Angular 因果报应错误：没有提供'；ServiceName'；！

我正在为我的AccountLogin服务编写UTC。在其构造函数中，它根据环境获取实例。若环境为true，则获取AccountLoginMockService的实例，否则获取AccountLoginApiService。因为我已经将env设置为true，所以它总是获取AccountLoginMockService的实例

import { Injectable, Injector, EventEmitter } from '@angular/core'
import { environment } from '../../../../environments/environment';
import { Observable } from 'rxjs/Observable';
import { AccountLoginMockService } from './accountLogin.service.mock';
import { AccountLoginApiService } from './accountLogin.service.api';
import { AccountLogin } from '../accountLogin';
import { CacheCustomService } from '../../../shared/services/cache/cacheCustom.service';
import { UserDetail } from './accountLogin.model';
import { InstanceService } from '../../../shared/services/instance.service';

export interface IAccountLoginService {
    singinUser(userDetails: AccountLogin): Observable<UserDetail>,
    logout(): void,
    isAuthorized(): boolean,
};

@Injectable()
export class AccountLoginService implements IAccountLoginService {

    loginService: IAccountLoginService;
    cacheService: CacheCustomService;
    loginStatusEmitter: EventEmitter<UserDetail> = new EventEmitter<UserDetail>();


    /**
     * Constructor
     * @param  {InstanceService} privateinstanceService
     */
    constructor(private instanceService: InstanceService) {
        this.loginService = this.instanceService.getInstance((environment.needMock) ?
            AccountLoginMockService : AccountLoginApiService);

        this.cacheService = this.instanceService.getInstance(CacheCustomService);
    };

      ;

    /**
     * Calls signin function of concerned service
     * @param  {} userDetails
     * @returns Observable
     */
    singinUser(userDetails: AccountLogin): Observable<UserDetail> {
        return this.loginService.singinUser(userDetails).map((data) => {
            this.storeUserDetail(data);
            return data;
        });
    };

    /**
     * Calls logout function of concerned service
     * @returns void
     */
    logout(): void {
        this.cacheService.deleteCacheKey('userDetail');
        return this.loginService.logout();
    };

    /**
     * calls isAuthorized function of concerned service
     * @returns boolean
     */
    isAuthorized(): boolean {
        return this.loginService.isAuthorized();
    };

    /**
     * Stores user details in cache and emits to login status component
     * @param  {UserDetail} userDetail
     */
    private storeUserDetail(userDetail: UserDetail) {
        this.cacheService.storeDataToCache(userDetail, 'userDetail', false)
        this.loginStatusEmitter.emit(userDetail);
    }

};

import { AccountLoginService } from './accountLogin.service'
import { ReflectiveInjector, EventEmitter } from "@angular/core";
import { InstanceService } from "app/shared/services/instance.service";
import { TestBed } from "@angular/core/testing";
import { AccountLoginApiService, AccountLoginMockService } from "app/pages/accountLogin/accountLoginService";
import { CacheCustomService } from "app/shared/services/cache/cacheCustom.service";
import { AccountLoginModule } from "app/pages/accountLogin/accountLogin.module";
import { Observable } from "rxjs/Observable"; 
import { HttpModule } from "@angular/http";


describe('Account Login Service', () => {


    let accountLoginService : AccountLoginService,
    mockCacheService: CacheCustomService , 
    mockInstanceService :InstanceService,
    mockAccountLoginApiService ={};


    beforeEach(async() =>{

    let mockAccountLoginService = { 

        singinUser :(userDetails)=>{
            if(userDetails.userName === 'abc@123.com' && userDetails.password === '123456'){
                return Observable.of(true);
            } else {
                return Observable.of(false);
            }
        }

    }

        TestBed.configureTestingModule({

        providers : [
             { provide: AccountLoginMockService, useValue: mockAccountLoginService },
             //{ provide: AccountLoginApiService, useValue: mockAccountLoginApiService },
             InstanceService, AccountLoginApiService, AccountLoginMockService , AccountLoginApiService]
    });
    })

    beforeEach(() => {
        const injector = ReflectiveInjector.resolveAndCreate([InstanceService])
        mockInstanceService = injector.get(InstanceService);

        accountLoginService =  new AccountLoginService(mockInstanceService);
    })


    it('should be able to login' ,()=>{
        let userDetails = { userName:'intershop@123.com', password: '123456'}
        accountLoginService.singinUser(userDetails).subscribe( (data)=>{
            console.log(data);
            expect(data).toBeDefined;
        })
    });

});