I fairly new in Angular and TDD. Currently,I am trying to test an function on which it is called during an a resize event. Here is my following code:
header.component.ts
@Component({
selector: 'app-header',
templateUrl: './header.component.html',
styleUrls: ['./header.component.scss'],
host: {
'(window:resize)': 'onResize($event)'
}
})
export class HeaderComponent implements OnInit {
isDesktop = window.innerWidth > 768;
menuOpen = false;
constructor() {}
ngOnInit() {}
onResize(event) {
this.isDesktop = event.target.innerWidth > 768;
this.menuOpen = !this.isDesktop && this.menuOpen;
}
}
header.component.ts
describe('HeaderComponent', () => {
let component: HeaderComponent;
let fixture: ComponentFixture<HeaderComponent>;
beforeEach(async(() => {
TestBed.configureTestingModule({
declarations: [ HeaderComponent,SideMenuComponent ]
})
.compileComponents();
}));
beforeEach(() => {
fixture = TestBed.createComponent(HeaderComponent);
component = fixture.componentInstance;
fixture.detectChanges();
});
it('should create', () => {
expect(component).toBeTruthy();
})
it('should trigger onResize method when window is resized', () => {
const spyOnResize = spyOn(component, 'onResize');
window.dispatchEvent(new Event('resize'));
expect(spyOnResize).toHaveBeenCalled();
});
When I run the tests it outputs the test failed saying _<spyOn> : could not find an object to spy upon. Are there any ideas or clues to fix this problem? Any help is greatly appreciated Thank you.
