单元测试ListenableFuture kafkaTemplate.send始终返回null [英] unit testing ListenableFuture kafkaTemplate.send always returns null

问题描述

我正在尝试对来自kafkaTemplate.send()的回调进行单元测试，但其无法正常工作.这是我要测试的代码片段.

I'm trying to unit test the callbacks from the kafkaTemplate.send() but its not working as expected. here's the code snippet of the code im trying to test.

    @Override
    public void sendMessage(String topicName, String message) {

        ListenableFuture<SendResult<String, String>> future = kafkaTemplate.send(topicName, message);
        future.addCallback(new ListenableFutureCallback<SendResult<String, String>>() {

            @Override
            public void onSuccess(SendResult<String, String> result) {
                System.out.print("Success")
            }
            @Override
            public void onFailure(Throwable ex) {
                System.out.print("Failed")
            }
        });
    }

这是单元测试代码

    private KafkaTemplate<String, String> kafkaTemplate;
    private KafkaService kafkaService;
    private SendResult<String, String> sendResult;
    private ListenableFuture<SendResult<String, String>> future;
    private RecordMetadata recordMetadata
    private String topicName
    private String message



    def setup() {
        kafkaTemplate = Mock(KafkaTemplate.class)
        kafkaService = new KafkaService(kafkaTemplate);
        topicName = "test.topic"
        message = "test message"
        sendResult = Mock(SendResult.class);
        future = Mock(ListenableFuture.class);
        recordMetadata = new RecordMetadata(new TopicPartition(topicName, 1), 1L, 0L, 0L, 0L, 0, 0);
    }

    def "Test success send message method"() {
        given:
        sendResult.getRecordMetadata() >> recordMetadata
        kafkaTemplate.send(_ as String, _ as String) >> future

        when:
        kafkaService.sendMessage(topicName, message)

        then:
        // catch success or failed here.

        1 * kafkaTemplate.send(_,_) >> {arguments ->
            final String topicNameParam = arguments.get(0)
            final String messageParam = arguments.get(1)

            assert topicNameParam == topicName
            assert messageParam == message
        }
    }

基于调试器的将来，在这种情况下为空

based on the debugger future is null on this scenario

ListenableFuture<SendResult<String, String>> future = kafkaTemplate.send(topicName, message); // future null
 future.addCallback(new ListenableFutureCallback<SendResult<String, String>>() { // future null

我在这里已经阅读了很多答案，但是并不能解决问题，或者他们还没有很好地解释我会明白问题出在哪里.像这样的 https://stackoverflow.com/a/56677098

i already read a lot of answers here but it does not solved the issue or havent they explain it well that i would understand where the problem is. like this one https://stackoverflow.com/a/56677098

感谢您的提前帮助！

推荐答案

在尝试

You are making a typical Spock beginner's mistake when trying to combine mocking and stubbing: First declare a stub result in the given: block and later a checked mock interaction (without stub result) in the then: block. But mocking and stubbing always have to happen in the same interaction as described in the manual chapter I linked to. The manual also explains that the interaction in the then: block wins in your case, i.e. because you do not specify a stub result there, the result will default to null.

此外，您使论证验证变得比必需的困难得多.只需使用简单的参数约束即可.如果您这样更改测试，则该测试将通过:

Furthermore, you make the argument verification much more difficult than necessary. Just use simple argument constraints instead. Your test will pass if you change it like this:

  def "Test success send message method"() {
    given:
    sendResult.getRecordMetadata() >> recordMetadata
//    kafkaTemplate.send(_ as String, _ as String) >> future

    when:
    kafkaService.sendMessage(topicName, message)

    then:
    // catch success or failed here.
    1 * kafkaTemplate.send(topicName, message) >> future
  }

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