Pytest returns JSONDecodeError

[Llibyddap]

Still working through exactly how everything fits together (great project that does everything) - but finally got around to testing the code after noticing that the Swagger UI would post data into the DB (verified in pgAdmin), but would throw a response error.

To start fresh - pulled a new version of everything and ran the test from a clean install - same error...

============================= test session starts ==============================
platform linux -- Python 3.7.4, pytest-5.1.2, py-1.8.0, pluggy-0.12.0
rootdir: /app/app/tests
collected 23 items

app/app/tests/api/api_v1/test_celery.py .                                [  4%]
app/app/tests/api/api_v1/test_items.py FF                                [ 13%]
app/app/tests/api/api_v1/test_login.py .F                                [ 21%]
app/app/tests/api/api_v1/test_users.py FFF..F                            [ 47%]
app/app/tests/crud/test_item.py ....                                     [ 65%]
app/app/tests/crud/test_user.py ........                                 [100%]

=================================== FAILURES ===================================
_______________________________ test_create_item _______________________________

superuser_token_headers = {'Authorization': 'Bearer eyJ0eXAiOiJ...o7a_gBBlGdepjpY'}

    def test_create_item(superuser_token_headers):
        server_api = get_server_api()
        data = {"title": "Foo", "description": "Fighters"}
        response = requests.post(
            f"{server_api}{config.API_V1_STR}/items/",
            headers=superuser_token_headers,
            json=data,
        )
>       content = response.json()

app/app/tests/api/api_v1/test_items.py:16: 
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 
usr/local/lib/python3.7/site-packages/requests/models.py:897: in json
    return complexjson.loads(self.text, **kwargs)
usr/local/lib/python3.7/json/__init__.py:348: in loads
    return _default_decoder.decode(s)
usr/local/lib/python3.7/json/decoder.py:337: in decode
    obj, end = self.raw_decode(s, idx=_w(s, 0).end())
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 

self = <json.decoder.JSONDecoder object at 0x7f3f7d41d510>
s = 'Internal Server Error', idx = 0

    def raw_decode(self, s, idx=0):
        """Decode a JSON document from ``s`` (a ``str`` beginning with
        a JSON document) and return a 2-tuple of the Python
        representation and the index in ``s`` where the document ended.
    
        This can be used to decode a JSON document from a string that may
        have extraneous data at the end.
    
        """
        try:
            obj, end = self.scan_once(s, idx)
        except StopIteration as err:
>           raise JSONDecodeError("Expecting value", s, err.value) from None
E           json.decoder.JSONDecodeError: Expecting value: line 1 column 1 (char 0)

usr/local/lib/python3.7/json/decoder.py:355: JSONDecodeError

You can see that the tests all fail on same JSON decoding. I've tried each of the failed tests and noted the same behavior - the POSTs will update the db - but returning information from the bd has the decoder error...

Here is an example of a successful POST to the database of an item but the response fails.

backend_1        | INFO: ('172.21.0.5', 57326) - "POST /api/v1/items/ HTTP/1.1" 500
backend_1        | ERROR: Exception in ASGI application
backend_1        | Traceback (most recent call last):
backend_1        |   File "/usr/local/lib/python3.7/site-packages/uvicorn/protocols/http/httptools_impl.py", line 368, in run_asgi
backend_1        |     result = await app(self.scope, self.receive, self.send)
backend_1        |   File "/usr/local/lib/python3.7/site-packages/starlette/applications.py", line 133, in __call__
backend_1        |     await self.error_middleware(scope, receive, send)
backend_1        |   File "/usr/local/lib/python3.7/site-packages/starlette/middleware/errors.py", line 177, in __call__
backend_1        |     raise exc from None
backend_1        |   File "/usr/local/lib/python3.7/site-packages/starlette/middleware/errors.py", line 155, in __call__
backend_1        |     await self.app(scope, receive, _send)
backend_1        |   File "/usr/local/lib/python3.7/site-packages/starlette/middleware/base.py", line 25, in __call__
backend_1        |     response = await self.dispatch_func(request, self.call_next)
backend_1        |   File "./app/main.py", line 34, in db_session_middleware
backend_1        |     response = await call_next(request)
backend_1        |   File "/usr/local/lib/python3.7/site-packages/starlette/middleware/base.py", line 45, in call_next
backend_1        |     task.result()
backend_1        |   File "/usr/local/lib/python3.7/site-packages/starlette/middleware/base.py", line 38, in coro
backend_1        |     await self.app(scope, receive, send)
backend_1        |   File "/usr/local/lib/python3.7/site-packages/starlette/middleware/cors.py", line 84, in __call__
backend_1        |     await self.simple_response(scope, receive, send, request_headers=headers)
backend_1        |   File "/usr/local/lib/python3.7/site-packages/starlette/middleware/cors.py", line 140, in simple_response
backend_1        |     await self.app(scope, receive, send)
backend_1        |   File "/usr/local/lib/python3.7/site-packages/starlette/exceptions.py", line 73, in __call__
backend_1        |     raise exc from None
backend_1        |   File "/usr/local/lib/python3.7/site-packages/starlette/exceptions.py", line 62, in __call__
backend_1        |     await self.app(scope, receive, sender)
backend_1        |   File "/usr/local/lib/python3.7/site-packages/starlette/routing.py", line 590, in __call__
backend_1        |     await route(scope, receive, send)
backend_1        |   File "/usr/local/lib/python3.7/site-packages/starlette/routing.py", line 208, in __call__
backend_1        |     await self.app(scope, receive, send)
backend_1        |   File "/usr/local/lib/python3.7/site-packages/starlette/routing.py", line 41, in app
backend_1        |     response = await func(request)
backend_1        |   File "/usr/local/lib/python3.7/site-packages/fastapi/routing.py", line 124, in app
backend_1        |     skip_defaults=response_model_skip_defaults,
backend_1        |   File "/usr/local/lib/python3.7/site-packages/fastapi/routing.py", line 56, in serialize_response
backend_1        |     raise ValidationError(errors, field.type_)
backend_1        | pydantic.error_wrappers.ValidationError: 1 validation error for Item
backend_1        | response
backend_1        |   value is not a valid dict (type=type_error.dict)

There are no changes to the code... As I'm slightly better than noob status, it's possible that I've missed something in the install workflow - but, if so, can't find it. Any help or a point in the right direction would be greatly appreciated.

[ebreton]

I would say you are hitting the same wall as others with the (not yet implemented) orm_mode.

You can check https://github.com/tiangolo/full-stack-fastapi-postgresql/pull/43/files and let us know if that does not resolve your issue 🤞

[Llibyddap]

Yes - this was exactly the issue and it resolves to a Successful Response now... Thanks. My homework now is to understand why.

Thanks.

[ebreton]

Well @Llibyddap , the explanation is a long story that involves a PR from tiangolo in pydantic itself... but the point is that this repo has not been properly updated (yet) to support the new version of fastapi

that's for @tiangolo to fix 😁

Happy digging 👨‍🏭

[tiangolo]

Thanks for the help here @ebreton ! 👏 🙇

Thanks for reporting back and closing the issue @Llibyddap 👍