import { Component , OnInit } from '@angular/core' ; import { AngularFireAuth } from '@angular/fire/auth' ; import { from , Observable } from 'rxjs' ; import { concatMap , filter , map } from 'rxjs/operators' ; import { AngularFirestore } from '@angular/fire/firestore' ; import { Router } from '@angular/router' ; import { UserService } from "./services/user.service" ; import { AuthTokenService } from "./services/auth-token.service" ; @ Component ( { selector : 'app-root' , templateUrl : './app.component.html' , styleUrls : [ './app.component.css' ] } ) export class AppComponent implements OnInit { constructor ( public user , private token ) { } ngOnInit ( ) { } logout ( ) { this . user . logout ( ) ; } }