Mocking isolates a service from external dependencies during unit testing. A mock producer or consumer replaces Kafka infrastructure so tests can focus on observable behavior, such as returned values, side effects, or expected producer calls. section 10.3.1
Use mocking to:
- Verify that a service passes the correct data to a Kafka producer. section 10.3.1
- Invoke a consumer handler with a deserialized message and inspect downstream side effects or state changes. section 10.3.1
- Keep unit tests independent of a Kafka cluster and real network communication. section 10.3.1
Figure 10.6 Unit testing Kafka components using mock implementations. The services are tested in isolation by replacing the actual Kafka producer and consumer with mocks. This allows the test logic to focus on verifying functional behavior without involving a Kafka cluster or real network communication.
Shows services tested in isolation by replacing real Kafka producers and consumers with mock implementations. section 10.3.1
