Check for suspension before sending a broadcast

This mirrors the check we do for jobs, which are also a high-impact
task [1]. While this shouldn't be possible, just like other checks
we're adding it here to be doubly certain.

[1]: 3d71815956/app/celery/tasks.py (L74)

app/celery/broadcast_message_tasks.py

@@ -56,6 +56,12 @@ def check_provider_message_should_send(broadcast_event, provider):
     4. If you need to re-send this task off again, you'll need to run the following command on paas:
        `send_broadcast_provider_message.apply_async(args=(broadcast_event_id, provider), queue=QueueNames.BROADCASTS)`
     """
+    if not broadcast_event.service.active:
+        raise BroadcastIntegrityError(
+            f'Cannot send broadcast_event {broadcast_event.id} ' +
+            f'to provider {provider}: the service is suspended'
+        )
+
     current_provider_message = broadcast_event.get_provider_message(provider)
     # if this is the first time a task is being executed, it won't have a provider message yet
     if current_provider_message and current_provider_message.status != BroadcastProviderMessageStatus.SENDING:

tests/app/celery/test_broadcast_message_tasks.py

@@ -735,6 +735,19 @@ def test_check_provider_message_should_send_raises_if_current_event_already_has_
     check_provider_message_should_send(current_event, 'ee')
 
 
+def test_check_provider_message_should_send_raises_if_service_is_suspended(
+    sample_broadcast_service,
+):
+    sample_broadcast_service.active = False
+    broadcast_message = create_broadcast_message(service=sample_broadcast_service, content='test')
+    current_event = create_broadcast_event(broadcast_message, message_type='alert')
+
+    with pytest.raises(BroadcastIntegrityError) as exc:
+        check_provider_message_should_send(current_event, 'ee')
+
+    assert 'service is suspended' in str(exc.value)
+
+
 def test_send_broadcast_provider_message_does_nothing_if_cbc_proxy_disabled(mocker, notify_api, sample_template):
     mock_proxy_client_getter = mocker.patch(
         'app.celery.broadcast_message_tasks.cbc_proxy_client',