it('should stop emitting events to disposed overlays', () => {
    const instance = overlay.create();
    const spy = jasmine.createSpy('keyboard event spy');

    instance.attach(new ComponentPortal(TestComponent));
    instance.keydownEvents().subscribe(spy);

    dispatchKeyboardEvent(document.body, 'keydown', ESCAPE, instance.overlayElement);
    expect(spy).toHaveBeenCalledTimes(1);

    instance.dispose();
    dispatchKeyboardEvent(document.body, 'keydown', ESCAPE, instance.overlayElement);

    expect(spy).toHaveBeenCalledTimes(1);
  });

  it('should skip overlays that do not have keydown event subscriptions', () => {
    const overlayOne = overlay.create();
    const overlayTwo = overlay.create();
    const overlayOneSpy = jasmine.createSpy('overlayOne keyboard event spy');

    overlayOne.keydownEvents().subscribe(overlayOneSpy);
    keyboardDispatcher.add(overlayOne);
    keyboardDispatcher.add(overlayTwo);

    dispatchKeyboardEvent(document.body, 'keydown', ESCAPE);

    expect(overlayOneSpy).toHaveBeenCalled();
  });

  it('should not clear the focus origin too early in the current event loop', fakeAsync(() => {
    dispatchKeyboardEvent(document, 'keydown', TAB);

    // Simulate the behavior of Firefox 57 where the focus event sometimes happens *one* tick later.
    tick();

    buttonElement.focus();

    // Since the timeout doesn't clear the focus origin too early as with the `0ms` timeout, the
    // focus origin should be reported properly.
    expect(changeHandler).toHaveBeenCalledWith('keyboard');

    flush();
  }));

  it('should detect focus via keyboard', fakeAsync(() => {
    // Simulate focus via keyboard.
    dispatchKeyboardEvent(document, 'keydown', TAB);
    buttonElement.focus();
    fixture.detectChanges();
    tick();

    expect(buttonElement.classList.length)
        .toBe(2, 'button should have exactly 2 focus classes');
    expect(buttonElement.classList.contains('cdk-focused'))
        .toBe(true, 'button should have cdk-focused class');
    expect(buttonElement.classList.contains('cdk-keyboard-focused'))
        .toBe(true, 'button should have cdk-keyboard-focused class');
    expect(changeHandler).toHaveBeenCalledWith('keyboard');
  }));

  it('should select the option when pressing space', () => {
    const fixture = TestBed.createComponent(BasicOption);
    fixture.detectChanges();

    const optionDebugElement = fixture.debugElement.query(By.directive(MatOption));
    const optionNativeElement: HTMLElement = optionDebugElement.nativeElement;
    const optionInstance: MatOption = optionDebugElement.componentInstance;
    const spy = jasmine.createSpy('selection change spy');
    const subscription = optionInstance.onSelectionChange.subscribe(spy);

    const event = dispatchKeyboardEvent(optionNativeElement, 'keydown', SPACE);
    fixture.detectChanges();

    expect(spy).toHaveBeenCalled();
    expect(event.defaultPrevented).toBe(true);
    subscription.unsubscribe();
  });