Angular 角形8，茉莉花<；spyOn>；：找不到要监视bind（）的对象

对于我的Angular组件，我有一个基类，为了保持当前上下文，我有以下绑定代码。如果我

console.log

，我可以看到调用了

updateReference

，但jasmine无法检测是否调用了它

如果我使用以下命令，我会在标题处出错

spyOn(fixture.componentInstance.updatePreference.prototype, 'bind').and.callThrough();

我的设置有什么遗漏吗

Profile-component.ts扩展了Profile-base.ts

Profile-base.ts（基类）

剖面-组件规范ts

---

经过一些尝试和失败，我注意到它的工作，如果我重新安排顺序如下

let fixture = TestBed.createComponent(ProfileComponent);

// hold the spy reference
let spyReference = spyOn(fixture.componentInstance, updatePreference).and.callThrough();

// then trigger OnInit to do binding  
fixture.detectChanges();

// then write your expection against spy reference
expect(spyReference ).toHaveBeenCalledWith('123', '456');

public openRemovePanel(itemGuid: string, callbackFunction: (id: string, data: string) => void) { 
….
callbackFunction(id, data);
}

fit('this should work', () => {
let fixture = TestBed.createComponent(ProfileComponent);
fixture.detectChanges();

// tried both of the following
spyOn(fixture.componentInstance.updatePreference.prototype, 'bind').and.callThrough();
spyOn(fixture.componentInstance, updatePreference).and.callThrough();

…...
// make a call to openRemovePanel, and that triggers updatePreference
……

// this does not work
expect(fixture.componentInstance.updatePreference).toHaveBeenCalled();
})

let fixture = TestBed.createComponent(ProfileComponent);

// hold the spy reference
let spyReference = spyOn(fixture.componentInstance, updatePreference).and.callThrough();

// then trigger OnInit to do binding  
fixture.detectChanges();

// then write your expection against spy reference
expect(spyReference ).toHaveBeenCalledWith('123', '456');