Parametrize concrete factories, add tests

factory/base.py

@@ -656,7 +656,7 @@ def __init__(self, **kwargs):
             setattr(self, field, value)
 
 
-class StubFactory(Factory[T]):
+class StubFactory(Factory[StubObject]):
 
     class Meta:
         strategy = enums.STUB_STRATEGY
@@ -688,7 +688,7 @@ def _create(cls, model_class, *args, **kwargs):
         return cls._build(model_class, *args, **kwargs)
 
 
-class DictFactory(BaseDictFactory[T]):
+class DictFactory(BaseDictFactory[dict]):
     class Meta:
         model = dict
 
@@ -714,7 +714,7 @@ def _create(cls, model_class, *args, **kwargs):
         return cls._build(model_class, *args, **kwargs)
 
 
-class ListFactory(BaseListFactory[T]):
+class ListFactory(BaseListFactory[list]):
     class Meta:
         model = list
 

tests/test_typing.py

@@ -3,6 +3,8 @@
 import dataclasses
 import unittest
 
+from typing_extensions import assert_type
+
 import factory
 
 
@@ -25,7 +27,21 @@ class UserFactory(factory.Factory[User]):
             class Meta:
                 model = User
 
-        result: User
-        result = UserFactory.build()
-        result = UserFactory.create()
-        self.assertEqual(result.name, "John Doe")
+        assert_type(UserFactory.build(), User)
+        assert_type(UserFactory.create(), User)
+        assert_type(UserFactory.build_batch(2), list[User])
+        assert_type(UserFactory.create_batch(2), list[User])
+        self.assertEqual(UserFactory.create().name, "John Doe")
+
+    def test_dict_factory(self) -> None:
+
+        class Pet(factory.DictFactory):
+            species = "dog"
+            name = "rover"
+
+        assert_type(Pet.build(), dict)
+        assert_type(Pet.create(), dict)
+
+    def test_list_factory(self) -> None:
+        assert_type(factory.ListFactory().build(), list)
+        assert_type(factory.ListFactory().create(), list)

tox.ini

@@ -36,6 +36,7 @@ passenv =
     POSTGRES_DATABASE
 deps =
     mypy
+    typing_extensions
     alchemy: SQLAlchemy
     alchemy: sqlalchemy_utils
     mongo: mongoengine