• 替代HTTP Mock策略

    替代HTTP Mock策略

    使用MockBackend的一个替代方法是创建我们自己的轻模拟。 这里我们创建一个对象，然后告诉TypeScript使用类型断言将其视为Http 。 然后我们为它的get方法创建一个监测器，并返回一个类似于真正的Http服务的observable 。

    此方法仍然允许我们检查服务是否已请求正确的URL，并返回预期的数据。

    wikisearch.spec.ts

    1. import {
    2.   fakeAsync,
    3.   inject,
    4.   TestBed
    5. } from '@angular/core/testing';
    6. import {
    7.   HttpModule,
    8.   Http,
    9.   ResponseOptions,
    10.   Response
    11. } from '@angular/http';
    12. import { Observable } from 'rxjs/Observable';
    13. import 'rxjs/add/observable/of';
    14. import {SearchWiki} from './wikisearch.service';
    16. const mockResponse = {
    17.   "batchcomplete": "",
    18.   "continue": {
    19.     "sroffset": 10,
    20.     "continue": "-||"
    21.   },
    22.   "query": {
    23.     "searchinfo": {
    24.       "totalhits": 36853
    25.     },
    26.     "search": [{
    27.       "ns": 0,
    28.       "title": "Stuff",
    29.       "snippet": "<span></span>",
    30.       "size": 1906,
    31.       "wordcount": 204,
    32.       "timestamp": "2016-06-10T17:25:36Z"
    33.     }]
    34.   }
    35. };
    37. describe('Wikipedia search service', () => {
    38.   let mockHttp: Http;
    40.   beforeEach(() => {
    41.     mockHttp = { get: null } as Http;
    43.     spyOn(mockHttp, 'get').and.returnValue(Observable.of({
    44.       json: () => mockResponse
    45.     }));
    47.     TestBed.configureTestingModule({
    48.       imports: [HttpModule],
    49.       providers: [
    50.         {
    51.           provide: Http,
    52.           useValue: mockHttp
    53.         },
    54.         SearchWiki
    55.       ]
    56.     });
    57.   });
    59.   it('should get search results', fakeAsync(
    60.     inject([SearchWiki], searchWiki => {
    61.       const expectedUrl = 'https://en.wikipedia.org/w/api.php?' +
    62.         'action=query&list=search&srsearch=Angular';
    64.       searchWiki.search('Angular')
    65.         .subscribe(res => {
    66.           expect(mockHttp.get).toHaveBeenCalledWith(expectedUrl);
    67.           expect(res).toEqual(mockResponse);
    68.         });
    69.     })
    70.   ));
    72. });

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