Android 方法内部的单元测试RxJava+改型调用

我要测试的方法包含对改装服务的两个调用：

 internal fun poll(): Completable {
    return presenceService.askForFrequency(true).toObservable()
            .flatMap { it -> Observable.interval(it.frequency, TimeUnit.SECONDS, Schedulers.io()) }
            .flatMapCompletable { _ -> presenceService.sendHeartbeat() }
            .subscribeOn(Schedulers.io())
            .retry()
}

presenceService被注入类中，因此我为测试提供模拟服务：

val frequency = PublishSubject.create<Presence>()
val heartbeat = PublishSubject.create<Unit>()
val mockPresenceService = mock<PresenceService> {
    on { askForFrequency(any()) } doReturn frequency
    on { sendHeartbeat() } doReturn heartbeat
}

单元测试运行的日志包括：

Wanted but not invoked:
presenceService.sendHeartbeat();

However, there was exactly 1 interaction with this mock:
presenceService.askForFrequency(true);

问题是：如何测试第二个方法sendHeartbeat是否也被调用过几次

同时我发现问题出在第二个平面图上，因为该方法的测试正确地验证了该方法被调用了60次：

 internal fun pollTest(): Observable<Presence> {
    return Observable.interval(1, TimeUnit.SECONDS, Schedulers.io())
            .subscribeOn(Schedulers.io())
            .flatMap { it -> presenceService.askForFrequency(true).toObservable() }
}

@Test
fun presenceService_sentHeartbeat() {
    frequency.onNext(Presence(1))
    val result = arrayListOf<Unit>()
    presenceMaintainer.pollTest().subscribe({ t -> result.add(Unit) })
    Thread.sleep(60*1000)
    println(result.size)
    verify(mockPresenceService, Times(60)).askForFrequency(true)
}

---

但当我将调用顺序更改为askForFrequency->map to interval->map each tick to poll调用时，test停止工作，mock只被调用一次

默认情况下，Observable.interval在计算调度程序上运行，而不是在io调度程序上运行。这意味着，2秒的等待将实时运行，因此您的测试将在调用sendHeartBeat前2秒完成。

谢谢！但是，如果我在间隔调用中添加RxJavaPlugins.setComputationSchedulerHandler{scheduler}或指定Schedulers.io，它也不起作用。虽然设置起来可能很麻烦，但我自己的经验是将间隔、延迟、去盎司操作符将运行的时间传递给调度器。它使测试更容易。

 internal fun pollTest(): Observable<Presence> {
    return Observable.interval(1, TimeUnit.SECONDS, Schedulers.io())
            .subscribeOn(Schedulers.io())
            .flatMap { it -> presenceService.askForFrequency(true).toObservable() }
}

@Test
fun presenceService_sentHeartbeat() {
    frequency.onNext(Presence(1))
    val result = arrayListOf<Unit>()
    presenceMaintainer.pollTest().subscribe({ t -> result.add(Unit) })
    Thread.sleep(60*1000)
    println(result.size)
    verify(mockPresenceService, Times(60)).askForFrequency(true)
}