fix permanent notification callback

com/models.py

@@ -160,9 +160,12 @@ class News(models.Model):
         )
 
 
-def news_notification_callback(notif):
+def news_notification_callback(notif: Notification):
+    # the NewsDate linked to the News
+    # which creation triggered this callback may not exist yet,
+    # so it's important to filter by "not past date" rather than by "future date"
     count = News.objects.filter(
-        dates__start_date__gt=timezone.now(), is_published=False
+        ~Q(dates__start_date__gt=timezone.now()), is_published=False
     ).count()
     if count:
         notif.viewed = False

com/tests/test_notifications.py

@@ -0,0 +1,23 @@
+import pytest
+from django.conf import settings
+from model_bakery import baker
+
+from com.models import News
+from core.models import Group, Notification, User
+
+
+@pytest.mark.django_db
+def test_notification_created():
+    com_admin_group = Group.objects.get(pk=settings.SITH_GROUP_COM_ADMIN_ID)
+    com_admin_group.users.all().delete()
+    Notification.objects.all().delete()
+    com_admin = baker.make(User, groups=[com_admin_group])
+    for i in range(2):
+        # news notifications are permanent, so the notification created
+        # during the first iteration should be reused during the second one.
+        baker.make(News)
+        notifications = list(Notification.objects.all())
+        assert len(notifications) == 1
+        assert notifications[0].user == com_admin
+        assert notifications[0].type == "NEWS_MODERATION"
+        assert notifications[0].param == str(i + 1)