debounceEx2

debounceEx2.kt

interface View {
  fun clicks(): Observable<Unit>
}

interface Model {
  fun submits(): Observable<Unit>
}

class Presenter(val view: View, val model: Model) {
   fun setUp() {
     view
       .debounce(100, TimeUnit.MILLISECONDS)
       .flatMap { model.submits() }
       .susbscribe()
   }
}

class PresenterTest {
  @InjectMocks
  lateinit var testSubject: Presenter
  
  @Mock
  lateinit var view: View
  
  @Mock
  lateinit var model: Model
  
  @Test
  fun viewClicks_onlySumbitsOneEventPer115Ms() {
    // GIVEN
    val scheduler = setUpRxComputationScheduler()
    val subject = PublishSubject<Unit>()
    whenever(view.clicks()).thenReturn(subject)
    testSubject.setUp()
    
    // WHEN
    subject.onNext(Unit)
    subject.onNext(Unit)
    subject.onNext(Unit)
    scheduler.advanceBy(115, TimeUnit.MILLISECONDS)
    subject.onNext(Unit)
    subject.onNext(Unit)
    subject.onNext(Unit)
    scheduler.advanceBy(230, TimeUnit.MILLISECONDS)
    
    
    // THEN
    verify(model, times(2)).submit()
    
  }
  
  fun setUpRxComputationScheduler(): TestScheduler {
    val scheduler = TestScheduler()
    RxJavaPlugins.getInstance().reset()
    RxJavaPlugins.getInstance().registerSchedulersHook(object : RxJavaSchedulersHook() {
        override fun getComputationScheduler(): Scheduler {
            return scheduler
        }
    })
    return scheduler
  }
}