Angular测试-未调用createSpyObj方法

Question

我有一个Angular组件和一个服务。在组件中，我有一个方法，它调用服务的一个方法。在组件测试中，我尝试为服务创建一个模拟，然后当我调用组件的方法时，我想检查是否从组件调用了服务方法。

组件:

export class TestComponent {
constructor(private testService: TestService) {}
edit(): void {
this.testService.getCase('id').subscribe(console.log);
}
}

服务:

@Injectable({
providedIn: 'root'
})
export class TestService {
constructor(
private http: HttpClient,
) { }
getCase(id: string): Observable<any> {
return this.http.get<any>(`url`);
}
}

和测试:

describe('TestComponent', () => {
let component: TestComponent;
let fixture: ComponentFixture<TestComponent>;
const testServiceMock = jasmine.createSpyObj('TestService', ['getCase']);

beforeEach(async () => {
await TestBed.configureTestingModule({
declarations: [ TestComponent ],
providers: [
{ provide: TestService, useValue: testServiceMock },
]
})
.compileComponents();
});
beforeEach(() => {
fixture = TestBed.createComponent(TestComponent);
component = fixture.componentInstance;
fixture.detectChanges();
});
it('expect service has been called', () => {
spyOn(component, 'edit');
component.edit();
expect(component.edit).toHaveBeenCalledTimes(1);
expect(testServiceMock.getCase).toHaveBeenCalled();
});
});

expect(testServiceMock.getCase).toHaveBeenCalled();

TestComponent expect service has been called FAILED Error: Expected spy TestService.getCase to have been called.

Answer 1

因为edit方法是一个间谍，所以实际的实现永远不会被调用，所以getCase间谍也永远不会被调用。为了解决这个问题，请使用edit方法spy与callThrough()。这将强制调用实际的实现。

spyOn(component,'edit').and.callThrough()

Answer 2

您需要将调用委托给实际实现:

spyOn(component, 'edit').and.callThrough();

---

https://jasmine.github.io/2.0/introduction section-Spies: _ % 3 ccode % 3 eand.callthrough % 3 c/代码% 3 e

Answer 3

您需要在第二个beforeEach()中创建注入服务，并将其设置为一个变量。

const testServiceMock = jasmine.createSpyObj('TestService', 
['getCase']);
let testServiceSpy;
beforeEach(() => {
fixture = TestBed.createComponent(TestComponent);
testServiceSpy = TestBed.inject(TestService);
component = fixture.componentInstance;
fixture.detectChanges();
});

it('expect service has been called', () => {
spyOn(component, 'edit');
component.edit();
expect(component.edit).toHaveBeenCalledTimes(1);
expect(testServiceSpy.getCase).toHaveBeenCalled();
});