doneit-web/src/app/guards/auth.guard.ts

import { Injectable } from '@angular/core';
import { CanActivate, ActivatedRouteSnapshot, RouterStateSnapshot, UrlTree, Router } from '@angular/router';
import { Observable } from 'rxjs';

@Injectable({
  providedIn: 'root'
})
export class AuthGuard implements CanActivate {
  constructor(
    private router:Router
  ){}
  
  canActivate(
    route: ActivatedRouteSnapshot,
    state: RouterStateSnapshot): Observable<boolean | UrlTree> | Promise<boolean | UrlTree> | boolean | UrlTree {
    
    if(window.location.pathname != '' && !localStorage.getItem('UserData')) {
      this.router.navigate(['/']);
      return false
    } else {
      return true
    }
  }
  
}