我一直面临主题和 TestScheduler 的问题。如果我使用 Trampoline 调度程序,我的测试会通过,但由于某种原因,如果我使用 TestScheduler,测试会失败。
这是我的示例测试和相关类(class)。
@RunWith(MockitoJUnitRunner::class)
class DemoViewModelTest {
//Error Mocks
private val actionsStream: PublishSubject<DemoContract.ViewEvent> = PublishSubject.create()
private lateinit var viewModel: DemoViewModel
private val handler = mock(DemoContract.Handler::class.java)
@Before
fun setup() {
viewModel = DemoViewModel(schedulersProvider, handler)
viewModel.viewEventsStream = actionsStream
}
@Test
fun testUpdateCounter() {
actionsStream.onNext(DemoContract.ViewEvent.UpdateClick)
testScheduler.triggerActions()
verify(handler).onUpdate()
}
protected var testScheduler = TestScheduler()
protected var schedulersProvider: SchedulersProvider = object : SchedulersProvider() {
override fun mainThread(): Scheduler {
return testScheduler
}
override fun io(): Scheduler {
return testScheduler
}
override fun computation(): Scheduler {
return testScheduler
}
override fun newThread(): Scheduler {
return testScheduler
}
override fun trampoline(): Scheduler {
return testScheduler
}
override fun single(): Scheduler {
return testScheduler
}
}
}
还有我的 ViewModel 类
class DemoViewModel (val schedulersProvider: SchedulersProvider, val handler:DemoContract.Handler) : DemoContract.ViewModel() {
var viewEventsStream: Observable<DemoContract.ViewEvent>? = null
set(value) {
field = value
subscribeToViewEvents()
}
private fun subscribeToViewEvents() {
viewEventsStream?.let {
it.subscribeOn(schedulersProvider.io())
.observeOn(schedulersProvider.mainThread())
.subscribe(object:Observer<DemoContract.ViewEvent>{
override fun onComplete() {
}
override fun onSubscribe(d: Disposable) {
}
override fun onNext(t: DemoContract.ViewEvent) {
onViewEvent(t)
}
override fun onError(e: Throwable) {
}
})
}
}
fun onViewEvent(event: DemoContract.ViewEvent) {
when (event) {
is DemoContract.ViewEvent.UpdateClick -> {
handler.onUpdate()
}
}
}
}
我的契约(Contract)类别是
interface DemoContract {
abstract class ViewModel
sealed class ViewEvent {
object UpdateClick : ViewEvent()
}
interface Handler{
fun onUpdate()
}
}
关于这个的一些事情,如果我更换
viewModel.viewEventsStream = actionsStream
与
viewModel.viewEventsStream = Observable.just(DemoContract.ViewEvent.Update)
此测试通过。
有人可以解释一下吗,提前致谢。这是最小可运行的 project
最佳答案
非常感谢@akarnokd 为我指明了正确的方向。事实证明,这是添加的 PublishSubject 的订阅者(subscribeActual
调用)与我在测试中触发的 onNext 调用之间的竞争条件。 onNext
调用在前者发生之前返回。
解决方案是显式调用 triggerActions
两次,一次在订阅后立即调用,一次在发射后调用。
改变这个
@Before
fun setup() {
viewModel = DemoViewModel(schedulersProvider, handler)
viewModel.viewEventsStream = actionsStream
}
至
@Before
fun setup() {
viewModel = DemoViewModel(schedulersProvider, handler)
viewModel.viewEventsStream = actionsStream
testScheduler.triggerActions()
}
关于android - PublishSubject 和 TestScheduler 出现问题,未发出项目,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/53519339/