Check if a service is live before sending a broadcast

We only want to send a broadcast if the broadcast message is not stubbed
and the service is live at the point at which the broadcast event should
be created. This is to prevent the situation where a broadcast service is
switched to live / trial mode in between the message being created and
approved (we log an error if this happens).

A stubbed broadcast message with a trial mode service at the point of
approval is not an issue - trial mode services can approve their own
broadcasts. In this situation, we don't create the broadcast event but
also don't need to log an error.

app/broadcast_message/rest.py

@@ -190,16 +190,19 @@ def update_broadcast_message_status(service_id, broadcast_message_id):
 
 def _create_broadcast_event(broadcast_message):
     """
-    Creates a broadcast event, stores it in the database, and triggers the task to send the CAP XML off
+    If the service is live and the broadcast message is not stubbed, creates a broadcast event, stores it in the
+    database, and triggers the task to send the CAP XML off.
     """
-    if not broadcast_message.stubbed:
+    service = broadcast_message.service
+
+    if not broadcast_message.stubbed and not service.restricted:
         msg_types = {
             BroadcastStatusType.BROADCASTING: BroadcastEventMessageType.ALERT,
             BroadcastStatusType.CANCELLED: BroadcastEventMessageType.CANCEL,
         }
 
         event = BroadcastEvent(
-            service=broadcast_message.service,
+            service=service,
             broadcast_message=broadcast_message,
             message_type=msg_types[broadcast_message.status],
             transmitted_content={"body": broadcast_message.content},
@@ -219,3 +222,11 @@ def _create_broadcast_event(broadcast_message):
             kwargs={'broadcast_event_id': str(event.id)},
             queue=QueueNames.BROADCASTS
         )
+    elif broadcast_message.stubbed != service.restricted:
+        # It's possible for a service to create a broadcast in trial mode, and then approve it after the
+        # service is live (or vice versa). We don't think it's safe to send such broadcasts, as the service
+        # has changed since they were created. Log an error instead.
+        current_app.logger.error(
+            f'Broadcast event not created. Stubbed status of broadcast message was {broadcast_message.stubbed}'
+            f' but service was {"in trial mode" if service.restricted else "live"}'
+        )

tests/app/broadcast_message/test_rest.py

@@ -1,5 +1,4 @@
 import uuid
-from unittest.mock import ANY
 
 import pytest
 from freezegun import freeze_time
@@ -562,23 +561,32 @@ def test_update_broadcast_message_status_stores_approved_by_and_approved_at_and_
     assert alert_event.transmitted_content == {"body": "emergency broadcast"}
 
 
-def test_update_broadcast_message_status_updates_details_but_does_not_queue_task_for_stubbed_broadcast_message(
+@pytest.mark.parametrize('broadcast_message_stubbed, service_restricted_before_approval', [
+    (True, True),
+    (True, False),
+    (False, True),
+])
+def test_update_broadcast_message_status_updates_details_but_does_not_queue_task_if_bm_is_stubbed_or_service_not_live(
     admin_request,
     sample_broadcast_service,
-    mocker
+    mocker,
+    broadcast_message_stubbed,
+    service_restricted_before_approval,
 ):
-    sample_broadcast_service.restricted = True
+    sample_broadcast_service.restricted = broadcast_message_stubbed
     t = create_template(sample_broadcast_service, BROADCAST_TYPE, content='emergency broadcast')
     bm = create_broadcast_message(
         t,
         status=BroadcastStatusType.PENDING_APPROVAL,
         areas={"areas": ["london"], "simple_polygons": [[[51.30, 0.7], [51.28, 0.8], [51.25, -0.7]]]},
-        stubbed=True
+        stubbed=broadcast_message_stubbed
     )
     approver = create_user(email='approver@gov.uk')
     sample_broadcast_service.users.append(approver)
     mock_task = mocker.patch('app.celery.broadcast_message_tasks.send_broadcast_event.apply_async')
 
+    sample_broadcast_service.restricted = service_restricted_before_approval
+
     response = admin_request.post(
         'broadcast_message.update_broadcast_message_status',
         _data={'status': BroadcastStatusType.BROADCASTING, 'created_by': str(approver.id)},
@@ -707,7 +715,7 @@ def test_update_broadcast_message_status_allows_trial_mode_services_to_approve_o
     assert response['approved_at'] is not None
     assert response['created_by_id'] == str(t.created_by_id)
     assert response['approved_by_id'] == str(t.created_by_id)
-    mock_task.assert_called_once_with(kwargs={'broadcast_event_id': ANY}, queue='broadcast-tasks')
+    assert not mock_task.called
 
 
 def test_update_broadcast_message_status_rejects_approval_from_user_not_on_that_service(