Provide a JUnit 5 extension equivalent of EmbeddedKafkaRule

[wilkinsona]

For those that wish to use JUnit 5, it would be helpful to have a JUnit 5 extension that is the equivalent of EmbeddedKafkaRule. Spring Boot 2.2 is switching to using JUnit 5 by default in spring-boot-starter-test while including the Vintage Engine to allow JUnit 4 to be used during a migration period. This means that Boot 2.2 users will be able to use EmbeddedKafkaRule but it may prevent a complete migration to JUnit 5.

[garyrussell]

JUnit5 is already supported via the @EmbeddedKafka test annotation.

[artembilan]

I think our @EmbeddedKafka meets all the requirements for JUnit 5 with Spring:

@SpringJUnitConfig
@DirtiesContext
@EmbeddedKafka
public class KafkaStreamsCustomizerTests {
...
}

Or is your idea to really have a fully blown JUnit 5 extension, so we don't need requiring Spring Test environment?

[wilkinsona]

I was looking for a replacement for this style of usage of EmbeddedKafkaRule. I don't think @EmbeddedKafka fits the bill there, does it?

[garyrussell]

All @EmbeddedKafka does is add a @Bean to the test config.

You can simply add a EmbeddedKafkaBroker @Bean to KafkaConfig there.

But, I agree, it would be more convenient to add more formal JUnit support.

[garyrussell]

@wilkinsona spring-projects/spring-boot#17034