如何为@KafkaListener 编写单元测试？

Question

试图弄清楚我是否可以使用 spring-kafka 和 spring-kafka-test 为 @KafkaListener 编写单元测试。

我的听众课。

    public class MyKafkaListener {
    @Autowired
    private MyMessageProcessor myMessageProcessor;

    @KafkaListener(topics = "${kafka.topic.01}", groupId = "SF.CLIENT", clientIdPrefix = "SF.01", containerFactory = "myMessageListenerContainerFactory")
    public void myMessageListener(MyMessage message) {
        myMessageProcessor.process(message);
        log.info("MyMessage processed");
    }}

我的测试课：

    @RunWith(SpringRunner.class)
    @DirtiesContext
    @EmbeddedKafka(partitions = 1, topics = {"I1.Topic.json.001"})
    @ContextConfiguration(classes = {TestKafkaConfig.class})
    public class MyMessageConsumersTest {

    @Autowired
    private MyMessageProcessor myMessageProcessor;

    @Value("${kafka.topic.01}")
    private String TOPIC_01;

    @Autowired
    private KafkaTemplate<String, MyMessage> messageProducer;

    @Test
    public void testSalesforceMessageListner() {
        MyMessageConsumers myMessageConsumers = new MyMessageConsumers(mockService);
        messageProducer.send(TOPIC_01, "MessageID", new MyMessage());
        verify(myMessageProcessor, times(1)).process(any(MyMessage.class));
    }}

我的测试配置类：

    @Configuration
    @EnableKafka
    public class TestKafkaConfig {
    @Bean
    public MyMessageProcessor myMessageProcessor() {
        return mock(MyMessageProcessor.class);
    }
    @Bean
    public KafkaEmbedded kafkaEmbedded() {
        return new KafkaEmbedded(1, true, 1, "I1.Topic.json.001");
    }

    //Consumer
    @Bean
    public ConsumerFactory<String, MyMessage> myMessageConsumerFactory() {
        Map<String, Object> props = new HashMap<>();
        props.put(ConsumerConfig.BOOTSTRAP_SERVERS_CONFIG, kafkaEmbedded().getBrokersAsString());
        props.put(ConsumerConfig.ENABLE_AUTO_COMMIT_CONFIG, false);
        props.put(ConsumerConfig.AUTO_OFFSET_RESET_CONFIG, "earliest");
        return new DefaultKafkaConsumerFactory<>(props, new StringDeserializer(), new JsonDeserializer<>(MyMessage.class));
    }
    @Bean
    public ConcurrentKafkaListenerContainerFactory<String, MyMessage> myMessageListenerContainerFactory() {
        ConcurrentKafkaListenerContainerFactory<String, MyMessage> factory = new ConcurrentKafkaListenerContainerFactory<>();
        factory.setConsumerFactory(myMessageConsumerFactory());
        return factory;
    }

    //Producer
    @Bean
    public ProducerFactory<String, MyMessage> producerFactory() {
        Map<String, Object> props = new HashMap<>();
        props.put(ProducerConfig.BOOTSTRAP_SERVERS_CONFIG, kafkaEmbedded().getBrokersAsString());
        props.put(ProducerConfig.RETRIES_CONFIG, 0);
        props.put(ProducerConfig.KEY_SERIALIZER_CLASS_CONFIG, StringSerializer.class);
        props.put(ProducerConfig.VALUE_SERIALIZER_CLASS_CONFIG, KafkaMessageSerializer.class);
        return new DefaultKafkaProducerFactory<>(props);
    }
    @Bean
    public KafkaTemplate<String, MyMessage> messageProducer() {
        return new KafkaTemplate<>(producerFactory());
    }
    }

有什么简单的方法可以完成这项工作吗？

或者我应该以其他方式对@KafkaListener 进行测试吗？在单元测试中，如何确保当新消息到达Kafka时调用@KafkaListener。

Answer 1

当新消息到达 Kafka 时，如何确保调用 @KafkaListener。

嗯，这本质上是测试此类功能的框架职责。在您的情况下，您只需要专注于业务逻辑和单元测试您的自定义代码，而不是在框架中编译的代码。此外，测试仅记录传入消息的@KafkaListener 方法也没有什么好处。要找到测试用例验证的钩子肯定太难了。

另一方面，我真的相信您的 @KafkaListener 方法中的业务逻辑比您展示的要复杂得多。因此，验证从该方法调用的自定义代码（例如 DB 插入、其他一些服务调用等）可能会更好，而不是尝试准确找出 myMessageListener() 的钩子。

