Question

我正在使用Karma-Jasmines为您的Web应用程序编写单元测试Angular 5。我使用Injector注入服务。

创建InjectableObject方法：

import { Injector } from '@angular/core';
let appInjectorRef: Injector;
export const InjectableObject = (injector?: Injector): Injector => {
   if (injector) {
      appInjectorRef = injector;
  }
  return appInjectorRef;
};

创建BaseComponent类：

import { InjectableObject } from './injectableobject.base';
import { MyDataService} from '../services/mydata.service';

interface IBaseComponentOptions {
    hotkey?: boolean;
    tableName?: string
}

export class BaseComponent implements OnInit, OnDestroy, AfterContentInit{
    constructor(private opt?: IBaseComponentOptions) {
       const _injector = InjectableObject();

       this._myDataService = _injector.get(MyDataService);
    }
}

创建一个从BaseComponent扩展的组件：

@Component({
    selector: 'app-header',
    templateUrl: './header.component.html',
    styleUrls: ['./header.component.scss']
})
export class HeaderComponent extends BaseComponent implements OnInit {
    constructor(
        private dataService: MyDataService,
    ){super()}
}

创建文件单元测试：从“”导入{MessageService}; 从''导入{HeaderComponent};

describe('HeaderComponent', () => {
   let component: HeaderComponent;
   let fixture: ComponentFixture<HeaderComponent>;
   let backend: MockBackend;
   beforeEach(async(() => {
      TestBed.configureTestingModule({
          declarations: [HeaderComponent],
          provides: [MyDataService]
      })
   }).compileComponents();

   beforeEach(() => {
      fixture = TestBed.createComponent(HeaderComponent);
      component = fixture.componentInstance;
      fixture.detectChanges();
   });

   it('should create', () => {
       expect(component).toBeTruthy();
   });
});

但是当我进行测试时，我已经得到了：

TypeError：无法读取未定义的属性“ get”

，位于“ this._myDataService = _injector.get（MyDataService）;”处在BaseComponent中。

我不知道写单元测试可以通过这种情况。请大家帮我！谢谢大家！

Answer 1

它与异步调用有关.....

用fakeAsync调用包装该测试用例。...

it('should create', () => {
    fakeAsync(() => {
        expect(component).toBeTruthy();
    });
});

然后从@angular/core/testing导入

Angular 5单元测试：“无法读取Injector中未定义的属性'get'”

1 个答案: