DebounceIfTest.kt

    val testScheduler = TestScheduler()

    val states = listOf(Loading, Loaded, ClickX, ClickY)

    @Test
    fun `loading followed 500ms later by loaded is emitted`() {
        val observable = Observable.fromIterable(listOf(0, 500, 1000, 2000))
            .zipWith(states) { index, state -> Pair(index, state) }
            .delay {
                Observable.timer(it.first.toLong(), TimeUnit.MILLISECONDS, testScheduler)
            }
            .map { it.second }
            .debounceIf({ it is Loading }, 250, TimeUnit.MILLISECONDS, testScheduler)

        val test = observable.test()

        testScheduler.advanceTimeTo(2000, TimeUnit.MILLISECONDS)

        test.assertResult(Loading, Loaded, ClickX, ClickY)
    }