Module testing 

In-process test broker, behind the testing feature.

KafkaTestBroker follows the same ladder as the real broker and implements the core TestableBroker contract on its connected form, over an in-memory router, so application handlers wired against Kafka descriptors can be exercised without a cluster: messages fan out synchronously to subscribers matched by exact topic name. The real KafkaPublish policy pairs against it too, so include sites need no test-only variant.

Scope: topic-name routing, settlement, headers, and the partition-key header. Consumer groups, partitions, committed offsets, start offsets, rebalancing, and everything transactional (transactions and the exactly-once pipeline) are transport behavior; exercise them against a real cluster (see the crate’s integration tests and KAFKA_TEST_URL).

Structs

ConnectedKafkaTestBroker

The connected form of KafkaTestBroker.

KafkaTestBroker

In-process broker for application tests: same descriptors, no Kafka cluster.

KafkaTestMessage

One in-process delivery.

KafkaTestPublisher

Publisher into the in-process router.

KafkaTestSubscriber

In-process subscriber on one topic name.