如何在 angular 中为 setTimeout function 和 activeElement 编写单元测试？

Question

I want to write a unit test case for the following function:

onfactorblur():void{
  var that=this;
  setTimeout(function(){
    var target=document.activeElement;
    if(target.tagName=="BUTTON"){
      if(target.textContent=="CONTINUE"){
        that.onContinueClick();
      }
      else{
        that.activeModal.close();
      }
     }
   },.5);
 }

I am new to angular unit testing and never faced a scenario where I had to test setTimeout within a function. I have tried:

    it('Should close the modal if target element is button',fakeAsync(()=>{
    spyOn(component,'onContinueClick');
    spyOn(component.activeModal,'close');
    tick(1);
    fixture.detectChanges();
    fixture.whenStable().then(()=>{
    //What should I write here
      })
    }));

Answer 1

You can use fakeAsync , you can call tick(500) to simulates the asynchronous passage of time more details here https://angular.io/guide/testing-components-scenarios#async-test-with-fakeasync