如何在測試前等待異步ngOninit完成

Question

我有一個異步工作的ngOnInit方法。

異步工作完成後，如何執行我的expect語句？

it('test things once all the promises declared in ngOninit are resolved',() => { 
    comp.ngOnInit(); 

    // I want to test that comp.property is like expected 

}); 

我的組件的方法是這樣的：

OnInit() { 
    this.asyncMethod(); 
}; 

asyncMethod() { 
    this.methodThatReturnsPromise().then(() => { 
    this.property = this.otherPropertyNowResolved; 
    }) 
}; 

Answer 1

fixture = TestBed.createComponent(MyComponent); 


it('test things once all the promises declared in ngOninit are resolved', async(() => { 
     fixture.detectChanges(); 
     fixture.whenStable().then(
        () => { 
         // This should run once ngOnInit is completed 

        } 
       ); 
}));