feat: support returning pydantic model as result

ninja/operation.py

@@ -255,26 +255,31 @@ def _result_to_response(
             # Empty response.
             return temporal_response
 
-        resp_object = ResponseObject(result)
-        # ^ we need object because getter_dict seems work only with model_validate
-        validated_object = response_model.model_validate(
-            resp_object, context={"request": request, "response_status": status}
-        )
-
-        model_dump_kwargs: Dict[str, Any] = {}
+        model_dump_kwargs: Dict[str, Any] = {
+            "by_alias": self.by_alias,
+            "exclude_unset": self.exclude_unset,
+            "exclude_defaults": self.exclude_defaults,
+            "exclude_none": self.exclude_none,
+        }
         if pydantic_version >= [2, 7]:
             # pydantic added support for serialization context at 2.7
-            model_dump_kwargs.update(
-                context={"request": request, "response_status": status}
+            model_dump_kwargs.update(context={"request": request, "response_status": status})
+
+        response_schema = response_model.__annotations__["response"]
+        if (
+            isinstance(response_schema, type)
+            and issubclass(response_schema, pydantic.BaseModel)
+            and isinstance(result, response_schema)
+        ):
+            validated_object = result
+            result = validated_object.model_dump(**model_dump_kwargs)
+        else:
+            # ^ we need object because getter_dict seems work only with model_validate
+            validated_object = response_model.model_validate(
+                ResponseObject(result), context={"request": request, "response_status": status}
             )
+            result = validated_object.model_dump(**model_dump_kwargs)["response"]
 
-        result = validated_object.model_dump(
-            by_alias=self.by_alias,
-            exclude_unset=self.exclude_unset,
-            exclude_defaults=self.exclude_defaults,
-            exclude_none=self.exclude_none,
-            **model_dump_kwargs,
-        )["response"]
         return self.api.create_response(
             request, result, temporal_response=temporal_response
         )

tests/test_response.py

@@ -40,6 +40,10 @@ def to_camel(string: str) -> str:
     return "".join(word.capitalize() for word in string.split("_"))
 
 
+class MessageModel(BaseModel):
+    message: str
+
+
 class UserModel(BaseModel):
     id: int
     user_name: str
@@ -67,6 +71,14 @@ def check_model_alias(request):
     return User(1, "John", "Password")
 
 
+@router.get("/check_pydantic", response={200: UserModel, 201: MessageModel}, by_alias=True)
+def check_pydantic(request, message_only: bool):
+    print(message_only)
+    if message_only:
+        return 201, {"message": "Created"}
+    return 200, UserModel(id=1, user_name="John")
+
+
 @router.get("/check_union", response=Union[int, UserModel])
 def check_union(request, q: int):
     if q == 0:
@@ -99,23 +111,26 @@ def check_del_cookie(request, response: HttpResponse):
 
 
 @pytest.mark.parametrize(
-    "path,expected_response",
+    "path,expected_status_code,expected_response",
     [
-        ("/check_int", 1),
-        ("/check_model", {"id": 1, "user_name": "John"}),  # the password is skipped
+        ("/check_int", 200, 1),
+        ("/check_model", 200, {"id": 1, "user_name": "John"}),  # the password is skipped
         (
             "/check_list_model",
+            200,
             [{"id": 1, "user_name": "John"}],
         ),  # the password is skipped
-        ("/check_model", {"id": 1, "user_name": "John"}),  # the password is skipped
-        ("/check_model_alias", {"Id": 1, "UserName": "John"}),  # result is Camal Case
-        ("/check_union?q=0", 1),
-        ("/check_union?q=1", {"id": 1, "user_name": "John"}),
+        ("/check_model", 200, {"id": 1, "user_name": "John"}),  # the password is skipped
+        ("/check_model_alias", 200, {"Id": 1, "UserName": "John"}),  # result is Camal Case
+        ("/check_pydantic?message_only=0", 200, {"Id": 1, "UserName": "John"}),  # result is Camal Case
+        ("/check_pydantic?message_only=1", 201, {"message": "Created"}),
+        ("/check_union?q=0", 200, 1),
+        ("/check_union?q=1", 200, {"id": 1, "user_name": "John"}),
     ],
 )
-def test_responses(path, expected_response):
+def test_responses(path, expected_status_code, expected_response):
     response = client.get(path)
-    assert response.status_code == 200, response.content
+    assert response.status_code == expected_status_code, response.content
     assert response.json() == expected_response
     assert response.data == response.data == expected_response  # Ensures cache works