### auth.service.spec.ts

import { LocalStorageService } from './local-storage.service';
import { HttpModule } from '@angular/http';
import { TestBed } from '@angular/core/testing';

import { AuthService } from './auth.service';

describe( 'AuthService', () => {
  let auth: AuthService;
  const Email = 'test@example.com';
  const Password = 'password';

  beforeEach(() => {
    TestBed.configureTestingModule( {
      imports: [ HttpModule ],
      providers: [ AuthService, LocalStorageService ]
    } );
    auth = TestBed.get( AuthService );
  } );

  it('isAuthenticated() should return true after login', () => {
    auth.login(Email, Password);
    expect(auth.isAuthenticated()).toBeTruthy();
  });
});


### auth.service.ts

@Injectable()
export class AuthService implements OnInit {
  private user = null;
  private token = null;

  isAuthenticated(): boolean {
    return this.token;
  }

  login(email, password) {
    return this.http
    .post(this.BaseURL + this.LoginEndpoint, {
      email: email,
      password: password
    })
    .map(response => {
      const resp = response.json();
      const user = resp.data;
      const token = resp.meta.token;
      this.user = user;
      this.token = token;
      this.storageService.save('token', this.token);
      this.loginNotifier.next();
      return user;
    });
  }