Android 使用LiveData的JUnit5测试不';t执行订户';s回调
背景: 我有一个简单的应用程序,它使用RESTAPI调用获取电影列表。项目结构如下所示:Android 使用LiveData的JUnit5测试不';t执行订户';s回调,android,junit,mockito,android-livedata,android-viewmodel,Android,Junit,Mockito,Android Livedata,Android Viewmodel,背景: 我有一个简单的应用程序,它使用RESTAPI调用获取电影列表。项目结构如下所示: Activity -> ViewModel -> Repository -> ApiService (Retrofit Interface) 活动订阅LiveData并侦听事件更改 ViewModel承载活动观察到的MediatorLiveData。最初,ViewModel在MediatorLiveData中设置一个资源。加载(..)值 ViewModel然后调用存储库从ApiSer
Activity -> ViewModel -> Repository -> ApiService (Retrofit Interface)
资源。加载(..)
值
Resource.success(…)
或Resource.error(…)
资源。加载(..)
是由MediatorLiveData从ViewModel进行的。MediatorLiveData从不从存储库发出任何数据
ViewModel.class
private var discoverMovieLiveData: MediatorLiveData<Resource<DiscoverMovieResponse>> = MediatorLiveData()
fun observeDiscoverMovie(): LiveData<Resource<DiscoverMovieResponse>> {
return discoverMovieLiveData
}
fun fetchDiscoverMovies(page: Int) {
discoverMovieLiveData.value = Resource.loading(null) // this emit get observed immediately
val source = movieRepository.fetchDiscoverMovies(page)
discoverMovieLiveData.addSource(source) {
discoverMovieLiveData.value = it // never gets called
discoverMovieLiveData.removeSource(source)
}
}
fun fetchDiscoverMovies(page: Int): LiveData<Resource<DiscoverMovieResponse>> {
return LiveDataReactiveStreams.fromPublisher(
apiService.fetchDiscoverMovies(page)
.subscribeOn(Schedulers.io())
.map { d ->
Resource.success(d) // never gets called in unit test
}
.onErrorReturn { e ->
Resource.error(ApiErrorHandler.getErrorByThrowable(e), null) // // never gets called in unit test
}
)
}
class RxImmediateSchedulerRule : TestRule {
private val immediate = object : Scheduler() {
override fun createWorker(): Worker {
return ExecutorScheduler.ExecutorWorker(Executor { it.run() })
}
}
override fun apply(base: Statement, description: Description): Statement {
return object : Statement() {
@Throws(Throwable::class)
override fun evaluate() {
RxJavaPlugins.setInitIoSchedulerHandler { immediate }
RxJavaPlugins.setInitComputationSchedulerHandler { immediate }
RxJavaPlugins.setInitNewThreadSchedulerHandler { immediate }
RxJavaPlugins.setInitSingleSchedulerHandler { immediate }
RxAndroidPlugins.setInitMainThreadSchedulerHandler { immediate }
try {
base.evaluate()
} finally {
RxJavaPlugins.reset()
RxAndroidPlugins.reset()
}
}
}
}
}
class InstantExecutorExtension : BeforeEachCallback, AfterEachCallback {
override fun beforeEach(context: ExtensionContext?) {
ArchTaskExecutor.getInstance().setDelegate(object : TaskExecutor() {
override fun executeOnDiskIO(runnable: Runnable) {
runnable.run()
}
override fun postToMainThread(runnable: Runnable) {
runnable.run()
}
override fun isMainThread(): Boolean {
return true
}
})
}
override fun afterEach(context: ExtensionContext?) {
ArchTaskExecutor.getInstance().setDelegate(null)
}
}
}
RxImmediateSchedulerRule.class
private var discoverMovieLiveData: MediatorLiveData<Resource<DiscoverMovieResponse>> = MediatorLiveData()
fun observeDiscoverMovie(): LiveData<Resource<DiscoverMovieResponse>> {
return discoverMovieLiveData
}
fun fetchDiscoverMovies(page: Int) {
discoverMovieLiveData.value = Resource.loading(null) // this emit get observed immediately
val source = movieRepository.fetchDiscoverMovies(page)
discoverMovieLiveData.addSource(source) {
discoverMovieLiveData.value = it // never gets called
discoverMovieLiveData.removeSource(source)
}
}
fun fetchDiscoverMovies(page: Int): LiveData<Resource<DiscoverMovieResponse>> {
return LiveDataReactiveStreams.fromPublisher(
apiService.fetchDiscoverMovies(page)
.subscribeOn(Schedulers.io())
.map { d ->
Resource.success(d) // never gets called in unit test
