Django Testing Endpoints

Writing a basic test

Generating the URL with reverse()

reverse() uses the name in urls.py

urls.py

from django.urls import path
from . import views

urlpatterns = (
    path("dashboard_query/<int:query_id>", views.run_dashboard_query, name="run_dashboard_query"),

Adding query params to reverse()

kwargs:

for a URL like /dashboard/<int:dashboard_id>, you could pass *args or **kwargs to set the dashboard_id

test_endpoint.py

from django.urls import reverse
from django.test import TestCase
from django.utils.http import urlencode


class TestEndpoint(TestCase):
    def _make_api_call(self, kwargs=None, query_kwargs=None):
    """ args/kwargs: keys in the path """
        "GET /app/dashboard_query/<query_id>"
        url = reverse("run_dashboard_query", kwargs=kwargs)
        if query_kwargs:
            url = f"{url}?{urlencode(kwargs)}"
        return self.client.get(url)

Auth

@classmethod
    def setUpTestData(cls):
        cls.user = UserFactory(is_superuser=True)

self.client.force_login(self.user)

HTTP Headers

Client.get docs

set HTTP headers with kwargs prefixed with HTTP_

# HTTP header will have `secret=...`
response = self.client.get(reverse("endpoint"), HTTP_SECRET=settings.SECRET)

Test endpoint with vanilla Django

test_endpoint.py

from django.test import TestCase
from django.urls import reverse
from django.utils.http import urlencode
from rest_framework import status

class TestEndpoint(TestCase):
    def test_endpoint(self):
        # Arrange
        user = UserFactory(is_superuser=False)

        # Act
        self.client.force_login(user)
        response = self._make_api_call({'query_id': 1})

        # Assert
        self.assertEqual(response.status_code, status.HTTP_200_OK)
        data = response.json()

Django Rest Framework helpers

status

• easier to read
• so that you don't have to memorize HTTP status codes

from rest_framework import status

self.assertEqual(response.status_code, status.HTTP_201_CREATED)

APITestCase and APIClient

vs vanilla Django

1. Nicer API to edit the header
   1. example: adding a SECRET to the HTTP header
2. the API is slightly nicer for JSON data

Vanilla Django

self.client.post(
            reverse("create_or_get_dashboard"),
            json.dumps(new_dashboard_data),
            content_type="application/json",
        )

DRF

self.client.post(
            reverse("create_or_get_dashboard"),
            new_dashboard_data,
            type="json",
        )

APITestCase overrides self.client with APIClient

force_authenticate vs force_login

TODO: ask a StackOverflow question

test_endpoint.py

- from django.test import TestCase
+ from rest_framework.test import APITestCase

- class TestEndpoint(TestCase):
+ class TestEndpoint(APITestCase):
    def test_endpoint(self):
        # Arrange
        user = UserFactory(is_superuser=False)

        # Act
-       self.client.force_login(user)
+       self.client.force_authenticate(user)
        response = self._make_api_call(kwargs={'query_id': 1}, query_kwargs={"year": 2022})

        # Assert
        self.assertEqual(response.status_code, 200)
        data = response.json() # or response.data

Request Factories

able to have a logged in user

• unlike Django’s RequestFactory

Pros

• You directly import & run your views
• so in your code editor, you can click into the view
  • instead of copying the url string name
  • and searching for it in urls.py

Cons

• a bit more boilerplate

• you should still generate the correct the URL with reverse()

  • (because the request that you pass to the view still needs to have a valid URL)

test_with_api_request_factory.py

from rest_framework.test import APITestCase, APIRequestFactory, force_authenticate
from .views import run_query_view

class TestEndpoint(APITestCase):
    def setupTests(self):
        self.factory = APIRequestFactory()
    def create_request(endpoint: str, user: User, query_params: Dict = None):
        request = factory.get("/app_name/some_path")
        # vanilla Django can only do request.user = user
        force_authenticate(request, user)
        response = run_query_view(request)

????

self.factory.get()

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Last update: 2023-04-24