javascript - 应该调用 ngOnInit 内部的函数

Question

我是 Angular Testing 的新手，我想知道如何测试 ngOnInit 调用时调用的函数。下面是我正在尝试测试的代码

it('should call TestMethod method inside ngOnInit' , async() => {
    spyOn(component , 'TestMethod')
    fixture.detectChanges()
    expect(component.TestMethod).toHaveBeenCalled()
  })

下面是我收到的错误

Expected spy TestMethod to have been called.

BeforeEach 位于下方

beforeEach(() => {
    fixture = TestBed.createComponent(CreateRoomsComponent);
    component = fixture.componentInstance;
    fixture.detectChanges();
  });

Answer 1

将 spy 对象分配给变量并在expect函数中使用该变量

    it('should call TestMethod method inside ngOnInit' , async() => {
    const obj = spyOn(component , 'TestMethod')
    fixture.detectChanges()
    expect(obj).toHaveBeenCalled()
  })