Alpakka Kafka test Transactional stream


Is there a concrete example of testing Alpakka-Kafka transactional stream. I have a stream which implements consume-transform-produce flow, which works fine via Main class, but I am not able to test it via test-containers.

My testing strategy is to send messages to ingress topic, then I have created a consumer for egress topic and expect to receive the transformed messages, I can see logs that messages getting transformed but egress consumer doesn’t receive any message.

Any idea what’s going on?