Angular 2 RC-5 异步测试不工作

Question

那是代码：

import {
  async,
  inject,
  TestBed
} from '@angular/core/testing';
import {
  Http,
  Response,
  ResponseOptions,
  RequestOptions,
  BaseRequestOptions,
  ConnectionBackend
} from "@angular/http";
import {MockBackend, MockConnection} from "@angular/http/testing";
import {HttpInterceptor, RequestWrapped} from "./http.interceptor.service.ts";

describe("Http interceptor", () => {
  beforeEach(() =>{
    TestBed.configureTestingModule({
      providers: [
        MockBackend,
        BaseRequestOptions,
        {provide: ConnectionBackend, useClass: MockBackend},
        {provide: RequestOptions, useClass: BaseRequestOptions},
        Http
      ],
    });
  });

  it('should get blogs', inject([Http, MockBackend], (http:Http, backend:MockBackend) => {
    let connection:MockConnection;
    backend.connections.subscribe(connection =>
      connection.mockRespond(new Response(new ResponseOptions('awesome')))
    );
    http.request('data.json').subscribe((res) => {
      expect(res.text()).toBe('awesome2');
    });
  }));
});

这个测试应该会失败，很明显 awesome 不等于 awesome2，为什么不起作用？

Answer 1

因为it方法在异步回调之前执行完毕。在 vanilla Jasmine 中，您将使用 done

处理异步

it('', function (done) {
  setTimeout(function () {
    expect(2).toBe(2);
    done();
  }, 1000);
});

done 是 Jasmine 知道我们已完成所有异步事件并且测试已完成的方式。

使用 Angular，而不是显式调用 done，我们应该在 async 中调用 fundtion。这会将整个方法包装在一个区域中，并在其中跟踪所有异步调用。当所有异步调用都完成后，测试就完成了。这不同于同步测试，后者一旦方法完成，测试就完成了

import { async } from '@angular/core/testing';                

                    // async wapper
it('should get blogs', async(inject([Http, MockBackend], (http:Http, backend:MockBackend) => {
  let connection:MockConnection;
  backend.connections.subscribe(connection =>
    connection.mockRespond(new Response(new ResponseOptions('awesome')))
  );
  http.request('data.json').subscribe((res) => {
    expect(res.text()).toBe('awesome2');
  });
})));

还有fakeAsync，可以让你控制"ticks"

it('should get blogs', fakeAsync(inject([Http, MockBackend], (http:Http, backend:MockBackend) => {
  let connection:MockConnection;
  backend.connections.subscribe(connection =>
    connection.mockRespond(new Response(new ResponseOptions('awesome')))
  );
  let text;
  http.request('data.json').subscribe((res) => {
    text = res.text();
  });
  tick();
  expect(res.text()).toBe('awesome2');
})));

Angular 2 RC-5 异步测试不工作

Angular 2 RC-5 Async testing is not working

angular

angular2-testing