Uncaught Error: Uncaught (in promise): TypeError: this.xxxService.getSomething(...).toPromise is not a function

Question

在组件中：

private xxxService: XxxService,

const xxxList = await this.xxxService.getSomething(this.someid).toPromise();

在测试文件中component.spec.ts:

import {Observable, of} from 'rxjs';
const xxxServiceStub = {
    getSomething: () => Promise.resolve([])
  };
 beforeEach((async(next) => {
    await TestBed.configureTestingModule({
      declarations: [someComponent],
      imports: [
       ....
      ],
      providers: [
        {provide: XxxService, useValue: xxxServiceStub},
      ]
    }).compileComponents();
    next();
  }));

API:

public getSomething(someid): Observable<xxxRef[]> {
    return this.httpClient
      .get<xxxRef[]>(
        ${environment.url}/api/xxx?someid=${someid},
        {
          observe: 'response'
        }
      ).pipe(
        map(response => {
          return response.body;
        })
      );
  }

接口：

export interface xxxRef {
  name: string;
  id: number;
  description?: string;
}

测试成功，但 Karma 控制台出现错误：

zone-evergreen.js:798 Uncaught Error: Uncaught (in promise): TypeError: this.xxxService.getSomething(...).toPromise 不是函数

Answer 1

您需要 return 来自 getSomething 方法的 Observable，但您 returning Promise.resolve 而不是 Observable，这就是您出错的原因。

将您的模拟方法更改为此

import { of } from 'rxjs';

...
const xxxServiceStub = {
    getSomething: () => of([]) // this returns observable 
};

toPromise reference

mock toPromise

Answer 2

如果不知道 xxxServiceStub 是什么，很难告诉您确切的问题，但是，这可能是因为您没有返回 Observable（具有 .toPromise函数

您伪造的 xxxService.getSomething 需要看起来像这样才能在规范中工作：

getSomething(id: number): Observable<any> {
  return of(true);
}

另一种方法是使用间谍：

spyOn(xxxService, 'getSomething').and.callFake(() => of(true));

Uncaught Error: Uncaught (in promise): TypeError: this.xxxService.getSomething(...).toPromise is not a function

Uncaught Error: Uncaught (in promise): TypeError: this.xxxService.getSomething(...).toPromise is not a function

javascript

testing

karma-runner

angular