你用mock(MyMessageProcessor.class) 做的事情确实是业务逻辑验证的好方法。只有代码中的错误在于 EmbeddedKafka 的重复：您使用注释并且还在配置中声明了 @Bean。您应该考虑删除其中一个。尽管尚不清楚您的生产代码在哪里，但它确实不受嵌入式 Kafka 的影响。否则，如果一切都在测试范围内，我看不出您的消费者和生产者工厂配置有任何问题。对于@KafkaListener 和KafkaTemplate，您肯定有一个最小的可能配置。你只需要删除一个@EmbeddedKafka 不要启动代理两次。

Answer 2

您可以将侦听器包装在您的测试用例中。

给定

@SpringBootApplication
public class So52783066Application {

    public static void main(String[] args) {
        SpringApplication.run(So52783066Application.class, args);
    }

    @KafkaListener(id = "so52783066", topics = "so52783066")
    public void listen(String in) {
        System.out.println(in);
    }

}

然后

@RunWith(SpringRunner.class)
@SpringBootTest
public class So52783066ApplicationTests {

    @ClassRule
    public static KafkaEmbedded embeddedKafka = new KafkaEmbedded(1, true, "so52783066");

    @Autowired
    private KafkaListenerEndpointRegistry registry;

    @Autowired
    private KafkaTemplate<String, String> template;

    @Before
    public void setup() {
        System.setProperty("spring.kafka.bootstrap-servers", embeddedKafka.getBrokersAsString());
    }

    @Test
    public void test() throws Exception {
        ConcurrentMessageListenerContainer<?, ?> container = (ConcurrentMessageListenerContainer<?, ?>) registry
                .getListenerContainer("so52783066");
        container.stop();
        @SuppressWarnings("unchecked")
        AcknowledgingConsumerAwareMessageListener<String, String> messageListener = (AcknowledgingConsumerAwareMessageListener<String, String>) container
                .getContainerProperties().getMessageListener();
        CountDownLatch latch = new CountDownLatch(1);
        container.getContainerProperties()
                .setMessageListener(new AcknowledgingConsumerAwareMessageListener<String, String>() {

                    @Override
                    public void onMessage(ConsumerRecord<String, String> data, Acknowledgment acknowledgment,
                            Consumer<?, ?> consumer) {
                        messageListener.onMessage(data, acknowledgment, consumer);
                        latch.countDown();
                    }

                });
        container.start();
        template.send("so52783066", "foo");
        assertThat(latch.await(10, TimeUnit.SECONDS)).isTrue();
    }

}

Answer 3

这是我根据您的代码为消费者提供的工作解决方案。谢谢:-)

配置如下：

@TestConfiguration
@EnableKafka
@Profile("kafka_test")
public class KafkaTestConfig {

    private static Logger log = LoggerFactory.getLogger(KafkaTestConfig.class);

    @Value("${spring.kafka.bootstrap-servers}")
    private String bootstrapServers;

    @Bean
    @Primary
    public Map<String, Object> consumerConfigs() {
        Map<String, Object> props = new HashMap<>();
        props.put(ConsumerConfig.BOOTSTRAP_SERVERS_CONFIG, bootstrapServers);
        props.put(ConsumerConfig.KEY_DESERIALIZER_CLASS_CONFIG, StringDeserializer.class);
        props.put(ConsumerConfig.VALUE_DESERIALIZER_CLASS_CONFIG, JsonDeserializer.class);
        props.put(ConsumerConfig.GROUP_ID_CONFIG, "group-id");
        props.put(ConsumerConfig.ENABLE_AUTO_COMMIT_CONFIG, false);
        props.put(ConsumerConfig.AUTO_OFFSET_RESET_CONFIG, "earliest");
        props.put(ConsumerConfig.SESSION_TIMEOUT_MS_CONFIG, 15000);

        log.info("Consumer TEST config = {}", props);
        return props;
    }

    @Bean
    public Map<String, Object> producerConfigs() {
        Map<String, Object> props = new HashMap<>();
        props.put(ProducerConfig.BOOTSTRAP_SERVERS_CONFIG, bootstrapServers);
        props.put(ProducerConfig.KEY_SERIALIZER_CLASS_CONFIG, StringSerializer.class);
        props.put(ProducerConfig.VALUE_SERIALIZER_CLASS_CONFIG, JsonSerializer.class);

        log.info("Producer TEST config = {}", props);
        return props;
    }

    @Bean
    public ConsumerFactory<String, String> consumerFactory() {
        return new DefaultKafkaConsumerFactory<>(consumerConfigs(), new StringDeserializer(),
                new JsonDeserializer<String>());
    }

