APIRequestFactory Request object has no attribute session

[edchelstephens]

Hi,

I encountered this exception:
Exception: 'Request' object has no attribute 'session'

Upun running an APITestCase on an APIView which logs in a user given the correct credentials and also returns the auth token key in a json response.

The simplified logic of the APIView looks this:

from rest_framework.authtoken.serializers import AuthTokenSerializer
from rest_framework.views import APIView
from rest_framework.response import Response
from rest_framework.authtoken.models import Token

from django.contrib.auth import login

class ObtainAuthToken(APIView):
    serializer_class = AuthTokenSerializer

    def post(self, request, *args, **kwargs):
        serializer = self.serializer_class(data=request.data)
        if serializer.is_valid():
            user = serializer.validated_data["user"]
            token, created = Token.objects.get_or_create(user=user)
            login(request, user)
            response = {
                "token": token.key
            }
            return Response(response, status=200)
        else:
            return Response("Invalid username/password", status=401)

And the APITestCase looks like this:

from rest_framework.test import APIRequestFactory, APITestCase

from api.views import ObtainAuthToken

class ObtainAuthTokenTestCase(APITestCase):
    """Test case for ObtainAuthToken api endpoint."""

    def setUp(self):
        self.url = "api/api-auth/"
        self.request_factory = APIRequestFactory()
        self.view = ObtainAuthToken.as_view()


    def test_correct_credentials_can_login(self):
        """Test user with overriden credentials can login and obtain token."""
        
        email_as_username="[email protected]"
        password="SamplePassword@123"

        user = User.objects.get(email=email_as_username)
        user.set_password(password)
        user.save()
        
        data = {
            "username": email_as_username,
            "password": password
        }

        request = self.request_factory.post(self.url, data)
        response = self.view(request)
        
        self.assertEqual(response.status_code, 200)

Test invocation with coverage:
coverage run manage.py test --keepdb --verbosity=2

Output:

test_correct_credentials_can_login (project.tests.test_views.ObtainAuthTokenTestCase)
Test user with overriden credentials can login and obtain token. ... FAIL

======================================================================
FAIL: test_correct_credentials_can_login (project.tests.test_views.ObtainAuthTokenTestCase)
Test user with overriden credentials can login and obtain token.
----------------------------------------------------------------------
Traceback (most recent call last):
File "/home/ed/projects/project/tests/test_views.py", line 38, in test_correct_credentials_can_login
    self.assertEqual(response.status_code, 200)
AssertionError: 500 != 200

----------------------------------------------------------------------
Ran 1 test in 0.039s

When I debug the exception traceback, with my custom function, I get this:

    ==================== Exception Occurred ====================
    Exception: 'Request' object has no attribute 'session'
    Type: <class 'AttributeError'>
    Function/Method/Caller: post
    Location: /api/views.py
    Line: 143
    ============================================================

===============================================================================

But when I comment out the login(request, user) line, as in:

#login(request, user)

test_correct_credentials_can_login (project.tests.test_views.ObtainAuthTokenTestCase)
Test user with overriden credentials can login and obtain token. ... ok

----------------------------------------------------------------------
Ran 1 test in 0.019s

OK

The test succeeds...

When checking the https://docs.djangoproject.com/en/2.2/_modules/django/contrib/auth/#login login() function it does access the .session attribute of the request

But according to the exception the Request object generated from APIRequestFactory does not have have it!

Why does APIRequestFactory request object does not have a session attribute??

How can I fix this? I don't want to remove the login() part, of course.

Any help, pointers is highly appreciated. Thank you!

===============================================================================

Package versions
djangorestframework==3.11.1
Django==2.2.16
Python 3.6.9
coverage==5.5

Platform
Ubuntu 20.04.2 LTS

[edchelstephens]

I fixed it by manually adding SessionMiddleware on the request, following this answer on a similar issue from stack overflow.

https://stackoverflow.com/questions/35659676/django-test-case-error-wsgirequest-object-has-no-attribute-session

I just created a mixin and made my test inherit it and then just call the add_session() method.

from django.contrib.sessions.middleware import SessionMiddleware

class SessionRequiredTestMixin:
    """Mixin for tests with request.session, cookies operations and requirements."""

    def add_session(self, request):
        """Add session object to request by using SessionMiddleware."""
        middleware = SessionMiddleware()
        middleware.process_request(request)
        request.session.save()
        
        
class ObtainAuthTokenTestCase(SessionRequiredTestMixin, APITestCase):
   
    def test_correct_credentials_can_login(self):
     ...
     request = self.request_factory.post(self.url, data)
     self.add_session(request)
     response = self.view(request)