fix(events): keep registration status reads nonblocking

apps/events/tests/integration/test_event_models.py

@@ -4,8 +4,9 @@ from datetime import timedelta
 from django.contrib import admin
 from django.utils import timezone
 from apps.events.admin import EventAdmin, RegistrationAdmin
-from apps.events.models import Event, Registration
+from apps.events.models import Event, Registration, RegistrationNotification
 from apps.events.tasks import send_registration_cancellation_notification, send_registration_confirmation_notification
+from apps.events.tasks import deliver_pending_registration_notifications
 from apps.users.models import User
 
 @pytest.mark.django_db
@@ -25,10 +26,33 @@ class TestEventModelTests:
 
     def test_capacity_counts_confirmed_registration(self, mocker):
         delay = mocker.patch('apps.events.tasks.send_registration_confirmation_notification.delay')
-        Registration.objects.create(event=self.event, user=self.user, status=Registration.StatusChoices.CONFIRMED)
+        registration = Registration.objects.create(event=self.event, user=self.user, status=Registration.StatusChoices.CONFIRMED)
         assert self.event.current_attendees_count == 1
         assert not self.event.has_available_slots
-        delay.assert_called_once()
+        assert RegistrationNotification.objects.filter(
+            registration=registration, kind=RegistrationNotification.Kind.CONFIRMED,
+        ).exists()
+        delay.assert_not_called()
+
+    def test_notification_worker_retries_after_redis_failure(self, mocker):
+        registration = Registration.objects.create(
+            event=self.event, user=self.user, status=Registration.StatusChoices.CONFIRMED,
+        )
+        entry = RegistrationNotification.objects.get(registration=registration)
+        notify = mocker.patch("apps.events.tasks.notify_user", side_effect=ConnectionError("redis unavailable"))
+
+        assert deliver_pending_registration_notifications() == 0
+        entry.refresh_from_db()
+        assert entry.delivered_at is None
+
+        notify.side_effect = None
+        assert deliver_pending_registration_notifications() == 1
+        entry.refresh_from_db()
+        registration.refresh_from_db()
+        assert entry.delivered_at is not None
+        assert registration.confirmation_notification_sent_at is not None
+        assert notify.call_args.args[1]["id"] == f"registration-{entry.pk}-confirmed"
+        assert deliver_pending_registration_notifications() == 0
 
     def test_unlimited_capacity_allows_registration(self):
         self.event.capacity = None