    @Bean
    public ProducerFactory<String, String> producerFactory() {
        DefaultKafkaProducerFactory<String, String> pf = new DefaultKafkaProducerFactory<>(producerConfigs());
        return pf;
    }

    @Bean
    public ConcurrentKafkaListenerContainerFactory<String, String> kafkaListenerContainerFactory(
            ConsumerFactory<String, String> kafkaConsumerFactory) {
        ConcurrentKafkaListenerContainerFactory<String, String> factory = new ConcurrentKafkaListenerContainerFactory<>();
        factory.setConsumerFactory(consumerFactory());
        factory.getContainerProperties().setAckOnError(false);
        factory.setConcurrency(2);
        return factory;
    }

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

    @Bean
    public KafkaListenerEndpointRegistry kafkaListenerEndpointRegistry() {
        KafkaListenerEndpointRegistry kafkaListenerEndpointRegistry = new KafkaListenerEndpointRegistry();
        return kafkaListenerEndpointRegistry;
    }
}

将您需要包含在测试中的所有 bean 放在不同的类中：

@TestConfiguration
@Profile("kafka_test")
@EnableKafka
public class KafkaBeansConfig {

    @Bean
    public MyProducer myProducer() {
        return new MyProducer();
    }

    // more beans
}

我创建了一个 BaseKafkaConsumerTest 类来重用它：

@ExtendWith(SpringExtension.class)
@TestPropertySource(properties = { "spring.kafka.bootstrap-servers=${spring.embedded.kafka.brokers}" })
@TestInstance(Lifecycle.PER_CLASS)
@DirtiesContext
@ContextConfiguration(classes = KafkaTestConfig.class)
@ActiveProfiles("kafka_test")
public class BaseKafkaConsumerTest {

    @Autowired
    protected EmbeddedKafkaBroker embeddedKafka;

    @Value("${spring.embedded.kafka.brokers}")
    private String brokerAddresses;

    @Autowired
    protected KafkaListenerEndpointRegistry kafkaListenerEndpointRegistry;

    @Autowired
    protected KafkaTemplate<String, String> senderTemplate;

    public void setUp() {
        embeddedKafka.brokerProperty("controlled.shutdown.enable", true);

        for (MessageListenerContainer messageListenerContainer : kafkaListenerEndpointRegistry
                .getListenerContainers()) {
            System.err.println(messageListenerContainer.getContainerProperties().toString());
            ContainerTestUtils.waitForAssignment(messageListenerContainer, embeddedKafka.getPartitionsPerTopic());
        }
    }

    @AfterAll
    public void tearDown() {
        for (MessageListenerContainer messageListenerContainer : kafkaListenerEndpointRegistry
                .getListenerContainers()) {
            messageListenerContainer.stop();
        }

        embeddedKafka.getKafkaServers().forEach(b -> b.shutdown());
        embeddedKafka.getKafkaServers().forEach(b -> b.awaitShutdown());
    }

}

扩展基类来测试你的消费者：

@EmbeddedKafka(topics = MyConsumer.TOPIC_NAME)
@Import(KafkaBeansConfig.class)
public class MYKafkaConsumerTest extends BaseKafkaConsumerTest {

    private static Logger log = LoggerFactory.getLogger(PaymentMethodsKafkaConsumerTest.class);

    @Autowired
    private MyConsumer myConsumer;

    // mocks with @MockBean

    @Configuration
    @ComponentScan({ "com.myfirm.kafka" })
    static class KafkaLocalTestConfig {
    }

    @BeforeAll
    public void setUp() {
        super.setUp();
    }

    @Test
    public void testMessageIsReceived() throws Exception {

    //mocks

    String jsonPayload = "{\"id\":\"12345\","cookieDomain\":"helloworld"}";
    ListenableFuture<SendResult<String, String>> future =
        senderTemplate.send(MyConsumer.TOPIC_NAME, jsonPayload);

    Thread.sleep(10000);
    future.addCallback(new ListenableFutureCallback<SendResult<String, String>>() {

        @Override
        public void onSuccess(SendResult<String, String> result) {
            log.info("successfully sent message='{}' with offset={}", jsonPayload,
                result.getRecordMetadata().offset());
        }

        @Override
        public void onFailure(Throwable ex) {
            log.error("unable to send message='{}'", jsonPayload, ex);
        }
    });

    Mockito.verify(myService, Mockito.times(1))
    .update(Mockito.any(MyDetails.class));
}

正如我在其他帖子中所读到的，不要以这种方式测试业务逻辑。只是打了电话。