使用MockBackend来测试函数，然后调用.map

Question

我想为我的服务编写Http请求的单元测试。

我有一项服务返回一个Http.get()请求后跟一个.map()。我无法让我的模拟后端返回.map()上没有错误的内容。我得到的错误是：

this._http.get(...).map is not a function 

我一直在使用this article作为我的主要指导贯穿始终。

如果我从我的服务功能中删除.map()，我不会收到任何错误。我怎样才能让我的嘲弄反应有一个我可以调用的.map()函数？

注：我目前使用的RC.4

这里是我的服务：

import { Injectable } from '@angular/core'; 
import { Http, Response } from '@angular/http'; 
import { Observable } from 'rxjs/Observable'; 

import { AppSettings } from '../../../settings'; 
import { Brand } from '../../models/index'; 

@Injectable() 
export class BrandDataService { 

    allBrands : Brand[]; 
    groups : any; 
    groupNames : string[]; 

    constructor (
    private _http : Http 
) {} 

    /** 
    * Get all brands 
    */ 
    public getAllBrands() :Observable<any> { 

    let url = AppSettings.BRAND_API_URL + 'brands'; 
    return this._http.get(url) 
    .map(this.createAndCacheBrands) 
    .catch((error) => { 
     return Observable.throw(error); 
    });   
    } 

    private createAndCacheBrands (res:Response) { 
    ... 
    } 

} 

这里是我的规格文件，该文件是使用MockBackend和其他相关库嘲笑后端这些测试：

// vendor dependencies 
import { Http, BaseRequestOptions, Response, ResponseOptions, RequestMethod } from '@angular/http'; 
import { addProviders, inject } from '@angular/core/testing'; 
import { MockBackend, MockConnection } from '@angular/http/testing'; 

// Service to test 
import { BrandDataService } from './brandData.service'; 


describe('Brand data service',() => { 

    let service : BrandDataService = null; 
    let backend : MockBackend = null; 

    // Provide a mock backend implementation 
    beforeEach(() => { 
    addProviders([ 
     MockBackend, 
     BaseRequestOptions, 
     { 
     provide : Http, 
     useFactory : (backendInstance : MockBackend, defaultOptions : BaseRequestOptions) => { 
      return new Http(backendInstance, defaultOptions); 
     }, 
     deps : [MockBackend, BaseRequestOptions] 
     }, 
     BrandDataService 
    ]) 
    }) 

    beforeEach (inject([BrandDataService, MockBackend], (_service : BrandDataService, mockBackend : MockBackend) => { 
    service = _service; 
    backend = mockBackend; 
    })); 

    it ('should return all brands as an Observable<Response> when asked', (done) => { 
    // Set the mock backend to respond with the following options: 
backend.connections.subscribe((connection : MockConnection) => { 
    // Make some expectations on the request 
    expect(connection.request.method).toEqual(RequestMethod.Get); 
    // Decide what to return 
    let options = new ResponseOptions({ 
     body : JSON.stringify({ 
     success : true 
     }) 
    }); 
    connection.mockRespond(new Response(options)); 
    }); 

    // Run the test. 
    service 
    .getAllBrands() 
    .subscribe(
    (data) => { 
     expect(data).toBeDefined(); 
     done(); 
    } 
) 
    }); 
}); 

Answer 1

您需要导入rxjs所以你可以使用map：

import 'rxjs/Rx'; 

或者，您可以只导入map操作让你的应用程序不加载文件，你不会使用：

import 'rxjs/add/operator/map';