Android Mockito-Kotlin错误-“实际上，与该模拟程序的交互为零”

Question

以下是我的ViewModel类的测试代码。我的应用程序架构基于MVI。基本上，我正在尝试模拟我的repo和state类。在下面编写的测试函数中，当我从API成功加载新闻列表时，我试图检查状态是否以正确的顺序更改。

class NewsListViewModelTest {
    //...

    @get:Rule
    val testSchedulerRule = RxTestSchedulerRule()

    private lateinit var testSubject: NewsListViewModel    

    private val loadingState = NewsListState(state = State.LOADING)

    private val newsRepo = mock<NewsRepository>()
    private val observer = mock<Observer<NewsListState>>()

    @Before
    fun setUp() {
        testSubject = NewsListViewModel(newsRepo)
        testSubject.observableState.observeForever(observer)
    }

    @Test
    fun `Given news list successfully loaded, when action LoadNewsList is received, then state contains news list`() {
        // GIVEN
        val newsList = listOf(News("title", "description", Date(), "image"))
        val successState = NewsListState(newsList = newsList, state = State.DATA)

        whenever(newsRepo.loadAll("keyword", 1, 1))
            .thenReturn(Observable.just(newsList))

        // WHEN
        testSubject.dispatch(NewsListAction.LoadNewsList("keyword"))
        testSchedulerRule.triggerActions()

        // THEN
        inOrder(observer) {
            verify(observer).onChanged(loadingState)
            verify(observer).onChanged(successState)
        }
        verifyNoMoreInteractions(observer)
    }
}

但是，当我运行此测试时，在inOrder(observer){ ... }的第一行出现了以下错误：

Wanted but not invoked:
observer.onChanged(
    NewsListState(newsList=[], state=LOADING, errorMessage=)
);
-> at [packagename].NewsListViewModelTest.Given news list failed to load, when action LoadNewsList is received, then state contains error(NewsListViewModelTest.kt:77)
Actually, there were zero interactions with this mock.

这些是我的测试依赖项：

testImplementation 'junit:junit:4.12'
testImplementation 'androidx.arch.core:core-testing:2.1.0'
testImplementation 'com.nhaarman.mockitokotlin2:mockito-kotlin:2.2.0'

此错误的原因可能是什么？

Edit-我的RxTestSchedulerRule类：

class RxTestSchedulerRule(private val testScheduler: TestScheduler = TestScheduler()) : Scheduler(),
    TestRule {
    override fun apply(base: Statement, description: Description?): Statement {
        RxJavaPlugins.setIoSchedulerHandler { testScheduler }
        RxJavaPlugins.setComputationSchedulerHandler { testScheduler }
        RxJavaPlugins.setNewThreadSchedulerHandler { testScheduler }
        RxJavaPlugins.setSingleSchedulerHandler { testScheduler }
        RxAndroidPlugins.setInitMainThreadSchedulerHandler { Schedulers.trampoline() }
        return base
    }

    override fun createWorker() = testScheduler.createWorker()

    fun triggerActions() = testScheduler.triggerActions()
}

Edit 2-我的调度功能：

fun dispatch(?) {
     newsRepository.loadAll(keyword = it.keyword, 
                            pageSize = pageSize, 
                            page = page)
                   .subscribeOn(Schedulers.io()) 
                   .map<NewsListChange> { newsList -> 
                         NewsListChange.Data(newsList) } 
                  .defaultIfEmpty(NewsListChange.Data(emptyList())) 
                  .onErrorReturn { throwable -> 
                       NewsListChange.Error(throwable) } 
                  .startWith(NewsListChange.Loading)
}

Answer 1

请尝试代替此行

whenever(newsRepo.loadAll("keyword", 1, 1))
            .thenReturn(Observable.just(newsList))

放置

whenever(newsRepo.loadAll(anyString(), anyInt(), anyInt()))
            .thenReturn(Observable.just(newsList))