Question

我创建了这个测试：

import { ComponentFixture, TestBed } from '@angular/core/testing';
import { By }              from '@angular/platform-browser';
import { DebugElement }    from '@angular/core';

import { GamePanelComponent } from './gamepanel.component';

describe('GamePanelComponent (inline template)', () => {

  let comp:    GamePanelComponent;
  let fixture: ComponentFixture<GamePanelComponent>;  

  beforeEach(() => {

    TestBed.configureTestingModule({
      declarations: [ GamePanelComponent ], // declare the test component
    }).compileComponents()
        .then(() => {
            fixture = TestBed.createComponent(GamePanelComponent);            
            comp = fixture.componentInstance;
        });
  });

  it('isValidMove', () => {      
      comp.ngOnInit();
      comp.game.board[0][0] = 'X';
      let isValid = comp.isValidMove(0,0);
      expect(isValid).toBe(false);
  });

});

奇怪的是测试失败了，因为TypeError: Cannot read property 'ngOnInit' of undefined错误。

显然，comp甚至fixture未定义。如您所见，我使用beforeEach方法初始化它们：

fixture = TestBed.createComponent(GamePanelComponent);            
comp = fixture.componentInstance;

我的代码中出现了什么问题？

Answer 1

你是异步创建组件但是你没有等待它准备就绪，为了做到这一点，你应该使用异步。

这是一个更好的例子：

let comp;
let fixture;
 beforeEach( async( () => {
   TestBed.configureTestingModule( {
        imports : [  ],
        declarations : [
            GamePanelComponent
        ],
        providers : [
        ]
    } );
    TestBed.compileComponents();

     fixture=TestBed.createComponent( TestComponent );
     comp = fixture.componentInstance;
        fixture.detectChanges();

  } ) );

it( 'should create my component ', () => {

      expect(comp.ngOnInit).toBeDefined()

} );

Angular2 - jasmine在初始化后无法识别对象

1 个答案: