Spinner no carregamento de uma rota no Angular 2+

angular-router-spinner.ts

import { Component } from '@angular/core';
import { Router, NavigationStart, NavigationEnd } from '@angular/router';

@Component({
  selector: 'app-root',
  templateUrl: './app.component.html',
  styleUrls: ['../assets/styles/index.sass'],
})
export class AppComponent {
  constructor(
    private router: Router,
  ) {
    this.router.events.subscribe(event => {
      if (event instanceof NavigationStart) {
        console.log('iniciar spinner');
      }
      if (event instanceof NavigationEnd) {
        console.log('finalizar spinner');
      }
    });
  }
}