如何在 Spring 测试中监视自动装配的 bean

Question

I have a simple logging handler beans configuration which I inject into an IntegrationFlow

@Configuration
class LogHandlerConfiguration {

    private LoggingHandler handler;

    @Bean
    public MessageHandler kafkaSuccessHandler() {
        return getLogger(LoggingHandler.Level.INFO);
    }

    @Bean(name="kafkaFailureHandler")
    public MessageHandler kafkaFailureHandler() {
        return getLogger(LoggingHandler.Level.ERROR);
    }

    private LoggingHandler getLogger(LoggingHandler.Level level) {
        handler = new LoggingHandler(level);
        handler.setShouldLogFullMessage(Boolean.TRUE);
        return handler;
    }
}

the integration flow to test

@Bean
IntegrationFlow kafkaFailureFlow(ExecutorChannel kafkaErrorChannel, MessageHandler kafkaFailureHandler) {
    return IntegrationFlows.from(kafkaErrorChannel)
            .transform("payload.failedMessage")
            .handle(kafkaFailureHandler)
            .get();
}

Here's my test

@SpyBean
MessageHandler kafkaFailureHandler;

@BeforeEach
public void setup() {
    MockitoAnnotations.openMocks(KafkaPublishFailureTest.class);
}

@Test
void testFailedKafkaPublish() {

    //Dummy message
    Map<String, String> map = new HashMap<>();
    map.put("key", "value");
    // Publish Message
    Message<Map<String, String>> message = MessageBuilder.withPayload(map)
            .setHeader("X-UPSTREAM-TYPE", "alm")
            .setHeader("X-UPSTREAM-INSTANCE", "jira")
            .setHeader("X-MESSAGE-KEY", "key-1")
            .build();

    kafkaGateway.publish(message);
    // Failure handler called
    Mockito.verify(kafkaFailureHandler, Mockito.timeout(0).atLeastOnce()).handleMessage(
            ArgumentMatchers.any(Message.class));
}

We've created a generic Kafka Producer, Consumer configuration to which downsteam apps can attach failure and success handler best suited to their needs. I'm not able to verify the the LoggingHandler in this case is called atleast once.

The failureHandler gets executed under an ExecturoeChannel backed by ThreadPoolTaskExecutor

@Bean
ExecutorChannel kafkaErrorChannel(Executor threadPoolExecutor) {
    return MessageChannels.executor("kafkaErrorChannel", threadPoolExecutor).get();
}

failures are handled via retry advice

@Bean
RequestHandlerRetryAdvice retryAdvice(ExecutorChannel kafkaErrorChannel) {
    RequestHandlerRetryAdvice retryAdvice = new RequestHandlerRetryAdvice();
    retryAdvice.setRecoveryCallback(new ErrorMessageSendingRecoverer(kafkaErrorChannel));
    return retryAdvice;
}

I get this error when I run the test

java.lang.IllegalStateException: No bean found for definition [SpyDefinition@44dfdd58 name = '', typeToSpy = org.springframework.messaging.MessageHandler, reset = AFTER]
    at org.springframework.util.Assert.state(Assert.java:97) ~[spring-core-5.3.4.jar:5.3.4]
    at org.springframework.boot.test.mock.mockito.MockitoPostProcessor.inject(MockitoPostProcessor.java:351) ~[spring-boot-test-2.4.3.jar:2.4.3]

Answer 1

Here is what I've tried and ti works:

@SpringBootApplication
public class Demo1Application {

    public static void main(String[] args) {
        SpringApplication.run(Demo1Application.class, args);
    }

    @Bean
    ExecutorChannel kafkaErrorChannel(TaskExecutor taskExecutor) {
        return new ExecutorChannel(taskExecutor);
    }

    @Bean
    public MessageHandler kafkaFailureHandler() {
        LoggingHandler handler = new LoggingHandler(LoggingHandler.Level.ERROR);
        handler.setShouldLogFullMessage(Boolean.TRUE);
        return handler;
    }

