AngularJS$httpBackend验证无交互

我正在寻找一种方法来评估

$httpBackend

，看看是否存在任何交互。我想确保在我的测试用例中从未调用过它。我已经检查了这里的文档：$httpBackend，还没有找到答案

使用$http初始化

class HomeService {
  /*@ngInject*/
  constructor ($http, $log) {
    this.http = $http;
    this.log = $log;
  }

  submit(keycode) {
    this.log.log("submitting key code: " + keycode);
    if (keycode === "") {
      return false;
    }
    this.http.post(`/api/keycode/${keycode}`).then ( (response) => {
      this.log.log(response);
      return true;
    });
  }
}

export default HomeService;

到目前为止的测试用例

import HomeService from './home.service';

describe('HomeService', () => {
  let homeService, $httpBackend;

  beforeEach(inject(($injector) => {
    $httpBackend = $injector.get('$httpBackend');
  }));

  afterEach(function() {
   $httpBackend.verifyNoOutstandingExpectation();
   $httpBackend.verifyNoOutstandingRequest();
 });

  describe('submit', () => {

    it('submit empty keycode', () => {
      homeService = new HomeService($httpBackend, console);
      let value = homeService.submit("");
      expect(value).to.be.false;
      //valid no interactions with $httpBackend here!
    });
  });
});

即使

  afterEach(function() {
   $httpBackend.verifyNoOutstandingExpectation();
   $httpBackend.verifyNoOutstandingRequest();
 });

可能足以引发不必要的请求，从而将错误与特定规范使用联系起来：

expect($httpBackend.verifyNoOutstandingExpectation).not.toThrow();

---

HomeService应该注入$http，而不是$httpBackend。