Can'；不要让angular2业力测试发挥作用

我有这个代码，但我不能让它通过测试

/**
* Created by vu.kim.long on 09.02.2017.
*/
import {Component} from '@angular/core';
import {Http, ConnectionBackend, BaseRequestOptions, ResponseOptions, Response} from "@angular/http";
import {MockBackend} from "@angular/http/testing";
import {TestBed, inject, fakeAsync, tick, async} from "@angular/core/testing";
import {GroupFormService} from "./group-form.service";
import {GroupFormModule} from "./group-form.module";

export function main() {
describe('GroupForm Service', () => {

beforeEach(() => {

  TestBed.configureTestingModule({
    providers: [{
      provide: Http,
      useFactory: (backend: ConnectionBackend, defaultOptions: BaseRequestOptions) => {
        return new Http(backend, defaultOptions);
      }, deps: [MockBackend, BaseRequestOptions]
    },
      GroupFormService,
      MockBackend,
      BaseRequestOptions
    ]
  });
});

it("get avaible supervisors",
  inject([GroupFormService, MockBackend], async((groupFormService: GroupFormService, mockBackend: MockBackend) => {
    let response: string;

    groupFormService.setURL("supervisors");
    mockBackend.connections.subscribe(c => {
      expect(c.request.url).toBe("http://34.249.136.226/bm-rest-api/api/static/supervisors");
      c.mockRespond(new Response(new ResponseOptions({
          body: JSON.stringify(
            {
              id: 1,
              firstname: "Jostein",
              lastname: "Guldal",
              enterpriseid: "jostein.guldal",
              tags: "supervisor"
            }
          )
        }
      )));
    });

    groupFormService.get().subscribe(res => {
      expect(res.json()).toEqual(
        {
          id: 1,
          firstname: "Jostein",
          lastname: "Guldal",
          enterpriseid: "jostein.guldal",
          tags: "supervisor"
        })
    });

  })));
  });
  }

模拟数据的名字是Jostein，我将其与Jostein进行比较。为什么我会得到：

FAILED TESTS:
 GroupForm Service
  × get avaible supervisors
  Chrome 56.0.2924 (Windows 10 0.0.0)
 TypeError: done.fail is not a function
    at eval (node_modules/@angular/core/bundles/core-testing.umd.js:53:30)
    at eval (node_modules/@angular/core/bundles/core-testing.umd.js:100:21)

我有一个服务返回一个主管列表，但在这个测试中，我只是返回一个主管。我考试做错了吗

我将此作为一个来源：