Javascript 角业力测试:方法不';不改变类属性?
我很难理解为什么我的考试不及格 课程简介:Javascript 角业力测试:方法不';不改变类属性?,javascript,angular,typescript,unit-testing,karma-jasmine,Javascript,Angular,Typescript,Unit Testing,Karma Jasmine,我很难理解为什么我的考试不及格 课程简介: export class Viewer implements OnChanges { // ... selectedTimePeriod: number; timePeriods = [20, 30, 40]; constructor( /* ... */) { this.selectLastDays(15); } selectLastDays(days: number
export class Viewer implements OnChanges {
// ...
selectedTimePeriod: number;
timePeriods = [20, 30, 40];
constructor( /* ... */) {
this.selectLastDays(15);
}
selectLastDays(days: number): void { // happens on click
this.selectedTimePeriod = days;
// ...
}
}
HTML短片:
// ...
<ul>
<li *ngFor="let period of timePeriods">
<a [ngClass]="{'active': selectedTimePeriod === period}"
(click)="selectLastDays(period)">{{ period }} days
</a>
</li>
</ul>
/。。。
-
{{period}}天
测试短路:
beforeEach(() => {
fixture = TestBed.createComponent(HistoryViewerComponent);
component = fixture.componentInstance;
fixture.detectChanges();
dh = new DOMHelper(fixture);
});
it('should change selectedTimePeriod value to 20', async () => {
spyOn(component, 'selectLastDays');
dh.queryOne('li a').triggerEventHandler('click', null); // button value of 20
dh.queryOne('li a').nativeElement.click(); // clicked even twice
await fixture.whenStable();
fixture.detectChanges();
expect(component.selectLastDays).toHaveBeenCalledTimes(2); // <- true
expect(component.selectedTimePeriod).toEqual(20); // <- false
});
it('should change selectedTimePeriod', () => { // this test passes
expect(component.selectedTimePeriod).toEqual(15);
component.selectLastDays(20);
expect(component.selectedTimePeriod).toEqual(20);
});
beforeach(()=>{
fixture=TestBed.createComponent(HistoryViewerComponent);
组件=fixture.componentInstance;
fixture.detectChanges();
dh=新的DOMHelper(夹具);
});
它('应将selectedTimePeriod值更改为20',异步()=>{
spyOn(组件“selectLastDays”);
dh.queryOne('li a').triggerEventHandler('click',null);//按钮值为20
dh.queryOne('li a').nativeElement.click();//甚至单击了两次
等待fixture.whenStable();
fixture.detectChanges();
expect(component.selectLastDays).tohaveEncalledTimes(2);//第一次测试的问题是,您实际上监视selectLastDays
方法。仅使用spyOn将创建一个空存根,使函数存在,但函数不会执行任何操作
如果您需要存根来验证方法是否被调用,那么您应该告诉存根实际执行函数
it('应将selectedTimePeriod值更改为20',异步()=>{
spyOn(组件'selectLastDays')。和.callThrough();//如何将days
参数传递给selectLastDays
方法?更新了example@Smokovsky:您是否可以将控制台日志放入spec
文件并确认组件的值。选择了timeperiod
。我想应该是expect(component.selectedTimePeriod)。要成为(20)
,请注意您已将30
放入it
block expectationconsole.log(component.selectedTimePeriod)在测试方法中给出了15。是的,谢谢这30,这只是编辑、更新中的一个错误。哦,是的,谢谢:)
it('should change selectedTimePeriod value to 20', async () => {
spyOn(component, 'selectLastDays').and.callThrough(); // <= !!important
dh.queryOne('li a').triggerEventHandler('click', null); // button value of 20
dh.queryOne('li a').nativeElement.click(); // clicked even twice
await fixture.whenStable();
fixture.detectChanges();
expect(component.selectLastDays).toHaveBeenCalledTimes(2); // <- true
expect(component.selectedTimePeriod).toEqual(20); // <- false
});