Running test together fails, running test alone succeeds - django

Question

I'm using pytest.
Going through the tests with a debugger, running both test_joining_previously_entered_queue_returns_previous_queue_details and test_joining_queue_enters_correct_position together, test_joining_previously_entered_queue_returns_previous_queue_details succeeds but test_joining_queue_enters_correct_position fails at queue = get_object_or_404(Queue, pk=kwargs["pk"]) in the JoinQueue view, where the view throws a 404
If I run test_joining_previously_entered_queue_returns_previous_queue_details individually, then the test will pass no problem.
What should happen is that create_company_one creates a Company object, which in turn creates a Queue object (shown in the overridden save method of Company). The associated Queue object does not seem to be created if test_joining_queue_enters_correct_position is run with the other test, but works if the test is run standalone
Why does this happen and how can I fix it?
test_join_queue.py
def create_company_one():
return Company.objects.create(name='kfc')
#pytest.mark.django_db
def test_joining_previously_entered_queue_returns_previous_queue_details(authenticated_client: APIClient):
create_company_one()
url = reverse('user-queue-join', args=[1])
first_response = authenticated_client.put(url)
first_data = first_response.data
second_response = authenticated_client.put(url)
second_data = second_response.data
assert first_data == second_data
#pytest.mark.django_db
def test_joining_queue_enters_correct_position(factory: APIRequestFactory):
"""
Makes sure that whenever a user joins a queue, their position is sorted correctly
based on WHEN they joined. Since all users in self.users join the queue
in a time canonical manner, we can iterate over them to test for their queue positions.
"""
create_company_one()
users = create_users()
view = JoinQueue.as_view()
url = reverse('user-queue-join',args=[1])
request = factory.put(url)
for queue_position, user in enumerate(users):
force_authenticate(request, user=user)
response = view(request, pk=1)
assert response.data["position"] == queue_position + 1
views.py
class JoinQueue(APIView):
permission_classes = [IsAuthenticated]
def put(self, request, *args, **kwargs):
# throws 404 here
queue = get_object_or_404(Queue, pk=kwargs["pk"])
user = request.user
try:
queue_details_of_a_user = user.queue_details.get(queue=queue)
except ObjectDoesNotExist:
queue_details_of_a_user = QueueDetails.objects.create(user=user, queue=queue)
serializer = QueueDetailsSerializer(queue_details_of_a_user)
return Response(serializer.data)
else:
serializer = QueueDetailsSerializer(queue_details_of_a_user)
return Response(serializer.data)
models.py
class Company(models.Model):
name = models.CharField(max_length=15, unique=True)
def save(self, *args: Any, **kwargs: Any) -> None:
created = bool(self.pk)
super().save(*args, **kwargs)
if not created:
Queue.objects.create(company=self)
logging.info(f"{self.name} has created its queue")
return None
def __str__(self) -> str:
return self.name
class Queue(models.Model):
company = models.OneToOneField(
Company, on_delete=models.CASCADE, related_name="queue"
)
users = models.ManyToManyField(User, through="QueueDetails", related_name="queues")
#property
def length(self) -> int:
return len(self.users.all())
#property
def sorted_users(self) -> "QuerySet[User]":
return self.users.all().order_by("queue_details__joined_at")
def __str__(self) -> str:
return f"{self.company}'s queue"
class QueueDetails(models.Model):
joined_at = models.DateTimeField(auto_now_add=True)
queue = models.ForeignKey(
Queue,
related_name="queue_details",
on_delete=models.CASCADE,
)
user = models.ForeignKey(
User,
related_name="queue_details",
on_delete=models.CASCADE,
)
#property
def position(self) -> int:
for index, user in enumerate(self.queue.sorted_users):
if user == self.user:
return index + 1
raise ValueError("User is not in the queue, Invalid queue position")