如何在 Mono.flatMap() 中模擬方法？

Question

我為某些服務編寫單元測試，但我不明白，為什么我模擬的某些方法不調用。 我嘗試測試testDeleteDeviceWhenDeviceNotFound()方法並且它通過了，但是當我嘗試testDeleteDeviceSuccess()我有問題

@Service
@Slf4j
@AllArgsConstructor
public class DeviceService {

    private DeviceRepository deviceRepository;
    private SyncSender syncSender;

    public Mono<Void> deleteDevice(long deviceId) {
        return deviceRepository
                .findById(deviceId)
                .switchIfEmpty(Mono.error(new NotFoundException()))
                .flatMap(existingDevice -> deviceRepository
                        .delete(existingDevice)
                        .then(syncSender.sendDeviceDelete(existingDevice.getDeviceId()))
                );
    }

和 myTest

   @ExtendWith(MockitoExtension.class)
class DeviceServiceTest {
    @Mock
    private DeviceRepository deviceRepository;
    @Mock
    private SyncSender syncSender;
    @InjectMocks
    private DeviceService deviceService;

    @Test
@DisplayName("Test deleteDevice when NotFoundException")
void testDeleteDeviceWhenDeviceNotFound() {
    long deviceId = 100L;
    Mockito.when(deviceRepository.findById(deviceId)).thenReturn(Mono.empty());
    Mono<Void> mono = deviceService.deleteDevice(deviceId);
    StepVerifier
            .create(mono)
            .expectErrorMatches(throwable -> throwable instanceof NotFoundException)
            .verify();
}
    @Test
    @DisplayName("Test deleteDevice success")
    void testDeleteDeviceSuccess() {
        DeviceModel deviceModel = createDeviceModel();
        deviceModel.setDeviceId(100L);
        Mockito.when(deviceRepository.findById(deviceModel.getDeviceId())).thenReturn(Mono.just(deviceModel));
        Mockito.when(syncSender.sendDeviceDelete(anyLong())).thenReturn(Mono.empty());
        Mockito.when(deviceRepository.delete(any(DeviceModel.class))).thenReturn(Mono.empty());
        deviceService.deleteDevice(deviceModel.getDeviceId());

    }
}

來自 junit 的異常，即在測試執行期間，在被測代碼中從未實現存根方法之一

    org.mockito.exceptions.misusing.UnnecessaryStubbingException: 
Unnecessary stubbings detected.
Clean & maintainable test code requires zero unnecessary code.
Following stubbings are unnecessary (click to navigate to relevant line of code):
  1. -> at com.ecosoft.dms.device.vending.service.DeviceServiceTest.testDeleteDeviceSuccess(DeviceServiceTest.java:172)
  2. -> at com.ecosoft.dms.device.vending.service.DeviceServiceTest.testDeleteDeviceSuccess(DeviceServiceTest.java:173)
Please remove unnecessary stubbings or use 'lenient' strictness. More info: javadoc for UnnecessaryStubbingException class.

當我嘗試調試模式時，我看到我回到了這一步。為什么？

.flatMap(existingDevice -> deviceRepository

Answer 1

在你失敗的測試中，你有：

deviceService.deleteDevice(deviceModel.getDeviceId());

這將創建一個 mono，但從不啟動底層異步任務。 測試完成，並且 Mockito 正確報告從未調用存根方法。

您在其他測試中使用了 StepVerifier，在我看來，您還需要在這里使用它來觸發底層異步操作

StepVerifier.create(deviceService.deleteDevice(deviceModel.getDeviceId()))
            .verifyComplete();

檢查更簡單的示例：

@Test
void testMonoNotRun() {
    Mono.fromCallable(() -> {
        System.out.println("Callable run");
        return 1;
    });
}

@Test
void testMonoRunBySubscribe() {
    Mono.fromCallable(() -> {
        System.out.println("Callable run");
        return 1;
    }).subscribe();
}

@Test
void testMonoRunByStepVerify() {
    StepVerifier.create(Mono.fromCallable(() -> {
        System.out.println("Callable run");
        return 1;
    })).verifyComplete();
}