Angular 2 JWT单元测试

Question

我的API调用使用JWT进行身份验证。我正在尝试编写一个服务方法的代码。所有请求都有这个拦截器：

public interceptBefore(request: InterceptedRequest): InterceptedRequest {
        // Do whatever with request: get info or edit it
        this.slimLoadingBarService.start();
        let currentUser = JSON.parse(localStorage.getItem('currentUser'));
        if (currentUser && currentUser.data.token) {
            request.options.headers.append('Authorization', 'Bearer ' + currentUser.data.token);
        }
        return request;
    }

我想要测试的服务方法：

getAll(page: number, pageSize: number, company: string): Observable<any> {
        return this.http.get(`${this.conf.apiUrl}/jobs`)
            .map((response: Response) => response.json());
    }

开始编写代码：

import { MockBackend, MockConnection } from '@angular/http/testing';
import { Http, BaseRequestOptions, Response, ResponseOptions, RequestMethod } from '@angular/http';
import { JobListService } from './job-list.service';
import { inject, TestBed } from '@angular/core/testing/test_bed';
import { JOBLISTMOCK } from '../mocks/job-list.mock';

fdescribe('Service: JobListService', () => {
    beforeEach(() => {
        TestBed.configureTestingModule({
            providers: [
                JobListService,
                MockBackend,
                BaseRequestOptions,
                {
                    provide: Http,
                    useFactory: (backend: MockBackend, defaultOptions: BaseRequestOptions) => {
                        return new Http(backend, defaultOptions);
                    },
                    deps: [MockBackend, BaseRequestOptions]
                },
            ]
        });
    });

    it('should create a service', inject([JobListService], (service: JobListService) => {
        expect(service).toBeTruthy();
    }));

    describe('getAll', () => {
        it('should return jobs', inject([JobListService, MockBackend], (service: JobListService, backend: MockBackend) => {
            let response = new ResponseOptions({
                body: JSON.stringify(JOBLISTMOCK)
            });

            const baseResponse = new Response(response);

            backend.connections.subscribe(
                (c: MockConnection) => c.mockRespond(baseResponse)
            );

            return service.getAll(1, 10, '18').subscribe(data => {
                expect(data).toEqual(JOBLISTMOCK);
            });
        }));
    });
});

不知道如何对拦截器进行测试。

PS：由于当前的测试，会出现错误：

1) should create a service
     JobListService
     TypeError: null is not an object (evaluating 'this.platform.injector') in src/test.ts (line 83858)
_createCompilerAndModule@webpack:///~/@angular/core/testing/test_bed.js:254:0 <- src/test.ts:83858:44

2) should return jobs
     JobListService getAll
     TypeError: null is not an object (evaluating 'this.platform.injector') in src/test.ts (line 83858)
_createCompilerAndModule@webpack:///~/@angular/core/testing/test_bed.js:254:0 <- src/test.ts:83858:44

- yretuta

Answer 1

类型错误：null不是一个对象（评估'this.platform.injector'时）

通常，如果您没有正确初始化测试环境，您将会收到此错误。您可以通过执行以下操作解决此问题：

import {
  BrowserDynamicTestingModule, platformBrowserDynamicTesting
} from '@angular/platform-browser-dynamic/testing';
...
beforeAll(() => {
  TestBed.initTestEnvironment(
    BrowserDynamicTestingModule,
    platformBrowserDynamicTesting()
  );
});

这件事情需要注意的是，它应该仅在整个测试套件执行期间被调用一次。因此，如果您在每个测试文件中都有它，那么您需要先在每个文件中重置它。

beforeAll(() => {
  TestBed.resetTestEnvironment();
  TestBed.initTestEnvironment(
    BrowserDynamicTestingModule,
    platformBrowserDynamicTesting()
  );
});

更好的做法是不在每个测试文件中添加它。如果您查看Angular文档中有关Webpack集成的部分，在测试部分，您将看到一个名为karma-test-shim.js的文件。在这个文件中，推荐的方法来初始化测试环境。

Error.stackTraceLimit = Infinity;

require('core-js/es6');
require('core-js/es7/reflect');

require('zone.js/dist/zone');
require('zone.js/dist/long-stack-trace-zone');
require('zone.js/dist/proxy');
require('zone.js/dist/sync-test');
require('zone.js/dist/jasmine-patch');
require('zone.js/dist/async-test');
require('zone.js/dist/fake-async-test');

var appContext = require.context('../src', true, /\.spec\.ts/);

appContext.keys().forEach(appContext);

var testing = require('@angular/core/testing');
var browser = require('@angular/platform-browser-dynamic/testing');

testing.TestBed.initTestEnvironment(browser.BrowserDynamicTestingModule,
    browser.platformBrowserDynamicTesting());

你可以在底部看到我们进行了与上文相同的初始化调用。你应该将这个文件添加到配置文件karma.conf.js中的files数组中。这是来自上面链接的文档。

files: [
  {pattern: './config/karma-test-shim.js', watched: false}
],

preprocessors: {
  './config/karma-test-shim.js': ['webpack', 'sourcemap']
},

- Paul Samsotha