Angular 2 rc5，服务单元测试问题

Question

@Injectable()
export class Service1 {
    constructor( private s2 : Service2 ) { 
        console.log( s2.name );
     }
}

@Injectable()
export class Service2 {
    public name: string = 'Hi';
}


//------------Test-------------

let service1: MockService1;  // MockService1 extends Service1
let service2: MockService2;  // MockService2 extends Service2

beforeEach(() => {
    TestBed.configureTestingModule({
        providers: [
            { provide: Service1, useClass: MockService1 },
            { provide: Service2, useClass: MockService2 }
        ]
    })
});  

beforeEach(inject( [ Service1 , Service2 ], ( s1: MokcService1 , s2: MockService2  ) => { 
    service1 = s1;
    service2 = s2; 
}));

it('should be defined ', () => {
    expect( service1 ).toBeDefined(); 
    expect( service2 ).toBeDefined();
});

我得到了

TypeError: undefined is not an object (evaluating 's2.name')

因为 Service2 未定义。

相同的代码早先使用了 addProviders 和 provide

beforeEach(() => {
    addProviders([
        provide(Service1, {useClass: MockService1 } ),
        provide(Service2, {useClass: MockService2 } ),
    ]);
});         

删除 console.log( s2.name ) 后，这 2 个测试通过了

有什么想法吗？

Answer 1

在构造函数中注入(inject)服务时使用@Inject，

示例:

constructor( @Inject(Service2) private s2 : Service2 ) { 
    console.log( s2.name );
}