问使用RxJava2和MutableLiveData进行单元测试

EN

val temperature = MutableLiveData<Double>()

fun save(): Single<Result<ClassifyResponse>> {
    val temp = temperature.value
    ...
    return repository.classify(request)
        .flatMap { response->
                val result: Result<ClassifyResponse> = Result.Success(response)
                Single.just(result)
        }.onErrorReturn {
                Result.Error(it)
        }
}

java.lang.RuntimeException: Method getMainLooper in android.os.Looper not mocked. See http://g.co/androidstudio/not-mocked for details.

class MyViewModelTest() {

    private val repository = mock(MyRepository::class.java)

    private val immediateScheduler = object : Scheduler() {
        override fun createWorker(): Worker {
            return ExecutorScheduler.ExecutorWorker(Executor { it.run() })
        }
    }

    @Before
    fun setUp() {
        RxJavaPlugins.setInitIoSchedulerHandler { immediateScheduler }
        RxJavaPlugins.setComputationSchedulerHandler { immediateScheduler }
        RxAndroidPlugins.setInitMainThreadSchedulerHandler { immediateScheduler }
        RxAndroidPlugins.setInitMainThreadSchedulerHandler { immediateScheduler }
    }

    @Test
    fun test() {
        // given temperature view model
        val viewModel = MyViewModel(repository)
        ...

        val classifyResponse = ClassifyResponse(...)
        `when`(repository.classify(any(ClassifyRequest::class.java))).then { Single.just(classifyResponse) }

        // when sending request
        val result = viewModel.save()

        // then verify result
        val expected = Result.success(classifyResponse)

        assertEquals(expected, result)
    }
}