Angular单元测试TypeError: this.http.get(...).pipe不是函数
Angular单元测试TypeError: this.http.get(...).pipe不是函数
提问于 2018-06-20 20:40:43
我将按照这个示例为服务(来自spring应用后端的get请求) https://angular.io/guide/testing#testing-http-services进行单元测试
服务类别：
@Injectable()
export class TarifService {
constructor(private messageService: MessageService, private http: HttpClient) { }
public getTarifs(): Observable<Tarif[]> {
return this.http.get<Tarif[]>(tarifffsURL).pipe(
tap(() => {}),
catchError(this.handleError('getTarifs', []))
);
}
}单元测试
describe('TarifService', () => {
let tarifService: TarifService;
let httpClientSpy: { get: jasmine.Spy };
let expectedTarifs;
beforeEach(() => {
TestBed.configureTestingModule({
imports: [ToastrModule.forRoot(), HttpClientModule, HttpClientTestingModule],
providers: [TarifService, HttpClient, MessageService]
});
httpClientSpy = jasmine.createSpyObj('HttpClient', ['get']);
tarifService = new TarifService(<any> MessageService,<any> httpClientSpy);
});
it('should be created', inject([TarifService], (service: TarifService) => {
expect(service).toBeTruthy();
}));
it('should return expected tarif (HttpClient called once)', () => {
const expectedTarifs: Tarif[] =
[{ id: 1, name: 'Tarif1', value: '20' }, { id: 2, name: 'Tarif2', value:'30' }];
httpClientSpy.get.and.returnValue(expectedTarifs);
tarifService.getTarifs().subscribe(
tarifs => expect(tarifs).toEqual(expectedTarifs, 'expected tarifs'),
fail
);
expect(httpClientSpy.get.calls.count()).toBe(1, 'one call');
});
});在运行测试时，我总是遇到这样的错误
TarifService should return expected tarif (HttpClient called once)
TypeError: this.http.get(...).pipe is not a function这可能是什么原因呢？
回答 2
Stack Overflow用户
发布于 2018-06-21 04:51:42
问题是，当您的spy被调用时，它返回一个Array，而Array没有pipe函数。您需要从spy返回一个Observable，如下所示
const expectedTarifs: Tarif[] =
[{ id: 1, name: 'Tarif1', value: '20' }, { id: 2, name: 'Tarif2', value:'30' }];
httpClientSpy.get.and.returnValue(Observable.of(expectedTarifs));看看returnValue是如何Observable.of(expectedTarifs)的。Observable.of创建了一个Observable，它会一个接一个地发出您指定为参数的一些值，然后发出完整的通知。See the docs
在最新版本的rxjs中，我们可以使用of运算符
import { of } from 'rxjs';
//... omitting some code here for brevity
const expectedTarifs: Tarif[] =
[{ id: 1, name: 'Tarif1', value: '20' }, { id: 2, name: 'Tarif2', value:'30' }];
httpClientSpy.get.and.returnValue(of(expectedTarifs));希望能有所帮助
Stack Overflow用户
发布于 2020-04-21 22:40:22
为了让我的系统正常工作，我不得不这样做：
import { from } from 'rxjs';然后：
return from([expectedTarifs]);页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/50948524
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