pytest assertion helper

test_users_url.py

from operator import itemgetter

import pytest

from django.urls import reverse
from django.contrib.auth.models import User
from rest_framework import status


def assert_response_userlist_equals(response, users):
    __tracebackhide__ = True
    result = response.json()
    assert isinstance(
        result, list), f'Result is of type {type(result)}. Expected <list>'
    assert len(users) == len(
        result
    ), f'Result contains {len(result)} item(s). Expected {len(users)} item(s)'
    expected_items = [{
        'username': u.username,
        'email': u.email,
        'is_staff': u.is_staff,
        'url': f'http://testserver/users/{u.id}/',
    } for u in users]
    expected_items.sort(key=itemgetter('url'))
    result.sort(key=itemgetter('url'))
    assert result == expected_items


@pytest.fixture
def given_user_1():
    user = User.objects.create(username='user1')
    yield user
    user.delete()


@pytest.fixture
def given_user_2():
    user = User.objects.create(username='user2')
    yield user
    user.delete()


@pytest.fixture
def given_user_model_is_empty():
    User.objects.all().delete()


@pytest.fixture
def given_user_model_has_two_users(request):
    request.getfixturevalue('given_user_model_is_empty')
    return [
        request.getfixturevalue('given_user_1'),
        request.getfixturevalue('given_user_2')
    ]


@pytest.mark.django_db
def test_should_return_list_of_users(client, request):
    given_users = request.getfixturevalue('given_user_model_has_two_users')
    # When get user-list endpoint is executed
    url = reverse('user-list')
    response = client.get(url)
    # Then request is successfull
    assert response.status_code == status.HTTP_200_OK
    # And response matches expected
    assert_response_userlist_equals(response, given_users)