors.pyi

@@ -15,7 +15,7 @@ from typing_extensions import Self
 _M = TypeVar("_M", bound=Model)
 _F = TypeVar("_F", bound=Field)
 _From = TypeVar("_From", bound=Model)
-_Through = TypeVar("_Through", bound=Model)
+_Through = TypeVar("_Through", bound=Model, default=Model)
 _To = TypeVar("_To", bound=Model)
 
 class ForeignKeyDeferredAttribute(DeferredAttribute):

ext/django_stubs_ext/db/models/manager.py

@@ -13,12 +13,12 @@
     from typing import Protocol, TypeVar
 
     _T = TypeVar("_T")
-    _M = TypeVar("_M")
+    _Through = TypeVar("_Through")
 
     # Define as `Protocol` to prevent them being used with `isinstance()`.
     # These actually inherit from `BaseManager`.
     class RelatedManager(Protocol[_T]):
         pass
 
-    class ManyRelatedManager(Protocol[_T, _M]):
+    class ManyRelatedManager(Protocol[_T, _Through]):
         pass

mypy_django_plugin/transformers/manytomany.py

@@ -151,6 +151,17 @@ def get_model_from_expression(
 
 
 def get_related_manager_and_model(ctx: MethodContext) -> Optional[Tuple[Instance, Instance, Instance]]:
+    """
+    Returns a 3-tuple consisting of:
+      1. A `ManyRelatedManager` instance
+      2. The first type parameter instance of 1. when it's a model
+      3. The second type parameter instance of 1. when it's a model
+    When encountering a `ManyRelatedManager` that has populated its 2 first type
+    parameters with models. Otherwise `None` is returned.
+
+    For example: if given a `ManyRelatedManager[A, B]` where `A` and `B` are models the
+    following 3-tuple is returned: `(ManyRelatedManager[A, B], A, B)`.
+    """
     if (
         isinstance(ctx.default_return_type, Instance)
         and ctx.default_return_type.type.fullname == fullnames.MANY_RELATED_MANAGER

tests/typecheck/fields/test_related.yml

@@ -603,7 +603,7 @@
         from myapp.models import Author, Blog, Publisher, Profile
         reveal_type(Author.blogs)  # N: Revealed type is "django.db.models.fields.related_descriptors.ManyToManyDescriptor[myapp.models.Blog, myapp.models.Author_blogs]"
         reveal_type(Author.blogs.through)  # N: Revealed type is "Type[myapp.models.Author_blogs]"
-        reveal_type(Author().blogs)  # N: Revealed type is "myapp.models.Blog_ManyRelatedManager"
+        reveal_type(Author().blogs)  # N: Revealed type is "myapp.models.Blog_ManyRelatedManager[myapp.models.Author_blogs]"
         reveal_type(Blog.publisher)  # N: Revealed type is "django.db.models.fields.related_descriptors.ForwardManyToOneDescriptor[django.db.models.fields.related.ForeignKey[Union[myapp.models.Publisher, django.db.models.expressions.Combinable], myapp.models.Publisher]]"
         reveal_type(Publisher.profile)  # N: Revealed type is "django.db.models.fields.related_descriptors.ForwardOneToOneDescriptor[django.db.models.fields.related.OneToOneField[Union[myapp.models.Profile, django.db.models.expressions.Combinable], myapp.models.Profile]]"
         reveal_type(Author.file)  # N: Revealed type is "django.db.models.fields.files.FileDescriptor"
@@ -946,8 +946,8 @@
     main: |
         from myapp.models import SalesMan
         sales_man = SalesMan()
-        reveal_type(sales_man.client) # N: Revealed type is "myapp.models.CustomUser_ManyRelatedManager"
-        reveal_type(sales_man.client(manager="staffs")) # N: Revealed type is "django.db.models.fields.related_descriptors.ManyRelatedManager[myapp.models.CustomUser]"
+        reveal_type(sales_man.client) # N: Revealed type is "myapp.models.CustomUser_ManyRelatedManager[myapp.models.SalesMan_client]"
+        reveal_type(sales_man.client(manager="staffs")) # N: Revealed type is "django.db.models.fields.related_descriptors.ManyRelatedManager[myapp.models.CustomUser, myapp.models.SalesMan_client]"
     installed_apps:
         - myapp
     files:
@@ -1279,7 +1279,7 @@
             instance = arg(field=1, unknown=2)
             reveal_type(instance.field)  # N: Revealed type is "Any"
             reveal_type(instance.unknown)  # N: Revealed type is "Any"
-            reveal_type(instance.bad)  # N: Revealed type is "django.db.models.fields.related_descriptors.ManyRelatedManager[Any]"
+            reveal_type(instance.bad)  # N: Revealed type is "django.db.models.fields.related_descriptors.ManyRelatedManager[Any, Any]"
             return instance
     installed_apps:
         -   myapp

tests/typecheck/models/test_contrib_models.yml

@@ -163,10 +163,10 @@
 -   case: test_permissions_inherited_reverese_relations
     main: |
         from django.contrib.auth.models import Permission
-        reveal_type(Permission().user_set)  # N: Revealed type is "django.contrib.auth.models.User_ManyRelatedManager"
+        reveal_type(Permission().user_set)  # N: Revealed type is "django.contrib.auth.models.User_ManyRelatedManager[django.contrib.auth.models.User_user_permissions]"
 
         from django.contrib.auth.models import Group
-        reveal_type(Group().user_set)  # N: Revealed type is "django.contrib.auth.models.User_ManyRelatedManager"
+        reveal_type(Group().user_set)  # N: Revealed type is "django.contrib.auth.models.User_ManyRelatedManager[django.contrib.auth.models.User_groups]"
     custom_settings: |
         INSTALLED_APPS = ('django.contrib.contenttypes', 'django.contrib.auth')
         AUTH_USER_MODEL='auth.User'