How to test an API endpoint with Django-rest-framework using Django-oauth-toolkit for authentication

Question

I have a Django-rest-framework viewset/router to define an API endpoint. The viewset is defined as such:

class DocumentViewSet(viewsets.ModelViewSet):
    permission_classes = [permissions.IsAuthenticated, TokenHasReadWriteScope]
    model = Document

And the router is defined as

router = DefaultRouter()
router.register(r'documents', viewsets.DocumentViewSet)

with url pattern url(r'^api/', include(router.urls))

I can hit this endpoint in the browser/through curl just fine by getting the right access token and using it for authorization. However, it's not clear how to write tests against this endpoint.

Here is what I've tried:

class DocumentAPITests(APITestCase):
    def test_get_all_documents(self):
        user = User.objects.create_user('test', '[email protected]', 'test')
        client = APIClient()
        client.credentials(username="test", password="test")
        response = client.get("/api/documents/")
        self.assertEqual(response.status_code, 200) 

This fails with an HTTP 401 response from the client.get() call. What is the right way to test an API endpoint in DRF using django-oauth-toolkit for oauth2 authentication?

Answer 1

When you are writing tests, you should aim to extract anything you are not testing from the test itself, typically putting any setup code in the setUp method of the test. In the case of API tests with OAuth, this usually includes the test user, OAuth application, and the active access token.

For django-oauth-toolkit, and other Django applications, I would always recommend looking at the tests to see how they do it. This allows you to avoid making unneeded API calls, especially for multi-part processes like OAuth, and only create the few model objects that are required.

def setUp(self):
    self.test_user = UserModel.objects.create_user("test_user", "[email protected]", "123456")

    self.application = Application(
        name="Test Application",
        redirect_uris="http://localhost",
        user=self.test_user,
        client_type=Application.CLIENT_CONFIDENTIAL,
        authorization_grant_type=Application.GRANT_AUTHORIZATION_CODE,
    )
    self.application.save()

def test_revoke_access_token(self):
    from datetime import datetime
    from django.utils import timezone

    tok = AccessToken.objects.create(
        user=self.test_user, token='1234567890',
        application=self.application, scope='read write',
        expires=timezone.now() + datetime.timedelta(days=1)
    )

From there you just need to authenticate using the token that has been generated. You can do this by injecting the Authorization header, or you can use the force_authenticate method provided by Django REST Framework.