UserKafkaProducerTest.java

class UserKafkaProducerTest {
  @Test
  void testWriteToKafka() throws InterruptedException, JsonProcessingException {
      // Create a user and write to Kafka
      User user = new User("11111", "John", "Wick");
      producer.writeToKafka(user);

      // Read the message (John Wick user) with a test consumer from Kafka and assert its properties
      ConsumerRecord<String, String> message = records.poll(500, TimeUnit.MILLISECONDS);
      assertNotNull(message);
      assertEquals("11111", message.key());
      User result = objectMapper.readValue(message.value(), User.class);
      assertNotNull(result);
      assertEquals("John", result.getFirstName());
      assertEquals("Wick", result.getLastName());
  }
}