Fix PageNumberPagination.paginate_queryset() return type (#165)

* PageNumberPagination.paginate_queryset() should return a List of the underlying QuerySet's model, not Page.

* Add typecheck test for PageNumberPagination.paginate_queryset().

* Add typecheck test exclusion for new test in DRF.

Note that this has nothing to do with the change to the
paginate_queryset() type signature.

Author: richardxia

rest_framework-stubs/pagination.pyi

@@ -63,8 +63,8 @@ class PageNumberPagination(BasePagination):
     request: Optional[Request] = ...
     template: str = ...
     def paginate_queryset(
-        self, queryset: QuerySet, request: Request, view: Optional[APIView] = ...
-    ) -> Optional[List[Page]]: ...
+        self, queryset: QuerySet[_MT], request: Request, view: Optional[APIView] = ...
+    ) -> Optional[List[_MT]]: ...
     def get_paginated_response_schema(self, schema: Dict[str, Any]) -> Dict[str, Any]: ...
     def get_schema_fields(self, view: APIView) -> List[CoreAPIField]: ...
     def get_schema_operation_parameters(self, view: APIView) -> List[Dict[str, Any]]: ...

scripts/typecheck_tests.py

@@ -105,6 +105,7 @@
         '"MultipleChoiceField[Model]" has no attribute "partial"',
         'Argument 1 to "to_internal_value" of "Field" has incompatible type "Dict[str, str]"; expected "List[Any]"',
         'Module "rest_framework.fields" has no attribute "DjangoImageField"; maybe "ImageField"?',
+        'Argument 1 to "ListField" has incompatible type "CharField"; expected "bool"',
     ],
     "test_filters.py": [
         'Module has no attribute "coreapi"',

tests/typecheck/test_pagination.yml

@@ -0,0 +1,12 @@
+- case: test_page_number_pagination_paginate_queryset
+  main: |
+    from rest_framework.pagination import PageNumberPagination
+    from rest_framework.request import Request
+    from django.contrib.auth.models import User
+    from django.db.models import QuerySet
+
+    paginator = PageNumberPagination()
+    request: Request
+    queryset: QuerySet[User]
+    page = paginator.paginate_queryset(queryset, request)
+    reveal_type(page)  # N: Revealed type is "Union[builtins.list[django.contrib.auth.models.User*], None]"