使用模拟后端测试HTTP [英] Testing HTTP with mockbackends

问题描述

我正在为Angular 2中的服务构建测试.事实证明，构建模拟后端是一个真正的尝试.我已经能够成功发出实际的HTTP请求来测试服务，但我希望将它们与第三部分分开.

I'm working on building out tests for my services in Angular 2. Building out the mock backends is proving to be a real trial. I have been able to test the services with it making actual HTTP requests successfully but I would like to keep these segregated from the third part.

我仔细阅读了我能找到的两篇主要文章(第一，秒以及角度文档.

I've combed through the two main articles I have been able to find (first, second as well as the angular docs.

当我向实际的第三方服务成功发出http请求时，必须使用done();以确保测试等待请求完成.似乎这里的情况是一样的.如果我不使用它，即使使用expect(1).toBe(2);，测试也将成功.当我使用它时，它会等待呼叫完成而超时.错误:

When I was making successful http requests to actual third party services, I had to use done(); to ensure that the test waited for the request to complete. It seems that the case is the same here. If I do not use it, the test will be a success even with expect(1).toBe(2);. When I do use it, it times out waiting for the call to complete. Error:

Error: Timeout - Async callback was not invoked within timeout specified by jasmine.DEFAULT_TIMEOUT_INTERVAL.

这是我的代码:

import {
    it,
    inject,
    describe,
    beforeEachProviders,
    expect,
} from '@angular/core/testing';
import { BaseRequestOptions, Response, ResponseOptions, Http } from '@angular/http';
import { MockBackend, MockConnection } from '@angular/http/testing';

import { AccountService } from './../../source/scripts/services/account.service';
import { provide } from '@angular/core';

describe('AccountService', () => {
    // let service;

    beforeEachProviders(() => [
        AccountService,
        BaseRequestOptions,
        MockBackend,
        provide(Http, {
            deps: [MockBackend, BaseRequestOptions],
            useFactory: (backend: MockBackend, defaultOptions: BaseRequestOptions) => {
                return new Http(backend, defaultOptions);
            },
        }),
    ]);

    beforeEach(<any>inject([MockBackend], (backend: MockBackend) => {
        const baseResponse = new Response(new ResponseOptions({ body: 'got response' }));
        backend.connections.subscribe((c: MockConnection) => c.mockRespond(baseResponse));
    }));

    // We use 'done' for async callbacks (http calls)    
    it('should return mocked response', (done) => {

        inject([AccountService], (testService: AccountService) => {
            testService.getUsers().subscribe((res: Response) => {
                expect(res.text()).toBe('got response');
                expect(1).toBe(2);
                done();
            });
        });
    });
});

如何正确地使用模拟后端测试http调用?我怀疑我上面引用的链接已经过时，或者它们没有确认测试实际上在测试，而不是在没有done();异步的情况下仅给出误报.

How do I properly test http calls with a mockbackend? I suspect that either the links I referenced above are out of date or they didn't confirm that the test was actually testing rather than just giving false positives without the async of done();.

推荐答案

您非常亲密.这里仅异步done不适用，因为inject必须替换此匿名回调.所以这是固定版本:

You were very close. Only the async done is not appropriate here because inject has to replace this anonymous callback. So here is the fixed version:

it('should return mocked response', inject([AccountService], (testService: AccountService) => {
  testService.getUsers().subscribe((res: Response) => {
    expect(res.text()).toBe('got response');
    expect(1).toBe(2);
  });
}));

另一个问题缺少beforeEach导入:

import {
    it,
    inject,
    describe,
    beforeEach, // <-- this one was missing
    beforeEachProviders,
    expect,
} from '@angular/core/testing';

因此有一个Jasmine的beforeEach实例，不允许使用inject.

So there was a Jasmine's beforeEach instance which doesn't allow to use inject.

这篇关于使用模拟后端测试HTTP的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！