Simple embedded Kafka test example with spring boot

Embedded Kafka tests work for me with below configs,

Annotation on test class

@EnableKafka
@SpringBootTest(classes = {KafkaController.class}) // Specify @KafkaListener class if its not the same class, or not loaded with test config
@EmbeddedKafka(
    partitions = 1, 
    controlledShutdown = false,
    brokerProperties = {
        "listeners=PLAINTEXT://localhost:3333", 
        "port=3333"
})
public class KafkaConsumerTest {
    @Autowired
    KafkaEmbedded kafkaEmbeded;

    @Autowired
    KafkaListenerEndpointRegistry kafkaListenerEndpointRegistry;

Before annotation for setup method

@Before
public void setUp() throws Exception {
  for (MessageListenerContainer messageListenerContainer : kafkaListenerEndpointRegistry.getListenerContainers()) {
    ContainerTestUtils.waitForAssignment(messageListenerContainer, 
    kafkaEmbeded.getPartitionsPerTopic());
  }
}

Note: I am not using @ClassRule for creating embedded Kafka rather auto-wiring
@Autowired embeddedKafka

@Test
public void testReceive() throws Exception {
     kafkaTemplate.send(topic, data);
}

Hope this helps!

Edit: Test configuration class marked with @TestConfiguration

@TestConfiguration
public class TestConfig {

@Bean
public ProducerFactory<String, String> producerFactory() {
    return new DefaultKafkaProducerFactory<>(KafkaTestUtils.producerProps(kafkaEmbedded));
}

@Bean
public KafkaTemplate<String, String> kafkaTemplate() {
    KafkaTemplate<String, String> kafkaTemplate = new KafkaTemplate<>(producerFactory());
    kafkaTemplate.setDefaultTopic(topic);
    return kafkaTemplate;
}

Now @Test method will autowire KafkaTemplate and use is to send message

kafkaTemplate.send(topic, data);

Updated answer code block with above line