From b76f9f4d9d4f8b4ce8f0f9f0938c81faaafc25c6 Mon Sep 17 00:00:00 2001
From: Petter Friberg <petter_friberg@hotmail.com>
Date: Thu, 1 Aug 2024 00:00:00 +0200
Subject: [PATCH] Improve `get_context_object_name` on `SingleObjectMixin` and
 `MultipleObjectMixin` (#2298)

---
 django-stubs/views/generic/detail.pyi         |  7 +++--
 django-stubs/views/generic/list.pyi           | 14 +++++++--
 tests/assert_type/views/generic.py            | 30 +++++++++++++++++++
 tests/typecheck/views/generic/test_detail.yml |  4 +--
 4 files changed, 48 insertions(+), 7 deletions(-)
 create mode 100644 tests/assert_type/views/generic.py

diff --git a/django-stubs/views/generic/detail.pyi b/django-stubs/views/generic/detail.pyi
index a833c72cc..b2f04dc47 100644
--- a/django-stubs/views/generic/detail.pyi
+++ b/django-stubs/views/generic/detail.pyi
@@ -1,4 +1,4 @@
-from typing import Any, Generic, TypeVar
+from typing import Any, Generic, TypeVar, overload
 
 from django.db import models
 from django.http import HttpRequest, HttpResponse
@@ -17,7 +17,10 @@ class SingleObjectMixin(Generic[_M], ContextMixin):
     def get_object(self, queryset: models.query.QuerySet[_M] | None = ...) -> _M: ...
     def get_queryset(self) -> models.query.QuerySet[_M]: ...
     def get_slug_field(self) -> str: ...
-    def get_context_object_name(self, obj: _M) -> str | None: ...
+    @overload
+    def get_context_object_name(self, obj: _M) -> str: ...
+    @overload
+    def get_context_object_name(self, obj: Any) -> str | None: ...
 
 class BaseDetailView(SingleObjectMixin[_M], View):
     object: _M
diff --git a/django-stubs/views/generic/list.pyi b/django-stubs/views/generic/list.pyi
index 01f68b27c..785a81aa8 100644
--- a/django-stubs/views/generic/list.pyi
+++ b/django-stubs/views/generic/list.pyi
@@ -1,12 +1,17 @@
 from collections.abc import Sequence
-from typing import Any, Generic, TypeVar
+from typing import Any, Generic, Protocol, TypeVar, overload, type_check_only
 
 from django.core.paginator import Page, Paginator, _SupportsPagination
 from django.db.models import Model, QuerySet
 from django.http import HttpRequest, HttpResponse
 from django.views.generic.base import ContextMixin, TemplateResponseMixin, View
 
-_M = TypeVar("_M", bound=Model, covariant=True)
+_M = TypeVar("_M", bound=Model)
+
+@type_check_only
+class _HasModel(Protocol):
+    @property
+    def model(self) -> type[Model]: ...
 
 class MultipleObjectMixin(Generic[_M], ContextMixin):
     allow_empty: bool
@@ -34,7 +39,10 @@ class MultipleObjectMixin(Generic[_M], ContextMixin):
     ) -> Paginator: ...
     def get_paginate_orphans(self) -> int: ...
     def get_allow_empty(self) -> bool: ...
-    def get_context_object_name(self, object_list: _SupportsPagination[_M]) -> str | None: ...
+    @overload
+    def get_context_object_name(self, object_list: _HasModel) -> str: ...
+    @overload
+    def get_context_object_name(self, object_list: Any) -> str | None: ...
     def get_context_data(
         self, *, object_list: _SupportsPagination[_M] | None = ..., **kwargs: Any
     ) -> dict[str, Any]: ...
diff --git a/tests/assert_type/views/generic.py b/tests/assert_type/views/generic.py
new file mode 100644
index 000000000..6147f02d7
--- /dev/null
+++ b/tests/assert_type/views/generic.py
@@ -0,0 +1,30 @@
+from typing import Optional, Type
+
+from django.db import models
+from django.views.generic.detail import SingleObjectMixin
+from django.views.generic.list import ListView
+from typing_extensions import assert_type
+
+
+class MyModel(models.Model): ...
+
+
+class MyDetailView(SingleObjectMixin[MyModel]): ...
+
+
+detail_view = MyDetailView()
+assert_type(detail_view.model, Type[MyModel])
+assert_type(detail_view.queryset, Optional[models.QuerySet[MyModel, MyModel]])
+assert_type(detail_view.get_context_object_name(MyModel()), str)
+assert_type(detail_view.get_context_object_name(1), Optional[str])
+
+
+class MyListView(ListView[MyModel]): ...
+
+
+list_view = MyListView()
+assert_type(list_view.model, Optional[Type[MyModel]])
+assert_type(list_view.queryset, Optional[models.QuerySet[MyModel, MyModel]])
+assert_type(list_view.get_context_object_name(models.QuerySet[MyModel]()), str)
+assert_type(list_view.get_context_object_name(MyModel()), Optional[str])
+assert_type(list_view.get_context_object_name(1), Optional[str])
diff --git a/tests/typecheck/views/generic/test_detail.yml b/tests/typecheck/views/generic/test_detail.yml
index 8e1713db4..6fa29f5c3 100644
--- a/tests/typecheck/views/generic/test_detail.yml
+++ b/tests/typecheck/views/generic/test_detail.yml
@@ -37,8 +37,8 @@
             def get_queryset(self) -> QuerySet[MyModel]:
                 self.get_object(super().get_queryset())
                 return super().get_queryset()
-    custom_settings: |
-        INSTALLED_APPS = ('myapp',)
+    installed_apps:
+        - myapp
     files:
         -   path: myapp/__init__.py
         -   path: myapp/models.py