Auth Guard canActivate not working for some reason

Question

When I add AuthGuard service with canActivate on routes, the app crashes when I try to go to /profile and it redirect me to localhost:4200, not even /home and gives this error:

ERROR Error: "[object Object]"

My code :

app.routing.ts

import { NgModule } from '@angular/core';
import { Routes, RouterModule, CanActivate } from '@angular/router';
import { HomeComponent } from './home/home.component';
import { ProfileComponent } from './profile/profile.component';
import { LoginComponent } from './login/login.component';

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

const routes: Routes = [
  {path:'', redirectTo:'/home', pathMatch:'full'},
	{path:'home',component: HomeComponent},
  {path:'login',component: LoginComponent},
  {path:'profile',component: ProfileComponent,canActivate: [AuthGuard]}
];

@NgModule({
  imports: [RouterModule.forRoot(routes)],
  providers: [AuthGuard],
  exports: [RouterModule]
})
export class AppRoutingModule { }

app.module.ts

import { BrowserModule } from '@angular/platform-browser';
import { NgModule } from '@angular/core';

import { AppRoutingModule } from './app-routing.module';
import { AppComponent } from './app.component';
import { HomeComponent } from './home/home.component';
import { LoginComponent } from './login/login.component';
import { ProfileComponent } from './profile/profile.component';
import { TopbarComponent } from './topbar/topbar.component';

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

@NgModule({
  declarations: [
    AppComponent,
    HomeComponent,
    LoginComponent,
    ProfileComponent,
    TopbarComponent
  ],
  imports: [
    BrowserModule,
    AppRoutingModule
  ],
  providers: [AuthGuard, AuthService],
  bootstrap: [AppComponent]
})
export class AppModule { }

auth-guard.servce.ts

import { Injectable } from '@angular/core';
import { Router, CanActivate, ActivatedRouteSnapshot } from '@angular/router';
import { AuthService } from './auth.service';

@Injectable({
  providedIn: 'root'
})
export class AuthGuardService implements CanActivate {

  constructor(public auth: AuthService, public router: Router) { }

  canActivate():boolean{
          if (localStorage.getItem('currentUser')) {
              // logged in so return true
              return true;
          }

          // not logged in so redirect to login page
          this.router.navigate(['/login']);
          return false;
      }
}

It doesn't work!

Answer 1

Had this same issue, solution was to add the Auth Guard to my providers in my app.module.ts

You should also make sure that this is the only file in which it is added to the providers.

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

@NgModule({
  declarations: [
      // whatever your declarations are
  ],
  imports: [
      // Whatever your imports are
  ],
  providers: [
      AuthGuardService
  ],
  bootstrap: [AppComponent]
})
export class AppModule { }