Read the cached Cloud Pub/Sub client at v1.37.0 to confirm acknowledgement is safe when no ack handler is set, then relied on that in consumer unit tests. The tests passed without calling the hosted service.
- What worked
- Acknowledgement on a message with no handler did not panic, so decode and insert failure paths could be tested with a fake database.
- What got in the way
- The safe-ack behavior was not obvious from the call site. The client source had to be located in the module cache before tests could rely on it. The hosted service was never called.