Django is always returning 404 while testing. "The requested resource was not found on this server."

Question

I have an Django API that I build quickly, and now I want to add some tests to ensure is stable. The problem is that Django simply refuses to let me access any resource on the server. It can't find any URL.

I have some models, but this test is with the User model.

# auth/urls.py
urlpatterns = [
...
    path(
        "user/<str:email>/",
        views.UserView.as_view(),
        name="public staff user",
    ),
...
]

# auth/views/UserView.py (Folder working as a submodule)
... # Needed imports

from django.contrib.auth import get_user_model

UserModel = get_user_model()

class UserView(
    generics.RetrieveAPIView,
    generics.UpdateAPIView,
    generics.DestroyAPIView,
):
    serializer_class = UserSerializer
    lookup_field = "email"

    def get_queryset(self):
        return UserModel.objects.all()

# auth/tests/tests.py (Folder workign as a submodule, tests.py is a temporary name)
from django.test import TestCase
from django.urls import reverse
from rest_framework.test import APIClient, APITestCase

from authentication.models import User

import os

# Create your tests here.


class TestTestCase(APITestCase):
    def setUp(self):
        self.staff_user = User.objects.create(
            email="test@account.me", is_staff=True, is_active=True
        )
        self.staff_user_password = "staff_password"
        self.staff_user.set_password(self.staff_user_password)

    def test_testing(self):
        print(User.objects.all())
        url = reverse("public staff user", kwargs={"email": self.staff_user.email})
        print(url)

        response = self.client.get(
            url,
        )
        print(response.content)

I have a few unused imports, but those don't matter. I create a User instance, and change it's password. Then, in the test, I try to retrieve it's data.

I can confirm the user exists (the shell returns <QuerySet [<User: Employee#000>]>) and the url works (/api/user/test@account.me/ works with another email in the dev database).

However, response.content returns the following:

# Escaped for ease of reading
b'\n<!doctype html>\n<html lang="en">\n<head>\n
  <title>Not Found</title>\n</head>\n<body>\n
  <h1>Not Found</h1>
<p>The requested resource was not found on this server.</p>
\n</body>\n</html>\n'

I confirmed that the client can access any url, whether reversed or hard-coded. Can't POST or PATCH to anything either.

I've been scratching my head for a while now, but I can't find what I'm missing

Edit 1: I've added an edited version of the view. The logic is the same, but I'm not allowed to share the exact code.

Edit 2: I get the UserModel from Django's get_user_model. Added clarification

Edit 3: format='json' does not change anything

`urlpatters` is a typo - you won't get any paths matching! Change it to `urlpatterns` :) — michjnich, Apr 21 '21 at 10:23
@michjnich typo while transcribing, but it's OK in the project — Xceptional Bro, Apr 21 '21 at 10:28
@XceptionalBro you have used `UserModel` in the view and `User` in your test. Is this the problem or is it another transcribing error? If it is a transcribing error, please see how to write a [mre] (your given example should be able to reproduce the problem, and also no other errors should arise than the one you talk about). — Abdul Aziz Barkat, Apr 21 '21 at 10:40
The inheriting from multiple views is a little odd ... inherit from `GenericAPIView` and use mixins if you need to, — michjnich, Apr 21 '21 at 10:42
@AbdulAzizBarkat I'm using Django's get_user_model and not importing User directly in the view. Editing now — Xceptional Bro, Apr 21 '21 at 10:42
@michjnich That view was one of the first I wrote, and I was a bit rusty. I admit it's weird, and I have to change it, but it works — Xceptional Bro, Apr 21 '21 at 10:43
@michjnich changed to mixins. Same functionality, and same error. Working just fine in the browser, "Not Found" while testing — Xceptional Bro, Apr 21 '21 at 10:49
@michjnich English ain't my native language, so I don't get what "clipped code" means. However, you're, this endpoint is open. — Xceptional Bro, Apr 21 '21 at 11:05
Maybe use the DRF test classes? https://www.django-rest-framework.org/api-guide/testing/ — michjnich, Apr 21 '21 at 11:20
@michjnich I'm using DRF's APITestCase, wouldn't that suffice? — Xceptional Bro, Apr 21 '21 at 11:31
Does it need `format='json'` maybe? Running out of ideas here ... what renderers do you have set in `settings.py`? — michjnich, Apr 21 '21 at 11:37
@michjnich Just tried with `format="json"`, same error. I ran out of ideas a while ago — Xceptional Bro, Apr 21 '21 at 11:39
The class itself is `HttpResponseNotFound`, with representation ``, if it helps — Xceptional Bro, Apr 21 '21 at 12:06
try adding `format="json"` to the `self.client.get(`, maybe there's a configuration problem — pleasedontbelong, Apr 21 '21 at 12:18
ran out of ideas... my suggestion: add a `import ipdb;ipdb.set_trace()` before the call and debug step by step — pleasedontbelong, Apr 21 '21 at 13:59
Finally got it sorted out! But I'll try that snippet next time it get stuck, seems useful, thanks! — Xceptional Bro, Apr 21 '21 at 14:03

Xceptional Bro · Answer 1 · 2021-04-21T14:21:54.993

OMG. I didn't fix it, but I found a workaround. For everyone going through the same hell as me, here's a possible fix.

You're gonna want to use a Factory instead of a Client. APIRequestFactory works just fine
The Client couldn't find the view, but reverse and resolve are able. So you need to get the view function from those.
Finally, you're gonna want to generate a request using the Factory, and a response using the view function

Working example:

from django.urls import reverse, resolve
from rest_framework.test import APIRequestFactory, APITestCase

from yourapp import models

class TestTestCase(APITestCase):
    def setUp(self):
        self.staff_user = models.YourModel.objects.create(**yourdata)

    def test_testing(self):
        factory = APIRequestFactory()
        url = reverse("your reverse url name", kwargs=kwargs)
        sol = resolve(url)
        view = sol.func

        request = f.get(url) # works with every method
        response = view(request, **kwargs)
        response.render()
        print(response.content) # Finally! Response, my beloved!

Worst this about this workaround is that I need to pass the kwargs twice. I'll end up making a helper method and done

It wasn't exactly what I was looking for but your code did help me remember why I kept getting this same error ... doh! — Harlin, Dec 08 '21 at 21:55

score 0 · Answer 2 · answered Dec 08 '21 at 21:54

Sometimes you can get this error if you are using:

response = client.get('my-view-name', args=[0, 1])

instead of ...

response = client.get(reverse('my-view-name', args=[0, 1]))

Moral: make sure you use reverse() from django.urls. Hope this might help someone frantically searching for the answer who may have come here searching the exact error but context is a little different.

Django is always returning 404 while testing. "The requested resource was not found on this server."

2 Answers2