[英]How do I trigger a ngModel model update in an Angular 2 unit test?
[英]How do I trigger a keyboard event in an Angular 2+ unit test?
我有一個Angular 4組件,可以監聽用戶按下箭頭鍵的情況。 我已將其重新創建為計數器的演示,可以使用向上和向下鍵遞增或遞減。
export enum KEY_CODE {
RIGHT_ARROW = 39,
LEFT_ARROW = 37
};
export class AppComponent {
counter = 0;
@HostListener('window:keyup', ['$event'])
handleKeypress(event: KeyboardEvent) {
if (event.keyCode === KEY_CODE.UP_ARROW) {
this.counter++;
} else if (event.keyCode === KEY_CODE.DOWN_ARROW) {
this.counter--;
}
}
}
我在單元測試中檢查此行為:
it('should increment when you push the "up" key', () => {
const fixture = TestBed.createComponent(AppComponent);
const app = fixture.debugElement.componentInstance;
expect(app.counter).toBe(0);
let upKeyPress = {keyCode: KEY_CODE.UP_ARROW};
fixture.debugElement.triggerEventHandler('keyup', upKeyPress);
expect(app.counter).toBe(1);
});
該測試失敗。 計數器不增加。 這是為什么?
柱塞: https ://plnkr.co/edit/sNtQMH82Tk2siKueBDT5 ? p = preview
嘗試這個:
fixture.debugElement.triggerEventHandler('keyup.uparrow', {}});
我還沒有找到一種通過debugElement做到這一點的方法,但是我使用window對象使其工作了:
let upPress = new KeyboardEvent('keyup', {code: 'ArrowUp'});
window.dispatchEvent(upPress);
考慮,我有類名為“ .search-input”的輸入字段,然后
const element = fixture.debugElement.query(By.css('.search-input'));
element.nativeElement.dispatchEvent(new KeyboardEvent('keyup', {code: 'ArrowUp'}));
fixture.detectChanges();
這就是我的方法,對我有用。
聲明:本站的技術帖子網頁,遵循CC BY-SA 4.0協議,如果您需要轉載,請注明本站網址或者原文地址。任何問題請咨詢:yoyou2525@163.com.