Mocking fails when using Authlib HTTPX integration OAuth2 client

I’m trying to mock the responses from Keycloak using the Authlib HTTPX integration client for OAuth2.

I’m getting the following exception because the auth_flow() hook for the OAuth2 client is rewriting the request.url attribute so it is no longer a URLResponse object, it’s a plain URL (again).

_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 
/home/bobh/.virtualenvs/traffica_stc/lib/python3.7/site-packages/authlib/integrations/httpx_client/oauth2_client.py:109: in _fetch_token
    auth=auth, **kwargs)
/home/bobh/.virtualenvs/traffica_stc/lib/python3.7/site-packages/httpx/client.py:1316: in post
    timeout=timeout,
/home/bobh/.virtualenvs/traffica_stc/lib/python3.7/site-packages/authlib/integrations/httpx_client/oauth2_client.py:89: in request
    method, url, auth=auth, **kwargs)
/home/bobh/.virtualenvs/traffica_stc/lib/python3.7/site-packages/httpx/client.py:1097: in request
    request, auth=auth, allow_redirects=allow_redirects, timeout=timeout,
/home/bobh/.virtualenvs/traffica_stc/lib/python3.7/site-packages/respx/mocks.py:162: in unbound_async_send
    return await self.__AsyncClient__send__spy(client, request, **kwargs)
/home/bobh/.virtualenvs/traffica_stc/lib/python3.7/site-packages/respx/mocks.py:533: in __AsyncClient__send__spy
    response = await _AsyncClient__send(client, request, **kwargs)
/home/bobh/.virtualenvs/traffica_stc/lib/python3.7/site-packages/httpx/client.py:1118: in send
    request, auth=auth, timeout=timeout, allow_redirects=allow_redirects,
/home/bobh/.virtualenvs/traffica_stc/lib/python3.7/site-packages/httpx/client.py:1148: in send_handling_redirects
    request, auth=auth, timeout=timeout, history=history
/home/bobh/.virtualenvs/traffica_stc/lib/python3.7/site-packages/httpx/client.py:1184: in send_handling_auth
    response = await self.send_single_request(request, timeout)
/home/bobh/.virtualenvs/traffica_stc/lib/python3.7/site-packages/httpx/client.py:1208: in send_single_request
    response = await dispatcher.send(request, timeout=timeout)
/home/bobh/.virtualenvs/traffica_stc/lib/python3.7/site-packages/httpx/dispatch/connection_pool.py:157: in send
    raise exc
/home/bobh/.virtualenvs/traffica_stc/lib/python3.7/site-packages/httpx/dispatch/connection_pool.py:153: in send
    response = await connection.send(request, timeout=timeout)
/home/bobh/.virtualenvs/traffica_stc/lib/python3.7/site-packages/httpx/dispatch/connection.py:42: in send
    self.connection = await self.connect(timeout=timeout)
/home/bobh/.virtualenvs/traffica_stc/lib/python3.7/site-packages/httpx/dispatch/connection.py:63: in connect
    host, port, ssl_context, timeout
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 

self = <respx.mocks.HTTPXMock object at 0x7f1e34a9a898>
hostname = 'myhost', port = 443
ssl_context = <ssl.SSLContext object at 0x7f1e33f9b8b8>
timeout = Timeout(timeout=5.0)

    async def __Backend__open_tcp_stream__mock(
        self,
        hostname: str,
        port: int,
        ssl_context: typing.Optional[ssl.SSLContext],
        timeout: Timeout,
    ) -> BaseSocketStream:
        response = getattr(hostname, "attachment", None)  # Pickup attached template
>       return await response.socket_stream
E       AttributeError: 'NoneType' object has no attribute 'socket_stream'

By this time the response is gone so I don’t know what the mocked method could return. It would have to go back and re-match on the request (somehow).

Any ideas to work around or fix this? I’m happy to push a PR if someone can point me at a possible fix.

Thanks

[StephenBrown2]

For future @lundberg this is something that may/will change if/when Middleware becomes a thing: https://github.com/encode/httpx/pull/800

[firesock]

Sorry, only got around to updating our pin recently. I can confirm with authlib 0.15.1, httpx 0.16.1 and respx 0.14.0 the workaround is unnecessary.