相关疑难解决方法(0)

我想使用间谍测试选择 onChange 事件，但出现错误

Expected spy onSelect to have been called with [ 'en' ] but actual calls were [ '' ].

成分

@Component({
  selector: 'tnos-languages',
  templateUrl: './languages.component.html',
  styleUrls: ['./languages.component.scss'],
  changeDetection: ChangeDetectionStrategy.OnPush
})
export class LanguagesComponent {
  @Input() languages: Language[];
  @Output()
  change: EventEmitter<string> = new EventEmitter<string>();
  constructor() { }
  onSelect(locale: string) {
    this.change.emit(locale);
  }
}

模板

<select #selectLanguage (change)="onSelect(selectLanguage.value)">
  <option  *ngFor="let language of languages" [value]="language.locale">
    {{language.label}}
  </option>
</select>

测试

const languages: Language[] = [{
  id: 1,
  label: 'Italiano',
  locale: 'it',
  default: …