fix: changes count_by_app_name in counts api to return apps with zero… (

openedx#32629)

* fix: changes count_by_app_name in counts api to return apps with zero unseen count

* refactor: initialised count_by_app_name_dict with zeros

openedx/core/djangoapps/notifications/tests/test_views.py

@@ -496,7 +496,8 @@ def test_get_unseen_notifications_count_with_show_notifications_tray(self, show_
 
             self.assertEqual(response.status_code, 200)
             self.assertEqual(response.data['count'], 4)
-            self.assertEqual(response.data['count_by_app_name'], {'App Name 1': 2, 'App Name 2': 1, 'App Name 3': 1})
+            self.assertEqual(response.data['count_by_app_name'], {
+                'App Name 1': 2, 'App Name 2': 1, 'App Name 3': 1, 'discussion': 0})
             self.assertEqual(response.data['show_notifications_tray'], show_notifications_tray_enabled)
 
     def test_get_unseen_notifications_count_for_unauthenticated_user(self):
@@ -517,7 +518,7 @@ def test_get_unseen_notifications_count_for_user_with_no_notifications(self):
 
         self.assertEqual(response.status_code, 200)
         self.assertEqual(response.data['count'], 0)
-        self.assertEqual(response.data['count_by_app_name'], {})
+        self.assertEqual(response.data['count_by_app_name'], {'discussion': 0})
 
 
 class MarkNotificationsSeenAPIViewTestCase(APITestCase):

openedx/core/djangoapps/notifications/views.py

@@ -289,8 +289,11 @@ def get(self, request):
             .annotate(count=Count('*'))
         )
         count_total = 0
-        count_by_app_name_dict = {}
         show_notifications_tray_enabled = False
+        count_by_app_name_dict = {
+            app_name: 0
+            for app_name in COURSE_NOTIFICATION_APPS
+        }
 
         for item in count_by_app_name:
             app_name = item['app_name']