`@EmbeddedKafkaRule` to `@EmbeddedKafka` test conversion

[pway99]

@EmbeddedKafkaRule to @EmbeddedKafka for JUnit 5 tests migration recipe.

https://docs.spring.io/spring-kafka/docs/current/api/org/springframework/kafka/test/context/EmbeddedKafka.html https://blog.mimacom.com/testing-apache-kafka-with-spring-boot-junit5/

[pway99]

example from spring-batch KafkaItemReaderTests.

1. remove EmbeddedKafkaRule
2. add class annotations @EmbeddedKafka @ExtendWith(SpringExtension.class) @TestInstance(TestInstance.Lifecycle.PER_CLASS)
3. add @Autowired private EmbeddedKafkaBroker embeddedKafkaBroker;
4. remove static modifier from setup() method (note. @TestInstance annotation).
5. replace embeddedKafka.getEmbeddedKafka() with embeddedKafkaBroker

before:

public class KafkaItemReaderTests {

	@ClassRule
	public static EmbeddedKafkaRule embeddedKafka = new EmbeddedKafkaRule(1);

	private KafkaItemReader<String, String> reader;
	private KafkaTemplate<String, String> template;
	private Properties consumerProperties;

	@BeforeClass
	public static void setUpTopics() {
		embeddedKafka.getEmbeddedKafka().addTopics(
				new NewTopic("topic1", 1, (short) 1),
				new NewTopic("topic2", 2, (short) 1),
				new NewTopic("topic3", 1, (short) 1),
				new NewTopic("topic4", 2, (short) 1),
				new NewTopic("topic5", 1, (short) 1),
				new NewTopic("topic6", 1, (short) 1)
		);
	}

	@Before
	public void setUp() {
		Map<String, Object> producerProperties = KafkaTestUtils.producerProps(embeddedKafka.getEmbeddedKafka());
		ProducerFactory<String, String> producerFactory = new DefaultKafkaProducerFactory<>(producerProperties);
		this.template = new KafkaTemplate<>(producerFactory);

		this.consumerProperties = new Properties();
		this.consumerProperties.setProperty(ConsumerConfig.BOOTSTRAP_SERVERS_CONFIG,
				embeddedKafka.getEmbeddedKafka().getBrokersAsString());
		this.consumerProperties.setProperty(ConsumerConfig.GROUP_ID_CONFIG, "1");
		this.consumerProperties.setProperty(ConsumerConfig.KEY_DESERIALIZER_CLASS_CONFIG,
				StringDeserializer.class.getName());
		this.consumerProperties.setProperty(ConsumerConfig.VALUE_DESERIALIZER_CLASS_CONFIG,
				StringDeserializer.class.getName());
	}
}

after:

@EmbeddedKafka
@ExtendWith(SpringExtension.class)
@TestInstance(TestInstance.Lifecycle.PER_CLASS)
public class KafkaItemReaderTests {

	@Autowired
	private EmbeddedKafkaBroker embeddedKafkaBroker;

	private KafkaItemReader<String, String> reader;
	private KafkaTemplate<String, String> template;
	private Properties consumerProperties;

	@BeforeAll
	public void setUpTopics() {
		embeddedKafkaBroker.addTopics(
				new NewTopic("topic1", 1, (short) 1),
				new NewTopic("topic2", 2, (short) 1),
				new NewTopic("topic3", 1, (short) 1),
				new NewTopic("topic4", 2, (short) 1),
				new NewTopic("topic5", 1, (short) 1),
				new NewTopic("topic6", 1, (short) 1)
		);
	}

	@BeforeEach
	public void setUp() {
		Map<String, Object> producerProperties = KafkaTestUtils.producerProps(embeddedKafkaBroker);
		ProducerFactory<String, String> producerFactory = new DefaultKafkaProducerFactory<>(producerProperties);
		this.template = new KafkaTemplate<>(producerFactory);

		this.consumerProperties = new Properties();
		this.consumerProperties.setProperty(ConsumerConfig.BOOTSTRAP_SERVERS_CONFIG,
				embeddedKafkaBroker.getBrokersAsString());
		this.consumerProperties.setProperty(ConsumerConfig.GROUP_ID_CONFIG, "1");
		this.consumerProperties.setProperty(ConsumerConfig.KEY_DESERIALIZER_CLASS_CONFIG,
				StringDeserializer.class.getName());
		this.consumerProperties.setProperty(ConsumerConfig.VALUE_DESERIALIZER_CLASS_CONFIG,
				StringDeserializer.class.getName());
	}
}