Angular 如何在ionic2中使用karma/Jasmine测试异步函数？

下面我写了一段代码，其中有一个异步函数，在内部使用setTimeout（）并在3秒钟后打印消息

我得用茉莉花来写说明书

我已经遵循了，但是我不知道如何在代码中应用它

home.ts

//implementing only function written in a class.All imports are done properly.

click(){

function delayedAlert(message: string, time: number, cb) {
      return setTimeout(() => cb(message), time);
    }
    delayedAlert('Aditya3', 3000, (message) => console.log(message));//function is called
  }
}

describe('Asynchronous call', () => {
    let fixture: ComponentFixture<HomePage>;
    let comp: HomePage;
    let de: DebugElement;
    let el: HTMLElement;


    beforeEach(async(() => {
        TestBed.configureTestingModule({
            declarations: [HomePage],
            imports: [
                IonicModule.forRoot(HomePage),
            ],
            providers: [NavController],
        }).compileComponents();
    }));

    beforeEach(() => {
        fixture = TestBed.createComponent(HomePage);
        comp = fixture.componentInstance;
        de = fixture.debugElement

    });

it('Asynchronous testing with callback', ()=>{
         //how to write the spec here for the asynchronous function wrriten in the above class using Karma/Jasmine.
})
});

home.spec.ts

//implementing only function written in a class.All imports are done properly.

click(){

function delayedAlert(message: string, time: number, cb) {
      return setTimeout(() => cb(message), time);
    }
    delayedAlert('Aditya3', 3000, (message) => console.log(message));//function is called
  }
}

describe('Asynchronous call', () => {
    let fixture: ComponentFixture<HomePage>;
    let comp: HomePage;
    let de: DebugElement;
    let el: HTMLElement;


    beforeEach(async(() => {
        TestBed.configureTestingModule({
            declarations: [HomePage],
            imports: [
                IonicModule.forRoot(HomePage),
            ],
            providers: [NavController],
        }).compileComponents();
    }));

    beforeEach(() => {
        fixture = TestBed.createComponent(HomePage);
        comp = fixture.componentInstance;
        de = fixture.debugElement

    });

it('Asynchronous testing with callback', ()=>{
         //how to write the spec here for the asynchronous function wrriten in the above class using Karma/Jasmine.
})
});

description（'异步调用'，（）=>{
let夹具：组件夹具；
让comp：主页；
设de:DebugElement；
让el:HTMLElement；
beforeach（异步（（）=>{
TestBed.configureTestingModule({
声明：[主页]，
进口：[
IonicModule.forRoot（主页），
],
提供者：[NavController]，
}).compileComponents（）；
}));
在每个之前（（）=>{
fixture=TestBed.createComponent（主页）；
comp=夹具。组件状态；
de=fixture.debugElement
});
它（'使用回调进行异步测试'，（）=>{
//如何在这里使用Karma/Jasmine为上述类中的异步函数writen编写规范。
})
});

在测试规范中标记的注释中，我需要编写规范。

使用done（）方法。看看这个

---

在这篇文章中，jasmine.async lib使用了async.it等，你能帮助我在不使用jasmine.async lib的情况下编写这个规范吗？我无法实现它。你能帮我吗？