    @Bean
    IntegrationFlow kafkaFailureFlow(ExecutorChannel kafkaErrorChannel, MessageHandler kafkaFailureHandler) {
        return IntegrationFlows.from(kafkaErrorChannel)
                .transform("payload.failedMessage")
                .handle(kafkaFailureHandler)
                .get();
    }

}

---

@SpringBootTest
class Demo1ApplicationTests {

    @Autowired
    ExecutorChannel kafkaErrorChannel;

    @SpyBean
    MessageHandler kafkaFailureHandler;

    @Test
    void testSpyBean() throws InterruptedException {
        MessagingException payload = new MessageHandlingException(new GenericMessage<>("test"));
        this.kafkaErrorChannel.send(new ErrorMessage(payload));
        Thread.sleep(1000);
        Mockito.verify(this.kafkaFailureHandler).handleMessage(ArgumentMatchers.any(Message.class));
    }

}

Perhaps your problem that you don't include LogHandlerConfiguration into your @SpringBootTest configuration. That's why I asked a simple project to play with. Your code with all those properties are too custom to just copy/paste into my environment...

Also pay attention to that Thread.sleep(1000); . Since your kafkaErrorChannel is an ExecutorChannel , the message consumption happens on a different thread leaving your main testing thread and leading to a failure because of race condition. It is hard to guess the proper timing, so better to stub a mock method to fulfill some thread barrier like new CountDownLatch(1) and wait for it in the test.

Out of subject you can also investigate Spring Integration Testing Framework: https://docs.spring.io/spring-integration/docs/current/reference/html/testing.html#test-context

Answer 2

So, was hung up over Why not @SpyBean ? There were two problems

1. both success and failure handlers were MessageHandlers confusing @SpyBean
2. The Kafka producer waiting time was too high, ie 1000ms

Here's what Finally worked, using a named bean

@Bean("kafkaFailureHandler")
public MessageHandler kafkaFailureHandler() {
    LoggingHandler handler = new LoggingHandler(LoggingHandler.Level.INFO);
    handler.setShouldLogFullMessage(Boolean.TRUE);
    return handler;
}

and then in tests reducing the max block too

@DirtiesContext
@SpringBootTest(classes = {KafkaHandlerConfiguration.class, SwiftalkKafkaGateway.class})
@SpringIntegrationTest(noAutoStartup = {"kafkaFailureFlow"})
@TestPropertySource(properties = {
        "spring.main.banner-mode=off",
        "logging.level.root=INFO",
        "logging.level.org.springframework=INFO",
        "logging.level.org.springframework.integration=DEBUG",
        "spring.kafka.producer.properties.max.block.ms=50",
        "spring.kafka.producer.bootstrap-servers=localhost:9999",
        "spring.kafka.producer.key-serializer=org.apache.kafka.common.serialization.StringSerializer",
        "spring.kafka.producer.value-serializer=org.springframework.kafka.support.serializer.JsonSerializer",
})
public class KafkaPublishFailureTest {

    private static final Logger log = LogManager.getLogger(KafkaPublishFailureTest.class);

    @Autowired
    SwiftalkKafkaGateway kafkaGateway;

    @SpyBean(name = "kafkaFailureHandler")
    MessageHandler kafkaFailureHandler;

    @Test
    @SuppressWarnings("all")
    void testFailedKafkaPublish() throws InterruptedException {

        //Dummy message
        Map<String, String> map = new HashMap<>();
        map.put("key", "value");
        // Publish Message
        Message<Map<String, String>> message = MessageBuilder.withPayload(map)
                .setHeader("X-UPSTREAM-TYPE", "alm")
                .setHeader("X-UPSTREAM-INSTANCE", "jira")
                .setHeader("X-MESSAGE-KEY", "key-1")
                .build();

        kafkaGateway.publish(message);
        verify(this.kafkaFailureHandler, timeout(500)).handleMessage(any(Message.class));
    }

}

notice the spring.kafka.producer.properties.max.block.ms=50 and verify(this.kafkaFailureHandler, timeout(500)).handleMessage(any(Message.class));