Angular 4.3中的单元测试HttpClientModule:HttpTestingController.expectOne(url)的未定义返回值 [英] Unit testing HttpClientModule in Angular 4.3: undefined return value from HttpTestingController.expectOne(url)

问题描述

我试图了解如何使用新HttpClientModule中提供的模拟功能.我的测试代码几乎完全符合现有文档中显示的内容.但是，该doc示例并不完整-例如，至少缺少TestBad和inject的import语句.我认为@ angular/common/http中的HttpClient也是如此.我的测试代码添加了这些.

I'm trying to understand how to use the mocking functionality provided as part of the new HttpClientModule. My test code matches what's shown in the existing documentation almost exactly. However, the doc example is not complete - for example, at a minimum the import statement for TestBad and inject is missing. I assume the same is true of HttpClient from @angular/common/http. My test code adds these.

此测试失败，因为req在调用httpMock.expectOne之后最终未定义.我很感激为什么会这样.

This test fails, as req ends up being undefined after the httpMock.expectOne call. I'd appreciate any insight into why that might be.

import { TestBed, inject } from '@angular/core/testing';
import { HttpClient } from '@angular/common/http';
import { HttpClientTestingModule, HttpTestingController } from '@angular/common/http/testing';

describe('HttpClientTestingModule', () => {
  beforeEach(() => TestBed.configureTestingModule({
    imports: [ HttpClientTestingModule ],
    providers: [ HttpClient, HttpTestingController]
  }));

  it('expects a GET request', inject([HttpClient, HttpTestingController], (http: HttpClient, httpMock: HttpTestingController) => {
    http
      .get('/data')
      .subscribe(data => expect(data['name']).toEqual('Test Data'));

    const req = httpMock.expectOne('/data');
    expect(req).toBeDefined();
    expect(req.request.method).toEqual('GET');
    req.flush({name: 'Test Data'});
    httpMock.verify();
  }));
});

推荐答案

尽管我不明白为什么会这样，但是通过从TestBed.configureTestingModule中删除以下内容，我可以正常工作:

Though I don't understand why this is the case, I got it working, by removing the following from TestBed.configureTestingModule:

providers: [HttpClient, HttpTestingController]

我欢迎您了解为什么我需要向providers集合中添加我自己的服务，而不是HttpClient, HttpTestingController.

I welcome any insight into why I need to add my own services to providers collection, but not HttpClient, HttpTestingController.

这篇关于Angular 4.3中的单元测试HttpClientModule:HttpTestingController.expectOne(url)的未定义返回值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！