TypeError: guard is not a function

Question

I do not know if I let some detail pass, or if I did something wrong, but I can not find what is causing the error. My goal is to do something that will keep checking if the user is logged in each time he accesses a route within pages.. I use Angular 5.

App.module:

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

import { AppRoutingModule } from './app-routing.module';
import { AppComponent } from './app.component';
import { LoginComponent } from './pages/autenticacao/login.component';
import { AuthService } from './auth/auth.service';
import { RoutesInterceptor } from './auth/routes.interceptor';

import * as $ from 'jquery';

@NgModule({
  declarations: [ AppComponent, LoginComponent ],
  imports: [
    BrowserModule,
    BrowserAnimationsModule,
    AppRoutingModule,

  ],
  bootstrap: [AppComponent],
  providers: [ AuthService, RoutesInterceptor, ],
})
export class AppModule {
}

Routes.intercpetor:

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

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

@Injectable()
export class RoutesInterceptor implements CanActivate {

constructor(private auth: AuthService) {}

canActivate(route: ActivatedRouteSnapshot, state: RouterStateSnapshot): boolean {
    return this.auth.isUserAuthenticated();
}
}

My Routes:

import { NgModule } from '@angular/core';
import { ExtraOptions, RouterModule, Routes } from '@angular/router';

import { LoginComponent } from './pages/autenticacao/login.component';
import { RoutesInterceptor } from './auth/routes.interceptor';

const routes: Routes = [
  { path: 'pages', loadChildren: 'app/pages/pages.module#PagesModule', canActivate: [RoutesInterceptor] },
  { path: 'login', component: LoginComponent },
  { path: '', redirectTo: 'pages', pathMatch: 'full' },
  { path: '**', redirectTo: 'pages' },
];

const config: ExtraOptions = {
  useHash: true,
};

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

Answer 1

Another issue that can cause this is if you try to use a CanActivate guard as another type of guard, like CanActivateChild

Answer 2

I changed that part of the code and it worked

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

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

@Injectable()
export class RoutesInterceptor implements CanActivate {

constructor(private auth: AuthService, private route: Router) {}

  canActivate(route: ActivatedRouteSnapshot, state: RouterStateSnapshot): boolean {
    if (this.auth.isUserAuthenticated()) {
        return true;
    }
    this.route.navigate(['./login']);
    return false;
  }
}

I forgot to redirect if you have not logged in