}
.onErrorReturn { e ->
Resource.error(ApiErrorHandler.getErrorByThrowable(e), null) // // never gets called in unit test
}
)
}
class RxImmediateSchedulerRule : TestRule {
private val immediate = object : Scheduler() {
override fun createWorker(): Worker {
return ExecutorScheduler.ExecutorWorker(Executor { it.run() })
}
}
override fun apply(base: Statement, description: Description): Statement {
return object : Statement() {
@Throws(Throwable::class)
override fun evaluate() {
RxJavaPlugins.setInitIoSchedulerHandler { immediate }
RxJavaPlugins.setInitComputationSchedulerHandler { immediate }
RxJavaPlugins.setInitNewThreadSchedulerHandler { immediate }
RxJavaPlugins.setInitSingleSchedulerHandler { immediate }
RxAndroidPlugins.setInitMainThreadSchedulerHandler { immediate }
try {
base.evaluate()
} finally {
RxJavaPlugins.reset()
RxAndroidPlugins.reset()
}
}
}
}
}
class InstantExecutorExtension : BeforeEachCallback, AfterEachCallback {
override fun beforeEach(context: ExtensionContext?) {
ArchTaskExecutor.getInstance().setDelegate(object : TaskExecutor() {
override fun executeOnDiskIO(runnable: Runnable) {
runnable.run()
}
override fun postToMainThread(runnable: Runnable) {
runnable.run()
}
override fun isMainThread(): Boolean {
return true
}
})
}
override fun afterEach(context: ExtensionContext?) {
ArchTaskExecutor.getInstance().setDelegate(null)
}
}
InstantExecutorExtension.class
private var discoverMovieLiveData: MediatorLiveData<Resource<DiscoverMovieResponse>> = MediatorLiveData()
fun observeDiscoverMovie(): LiveData<Resource<DiscoverMovieResponse>> {
return discoverMovieLiveData
}
fun fetchDiscoverMovies(page: Int) {
discoverMovieLiveData.value = Resource.loading(null) // this emit get observed immediately
val source = movieRepository.fetchDiscoverMovies(page)
discoverMovieLiveData.addSource(source) {
discoverMovieLiveData.value = it // never gets called
discoverMovieLiveData.removeSource(source)
}
}
fun fetchDiscoverMovies(page: Int): LiveData<Resource<DiscoverMovieResponse>> {
return LiveDataReactiveStreams.fromPublisher(
apiService.fetchDiscoverMovies(page)
.subscribeOn(Schedulers.io())
.map { d ->
Resource.success(d) // never gets called in unit test
}
.onErrorReturn { e ->
Resource.error(ApiErrorHandler.getErrorByThrowable(e), null) // // never gets called in unit test
}
)
}
class RxImmediateSchedulerRule : TestRule {
private val immediate = object : Scheduler() {
override fun createWorker(): Worker {
return ExecutorScheduler.ExecutorWorker(Executor { it.run() })
}
}
override fun apply(base: Statement, description: Description): Statement {
return object : Statement() {
@Throws(Throwable::class)
override fun evaluate() {
RxJavaPlugins.setInitIoSchedulerHandler { immediate }
RxJavaPlugins.setInitComputationSchedulerHandler { immediate }
RxJavaPlugins.setInitNewThreadSchedulerHandler { immediate }
RxJavaPlugins.setInitSingleSchedulerHandler { immediate }
RxAndroidPlugins.setInitMainThreadSchedulerHandler { immediate }
try {
base.evaluate()
} finally {
RxJavaPlugins.reset()
RxAndroidPlugins.reset()
}
}
}
}
}
class InstantExecutorExtension : BeforeEachCallback, AfterEachCallback {
override fun beforeEach(context: ExtensionContext?) {
ArchTaskExecutor.getInstance().setDelegate(object : TaskExecutor() {
override fun executeOnDiskIO(runnable: Runnable) {
runnable.run()
}
override fun postToMainThread(runnable: Runnable) {
runnable.run()
}
override fun isMainThread(): Boolean {
return true
}
})
}
override fun afterEach(context: ExtensionContext?) {
ArchTaskExecutor.getInstance().setDelegate(null)
}
}
指定
RxImmediateSchedulerRule
的方式对JUnit5不起作用。如果在apply()
方法中放置断点,您将看到它没有被执行
相反,您应该创建指定的扩展:
