add auth guard

import { TestBed } from '@angular/core/testing';

import { AuthGuard } from './auth-guard.service';

describe('AuthGuardService', () => {

  beforeEach(() => TestBed.configureTestingModule({}));

  it('should be created', () => {

    const service: AuthGuard = TestBed.get(AuthGuard);

    expect(service).toBeTruthy();

  });

});

import {ActivatedRouteSnapshot, CanActivate, Router, RouterStateSnapshot} from '@angular/router';

import {Observable} from 'rxjs/Observable';

import {Injectable} from '@angular/core';

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

@Injectable()

export class AuthGuard implements CanActivate {

  constructor(private authService: AuthService, private router: Router) {}

  canActivate(route: ActivatedRouteSnapshot,

              state: RouterStateSnapshot): Observable<boolean> | Promise<boolean> | boolean {

     return this.authService.isAuthenticated()

      .then(

        (authenticated: boolean) => {

          if (authenticated) {

            return true;

          } else {

            this.router.navigate(['/login']);

          }

        }

      );

  }

}

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