Question

我有以下包含成员变量的类，但是Mockito似乎无法模拟成员变量的方法。下面是我的被测系统：

public class MessageConsumer {

    private ConsumerResponse consumerResponse;
    private NotificationConsumer notificationConsumer;

    @Scheduled(cron = "${com.example.value}")
    public void fetch() {
        consumerResponse = notificationConsumer.fetchWithReturnConsumerResponse(); //no exception thrown on this line at all -- but could this be the cause of the problem in the test?
        System.out.println("consumerResponse's responseCode: " + consumerResponse.getResponseCode()); // NullPointerException thrown here
    }

    public ConsumerResponse setConsumerResponse(ConsumerResponse consumerResponse) {
        this.consumerResponse = consumerResponse;
    }

    public ConsumerResponse getConsumerResponse() {
        return consumerResponse;
    }
}

以下是该类的相关JUnit测试：

@SpringBootTest
@RunWith(MockitoJUnitRunner.class)
public class MessageConsumerTest {

    @Mock
    private ConsumerResponse consumerResponse;

    @InjectMocks
    private MessageConsumer messageConsumer;

    @Before
    public void setup() {
        MockitoAnnotations.initMocks(this);
    }

    //Failing unit test
    @Test
    public void getResponseCodeShouldReturn200() {
        Mockito.when(consumerResponse.getResponseCode()).thenReturn("200");
        messageConsumer.fetch()
    }

}

如您所见，我模拟了ConsumerResponse consumerResponse变量，以在调用"200"方法时返回consumerResponse.getResponseCode()。相反，我得到一个NullPointerException。

我敢肯定，我正确地嘲笑了成员变量并适当地对其进行了初始化（initMocks）。我花了几天的时间试图解决这个问题。我要去哪里错了？

Answer 1

由于NotificationConsumer也是此类的外部依赖项，因此您还必须模拟该类，否则consumerResponse = notificationConsumer.fetchWithReturnConsumerResponse();将在测试中进入null，因为您没有模拟NotificationConsumer。另外，我建议不要在此单元测试中使用@SpringBootTest，因为此注释将引导整个Spring上下文。以下代码片段应为您提供帮助：

@RunWith(MockitoJUnitRunner.class)
public class MessageConsumerTest {

    @Mock
    private ConsumerResponse consumerResponse;

    @Mock
    private NotificationConsumer notificationConsumer;

    @InjectMocks
    private MessageConsumer messageConsumer;

    @Before
    public void setup() {
        MockitoAnnotations.initMocks(this);
    }

    @Test
    public void getResponseCodeShouldReturn200() {
        Mockito.when(notificationConsumer.fetchWithReturnConsumerResponse()).thenReturn(consumerResponse);
        Mockito.when(consumerResponse.getResponseCode()).thenReturn("200");
        messageConsumer.fetch();
    }

}

Mockito没有模拟出成员变量方法的返回值

1 个答案: