Disallow DELETE on a notification_template

When there are pending notifications

awx/api/views.py

@@ -3487,6 +3487,15 @@ class NotificationTemplateDetail(RetrieveUpdateDestroyAPIView):
     serializer_class = NotificationTemplateSerializer
     new_in_300 = True
 
+    def delete(self, request, *args, **kwargs):
+        obj = self.get_object()
+        if not request.user.can_access(self.model, 'delete', obj):
+            return Response(status=status.HTTP_404_NOT_FOUND)
+        if obj.notifications.filter(status='pending').exists():
+            return Response({"error": "Delete not allowed while there are pending notifications"},
+                            status=status.HTTP_405_METHOD_NOT_ALLOWED)
+        return resp
+
 class NotificationTemplateTest(GenericAPIView):
 
     view_name = 'NotificationTemplate Test'

awx/main/tests/functional/test_notifications.py

@@ -1,7 +1,7 @@
 import mock
 import pytest
 
-from awx.main.models.notifications import NotificationTemplate
+from awx.main.models.notifications import NotificationTemplate, Notification
 from awx.main.models.inventory import Inventory, Group
 from awx.main.models.jobs import JobTemplate
 
@@ -112,3 +112,13 @@ def test_notification_template_simple_patch(patch, notification_template, admin)
 @pytest.mark.django_db
 def test_notification_template_invalid_notification_type(patch, notification_template, admin):
     patch(reverse('api:notification_template_detail', args=(notification_template.id,)), { 'notification_type': 'invalid'}, admin, expect=400)
+
+@pytest.mark.django_db
+def test_disallow_delete_when_notifications_pending(delete, user, notification_template):
+    u = user('superuser', True)
+    url = reverse('api:notification_template_detail', args=(notification_template.id,))
+    n = Notification.objects.create(notification_template=notification_template,
+                                    status='pending')
+    response = delete(url, user=u)
+    assert response.status_code == 405
+