class ViewSetTest(TestCase):
    def test_view_set(self):
        factory = APIRequestFactory()
        view = CatViewSet.as_view()
        cat = Cat(name="bob")
        cat.save()

        request = factory.get(reverse('cat-detail', args=(cat.pk,)))
        response = view(request)

AttributeError: 'NoneType' object has no attributes 'items'

def test_client_view(self):
    response = APIClient().get(reverse('cat-detail', args=(cat.pk,)))
    self.assertEqual(response.status_code, 200)

def test_view_set(self):
    request = APIRequestFactory().get("")
    cat_detail = CatViewSet.as_view({'get': 'retrieve'})
    cat = Cat.objects.create(name="bob")
    response = cat_detail(request, pk=cat.pk)
    self.assertEqual(response.status_code, 200)

{
    'get': 'retrieve',
    'put': 'update',
    'patch': 'partial_update',
    'delete': 'destroy'
}

class ViewSetTest(TestCase):
    def test_view_set(self):
        factory = APIRequestFactory()
        view = CatViewSet.as_view(actions={'get': 'retrieve'}) # <-- Changed line
        cat = Cat(name="bob")
        cat.save()

        request = factory.get(reverse('cat-detail', args=(cat.pk,)))
        response = view(request)

from django.core.urlresolvers import reverse, resolve
...
url = reverse('cat-list')
req = factory.get(url)
view = resolve(url).func
response = view(req)
response.render()

response = view(request)

from django.test import TestCase
from rest_framework.test import APIRequestFactory
from django.db.models.query import QuerySet
from rest_framework.test import force_authenticate
from django.contrib.auth.models import User

from config_app.models import Config
from config_app.apps import ConfigAppConfig
from config_app.views import ConfigViewSet

class ViewsTestCase(TestCase):
    def setUp(self):
        # Create a test instance
        self.config = Config.objects.create(
            ads='{"frequency": 1, "site_id": 1, "network_id": 1}',
            keys={}, methods={}, sections=[], web_app='{"image": 1, "label": 1, "url": 1}',
            subscriptions=[], name='test name', build='test build', version='1.0test', device='desktop',
            platform='android', client_id=None)

        # Create auth user for views using api request factory
        self.username = 'config_tester'
        self.password = 'goldenstandard'
        self.user = User.objects.create_superuser(self.username, 'test@example.com', self.password)

    def tearDown(self):
        pass

    @classmethod
    def setup_class(cls):
        """setup_class() before any methods in this class"""
        pass

    @classmethod
    def teardown_class(cls):
        """teardown_class() after any methods in this class"""
        pass

    def shortDescription(self):
        return None


    def test_view_set1(self):
        """
        No auth example
        """
        api_request = APIRequestFactory().get("")
        detail_view = ConfigViewSet.as_view({'get': 'retrieve'})
        response = detail_view(api_request, pk=self.config.pk)
        self.assertEqual(response.status_code, 401)

    def test_view_set2(self):
        """
        Auth using force_authenticate
        """
        factory = APIRequestFactory()
        user = User.objects.get(username=self.username)
        detail_view = ConfigViewSet.as_view({'get': 'retrieve'})

        # Make an authenticated request to the view...
        api_request = factory.get('')
        force_authenticate(api_request, user=user)
        response = detail_view(api_request, pk=self.config.pk)
        self.assertEqual(response.status_code, 200)