Use Mypy's strict mode

.pre-commit-config.yaml

@@ -68,3 +68,5 @@ repos:
   rev: v1.11.2
   hooks:
   - id: mypy
+    additional_dependencies:
+    - django-stubs==5.1.0

pyproject.toml

@@ -82,15 +82,10 @@ enable_error_code = [
   "redundant-expr",
   "truthy-bool",
 ]
-check_untyped_defs = true
-disallow_any_generics = true
-disallow_incomplete_defs = true
-disallow_untyped_defs = true
 mypy_path = "src/"
 namespace_packages = false
-no_implicit_optional = true
+strict = true
 warn_unreachable = true
-warn_unused_ignores = true
 
 [[tool.mypy.overrides]]
 module = "tests.*"

src/auto_prefetch/__init__.py

@@ -100,6 +100,7 @@ def _fetch_all(self) -> None:
         if (
             set_peers
             and issubclass(self._iterable_class, models.query.ModelIterable)
+            and self._result_cache is not None
             and len(self._result_cache) >= 2
         ):
             peers = WeakValueDictionary((id(o), o) for o in self._result_cache)
@@ -111,6 +112,8 @@ def _fetch_all(self) -> None:
 
 
 class Model(models.Model):
+    _peers: WeakValueDictionary[str, Model]
+
     class Meta:
         abstract = True
         base_manager_name = "prefetch_manager"
@@ -129,8 +132,8 @@ def __getstate__(self) -> dict[str, Any]:
         return res
 
     @classmethod
-    def check(cls, **kwargs: Any) -> list[checks.Error]:
-        errors: list[checks.Error] = super().check(**kwargs)
+    def check(cls, **kwargs: Any) -> list[checks.CheckMessage]:
+        errors: list[checks.CheckMessage] = super().check(**kwargs)
         errors.extend(cls._check_meta_inheritance())
         return errors
 

tests/test_basic.py

@@ -205,7 +205,7 @@ def test_multiples(django_assert_num_queries, Model, queries):
 
 @pytest.mark.django_db
 def test_garbage_collection():
-    def check_instances(num):
+    def check_instances(num: int) -> None:
         gc.collect()
         objs = [o for o in gc.get_objects() if isinstance(o, Prefetch)]
         assert len(objs) == num