Angular2 RC4单元测试服务

Question

服务

@Injectable()

export class NavService {

    constructor (
        public pagesToLoad
    ) {
        this.pagesToLoad = [1,2,3,4,5]
    }

    public lookAround(currentPage){
        let tuple = (this.pagesToLoad.indexOf(currentPage)-1,this.pagesToLoad.indexOf(currentPage)+1)
        return tuple
    }

测试

import {Modal, Alert, NavParams, ViewController, Events} from 'ionic-angular';
import {provide,ReflectiveInjector,Component,PLATFORM_PIPES} from '@angular/core'
import { HTTP_PROVIDERS, XHRBackend, Http } from '@angular/http';
import { MockBackend } from '@angular/http/testing';
import { getDOM } from '@angular/platform-browser/src/dom/dom_adapter';
import {
  TEST_BROWSER_DYNAMIC_PLATFORM_PROVIDERS, TEST_BROWSER_DYNAMIC_APPLICATION_PROVIDERS
}  from '@angular/platform-browser-dynamic/testing';
import {
  beforeEach,
  beforeEachProviders,
  describe,
  expect,
  it,
  xit, 
  xdescribe,
  ComponentFixture, 
  inject,
  async,
  setBaseTestProviders,
  TestComponentBuilder
} from '@angular/core/testing'
 import {NavService} from './nav-service';

let tcb;
let navService;

beforeEachProviders(() => [
    provide(navService, {useClass: NavService})
]);

beforeEach(inject(
        [
            TestComponentBuilder,
            NavService
        ], 
        (
            _tcb,
            _navService
        ) => { 
            tcb         = _tcb
            navService  = _navService

    }));

describe('NavService', () => {

    it ('should have instantiated nav service', () => {
        expect(this.navService instanceof NavService).toBeTruthy()
     })
})

错误

TypeError: Cannot read property 'lookAround' of undefined

应该很直接，但我的测试失败了。怎么了？

Answer 1

当然，直接测试服务时我不必提供依赖项。所以这就像这样：

import {NavService} from './nav-service'

describe('NavService', () => {

    it ('should have instantiated nav service', () => {
        let navService = new NavService();
        expect(navService.lookAround(3)).toEqual((2,4))
     })
})

  

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