Django Rest Framework URL for custom action not working - django

Question

I've got the following custom action in my view:
class OrderAPIViewSet(viewsets.ViewSet):
def create(self, request):
print("Here: working")
#action(detail=True, methods=['post'])
def add(self, request, *arg, **kwargs):
print("HERE in custom action")
order = self.get_object()
print(order)
my app's urls.py is:
from rest_framework import routers
from .views import OrderAPIViewSet
router = routers.DefaultRouter()
router.register(r'orders', OrderAPIViewSet, basename='order')
urlpatterns = router.urls
So in my test when I try to access orders/post it works, but when I try to access orders/{pk}/add it fails. I mean, the reverse itself is failing:
ORDERS_LIST_URL = reverse('order-list')
ORDERS_ADD_URL = reverse('order-add')
class PublicOrderApiTests(TestCase):
def test_sample_test(self):
data = {}
res = self.client.post(ORDERS_ADD_URL, data, format='json')
as I said before, I've got a separate test where I use ORDERS_LIST_URL like this:
res = self.client.post(ORDERS_LIST_URL, data, format='json')
but when running the test I'm getting the following error:
ImportError: Failed to import test module: orders.tests Traceback
(most recent call last): File
"/usr/local/lib/python3.7/unittest/loader.py", line 436, in
_find_test_path
module = self._get_module_from_name(name) File "/usr/local/lib/python3.7/unittest/loader.py", line 377, in
_get_module_from_name
import(name) File "/app/orders/tests.py", line 22, in
ORDERS_ADD_URL = reverse('order-add') File "/usr/local/lib/python3.7/site-packages/django/urls/base.py", line 87,
in reverse
return iri_to_uri(resolver._reverse_with_prefix(view, prefix, *args, **kwargs)) File "/usr/local/lib/python3.7/site-packages/django/urls/resolvers.py",
line 685, in _reverse_with_prefix
raise NoReverseMatch(msg) django.urls.exceptions.NoReverseMatch: Reverse for 'order-add' with no arguments not found. 2 pattern(s)
tried: ['orders/(?P[^/.]+)/add\.(?P[a-z0-9]+)/?$',
'orders/(?P[^/.]+)/add/$']
---------------------------------------------------------------------- Ran 1 test in 0.000s
FAILED (errors=1)
according to the documentation I shouldn't need to register this endpoint, the router is supposed to do it by itself. What am I missing?

Answer 1

The first thing that you've missed is pk in your reverse. Since the add API needs a pk of your Order object, you need to pass it to reverse function. For example:
order_add_url = reverse('order-add', kwargs={'pk': 1})
print(order_add_url) # which will print '/orders/1/add/'
So I think you should move this part to the body of PublicOrderApiTests's methods since you need a dynamic url per test object.
Another problem is that the ViewSet class does not support self.get_object() and if you want to use this method you should either have your own method or use rest framework GenericViewSet (i.e. from rest_framework.viewsets import GenericViewSet and inherit from this class instead of ViewSet) then you can access the get_object() method. You can also read more about generic views in rest framework docs.