将单元测试用例写入 promise 函数时未发生代码覆盖率

Question

我正在使用角度6和Jasmine编写单元测试用例。在下面的代码函数上编写小测试用例后，我无法覆盖getUserJSON函数。如何覆盖孔函数以获得此函数的代码覆盖率的完整百分比。

export class UserLoginService implements OnDestroy {

// Store the userdata
getUserDatafromSubject(userData: IUser) {
this.userData.next(userData);
}
//To get LoggedIn User Deatils
getUserJSON(): Promise<boolean> {
return new Promise<boolean>((resolve) => {
this._servSub = this.http.get<IUser>(/*environment.appBaseUrl + 'Account/LogIn' */'api/homepage/user.json').subscribe(value => {
value.selAssetClass = 'COM';
if (!value.userId || !value.userName || value.userAsset.length === 0 || value.pageAccess.length === 0) {
value.isAuthorized = false;
} else {
value.isAuthorized = true;
}
this.getUserDatafromSubject(value);
resolve(true);
})
});
}

我的规范文件如下：

import { TestBed, inject, async } from '@angular/core/testing';
import { UserLoginService } from './user-login.service';
import { HttpClientTestingModule, HttpTestingController } from '@angular/common/http/testing';

describe('UserLoginService', () => {
let service: UserLoginService;
let httpMock: HttpTestingController;
beforeEach(() => {
TestBed.configureTestingModule({
providers: [UserLoginService],
imports: [HttpClientTestingModule],
});
service = TestBed.get(UserLoginService);
httpMock = TestBed.get(HttpTestingController);
});

it('should call getUserJSON from apiService', function(done) {
spyOn(service, 'getUserJSON').and.returnValue(Promise.resolve(true));
service.getUserJSON()
.then((result) => {     
expect(result).toEqual(true);
expect(service.getUserJSON).toHaveBeenCalled();             
done();
});
});
});

我的测试用例通过正常，但无法完全覆盖代码。我想完全涵盖getUserJSON功能。有什么帮助吗？

Answer 1

您正在监视getUserJSON并返回一个值。当你这样做时，实际的函数永远不会被执行，而是被调用间谍。这就是您看不到覆盖范围的原因。

若要调用实际的getUserJSON函数并仍然监视它，请将spyOn调用替换为以下代码：

spyOn(service, 'getUserJSON').and.callThrough();