Angular 2 - Mock Observable（服務元件）

服務

• 我用 postRequest 方法建立了 post service。

import {Injectable} from '@angular/core';
import {Http, Headers, Response} from "@angular/http";
import {PostModel} from "./PostModel";
import 'rxjs/add/operator/map';
import {Observable} from "rxjs";

@Injectable()
export class PostService {

  constructor(private _http: Http) {
  }

  postRequest(postModel: PostModel) : Observable<Response> {
      let headers = new Headers();
      headers.append('Content-Type', 'application/json');
    return this._http.post("/postUrl", postModel, {headers})
      .map(res => res.json());
  }
}

零件

• 我建立了帶有結果引數的元件和呼叫 postService 的 postExample 函式。
• 當 post resquest 成功而不是 result 引數應該是’Success’否則’Fail'

import {Component} from '@angular/core';
import {PostService} from "./PostService";
import {PostModel} from "./PostModel";

@Component({
  selector: 'app-post',
  templateUrl: './post.component.html',
  styleUrls: ['./post.component.scss'],
  providers : [PostService]
})
export class PostComponent{

  constructor(private _postService : PostService) {
    
  let postModel = new PostModel();
  result : string = null;
  postExample(){
    this._postService.postRequest(this.postModel)
      .subscribe(
        () =>  {
          this.result = 'Success';
        },
        err =>  this.result = 'Fail'
      )
  }
}

測試服務

• 當你想測試使用 http 的服務時你應該使用 mockBackend。並注入它。
• 你還需要注入 postService。

describe('Test PostService', () => {
  beforeEach(() => {
    TestBed.configureTestingModule({
      imports: [HttpModule],
      providers: [
        PostService,
        MockBackend,
        BaseRequestOptions,
        {
          provide: Http,
          deps: [MockBackend, BaseRequestOptions],
          useFactory: (backend: XHRBackend, defaultOptions: BaseRequestOptions) => {
            return new Http(backend, defaultOptions);
          }
        }
      ]
    });
  });

  it('sendPostRequest function return Observable', inject([PostService, MockBackend], (service: PostService, mockBackend: MockBackend) => {
    let mockPostModel = PostModel();

    mockBackend.connections.subscribe((connection: MockConnection) => {
      expect(connection.request.method).toEqual(RequestMethod.Post);
      expect(connection.request.url.indexOf('postUrl')).not.toEqual(-1);
      expect(connection.request.headers.get('Content-Type')).toEqual('application/json');
    });

    service
      .postRequest(PostModel)
      .subscribe((response) => {
        expect(response).toBeDefined();
      });
  }));
});

測試元件

describe('testing post component', () => {
  let component: PostComponent;
  let fixture: ComponentFixture<postComponent>;

  let mockRouter = {
    navigate: jasmine.createSpy('navigate')
  };

  beforeEach(async(() => {
    TestBed.configureTestingModule({
      declarations: [PostComponent],
      imports: [RouterTestingModule.withRoutes([]),ModalModule.forRoot() ],
      providers: [PostService ,MockBackend,BaseRequestOptions,
        {provide: Http, deps: [MockBackend, BaseRequestOptions],
          useFactory: (backend: XHRBackend, defaultOptions: BaseRequestOptions) => {
            return new Http(backend, defaultOptions);
          }
        },
        {provide: Router, useValue: mockRouter}
      ],
      schemas: [ CUSTOM_ELEMENTS_SCHEMA ]
    }).compileComponents();
  }));

  beforeEach(() => {
    fixture = TestBed.createComponent(PostComponent);
    component = fixture.componentInstance;
    fixture.detectChanges();
  });

  

  it('test postRequest success', inject([PostService, MockBackend], (service: PostService, mockBackend: MockBackend) => {
    fixturePostComponent = TestBed.createComponent(PostComponent);
    componentPostComponent = fixturePostComponent.componentInstance;
    fixturePostComponent.detectChanges();

    component.postExample();
    let postModel = new PostModel();
    let response = {
      'message' : 'message',
      'ok'      : true
    };
    mockBackend.connections.subscribe((connection: MockConnection) => {
      postComponent.result = 'Success'
      connection.mockRespond(new Response(
        new ResponseOptions({
          body: response
        })
      ))
    });
    service.postRequest(postModel)
      .subscribe((data) => {
        expect(component.result).toBeDefined();
        expect(PostComponent.result).toEqual('Success');
        expect(data).toEqual(response);
      });
  }));
});