然后在测试类的注释中应用TestSchedulerExtension
:
@ExtendWith(value = [InstantExecutorExtension::class, TestSchedulerExtension::class])
class MainViewModelTest {
private val apiService: ApiService = mock()
private lateinit var movieRepository: MovieRepository
private lateinit var viewModel: MainViewModel
@BeforeEach
fun init() {
movieRepository = MovieRepository(apiService)
viewModel = MainViewModel(movieRepository)
}
@Test
fun loadMovieListFromNetwork() {
val mockResponse = DiscoverMovieResponse(1, emptyList(), 100, 10, 0, "", false)
val call: Flowable = Flowable.just(mockResponse)
whenever(apiService.fetchDiscoverMovies(1)).thenReturn(call)
viewModel.fetchDiscoverMovies(1)
assertEquals(Resource.success(mockResponse), LiveDataTestUtil.getValue(viewModel.discoverMovieLiveData))
}
}
现在测试将通过。现在您已经进行了测试,该观察器已按预期值调度
从另一个角度:这是单元测试吗?当然不是,因为在这个测试中,我们与两个单元交互:
MainViewModel
和MovieRepository
。这更符合“集成测试”的术语。如果您模拟了MoviesRepository
,那么这将是一个有效的单元测试:
@ExtendWith(value = [InstantExecutorExtension::class, TestSchedulerExtension::class])
class MainViewModelTest {
private val movieRepository: MovieRepository = mock()
private val viewModel = MainViewModel(movieRepository)
@Test
fun loadMovieListFromNetwork() {
val mockResponse = DiscoverMovieResponse(1, emptyList(), 100, 10, 0, "", false)
val liveData =
MutableLiveData>().apply { value = Resource.success(mockResponse) }
whenever(movieRepository.fetchDiscoverMovies(1)).thenReturn(liveData)
viewModel.fetchDiscoverMovies(1)
assertEquals(Resource.success(mockResponse), getValue(viewModel.discoverMovieLiveData))
}
}
注意,
MovieRepository
应与fetchDiscoverMovies()
一起声明为open
,以便能够模拟它。另外,你可以考虑使用插件。 我认为你所需要做的只是改变< /P>
val call: Flowable<DiscoverMovieResponse> = successCall(mockResponse)
val调用:Flowable=successCall(mockResponse)
到
val调用:Flowable=Flowable.just(mockResponse)
和使用来自架构组件google示例的类。因此,您需要将其复制/粘贴到您的项目中
因此,在一天结束时,您的新测试将如下所示(假设所有关联和模拟都正确地设置在测试类的顶部)。此外,您正在使用一个InstantExecutoExtension,就像上面azizbekian向您展示的那样
@Test
fun loadMovieListFromNetwork() {
val mockResponse = DiscoverMovieResponse(1, emptyList(), 100, 10)
val call: Flowable<DiscoverMovieResponse> = Flowable.just(mockResponse)
whenever(apiService.fetchDiscoverMovies(1)).thenReturn(call)
viewModel.fetchDiscoverMovies(1)
assertEquals(Resource.success(mockResponse), LiveDataTestUtil.getValue(viewModel.discoverMovieLiveData))
}
@测试
乐趣加载MovieListFromNetwork(){
val mockResponse=DiscoverMovieResponse(1,emptyList(),100,10)
val调用:Flowable=Flowable.just(mockResponse)
无论何时(apiService.fetchDiscoverMovies(1))。然后返回(调用)
viewModel.FetchDiscoveryMovies(1)
assertEquals(Resource.success(mockResponse)、LiveDataTestUtil.getValue(viewModel.discoverMovieLiveData))
}
如果该测试通过,则意味着您能够成功观察网络请求的结果并返回成功的响应。您可以添加
liveData.observeForever
的代码吗?与其使用ArgumentMatcher,不如使用ArgumentCaptor并比较Resource.loading返回的实际内容。在存储库中,io调度程序上订阅了apiService.FetchDiscoveryMovies(),这意味着Flowable不会在同一线程上同步发送通知。因此,请检查您是否正确配置了测试调度程序。@SanlokLee观察得很好。我更改了线程,但无法使LiveData与Rx一起工作。请检查我更新的问题。@second ObserveForver是androidx.Lifecycle中的内置方法。您能在github发布一个带有该设置的最小项目吗?我去看看。非常感谢。在这一点上,我很想知道1。在单元测试中,若我们模拟“movieRepository”,那个么将不会和apiService交互。可以吗?2.编写单元测试和交互测试的最佳实践是什么?我应该为每一个写两个测试函数吗?或者我应该将它们放在不同的目录中吗?1。单元测试是指单元测试。在您的例子中,您希望在ViewModel
类中测试的单元,这意味着任何其他依赖项都应该被存根。在您的例子中,ViewModel
甚至不知道ApiService
类的存在,因此不与ApiService
交互是完全可以的。与ApiService
交互是错误的(如果您使用单元测试介绍ViewModel
)。我不知道你所说的“互动”是什么意思。也许你的意思是“整合”。集成测试将意味着同时测试多个组件。例如,执行操作foo
会在SharedPrefs
中保存一个值,然后验证SharedPrefs
实际上保留了该值。在您的例子中,有一个API层,这意味着您可以查看库。现在一切都清楚了。我应该把单元测试和集成类放在/test文件夹中吗?有什么惯例吗?这个答案太棒了,但是,我试过了,但它对我不起作用。我在beforeTestExecution(context:ExtensionContext?)方法中添加了:RxAndroidPlugins.setInitMainThreadSchedulerHandler{Schedulers.trampoline()}
,它现在正在工作@azizbekian指定的链接(zaglab.io)具有