app-routing.module.ts

const lazyPathValue = 'lazy';
export const LAZY_PATH = new InjectionToken('LAZY_PATH');

@NgModule({
  imports: [
    RouterModule.forRoot(
      [
        {
          path: '',
          pathMatch: 'full',
          redirectTo: lazyPathValue
        },
        {
          path: lazyPathValue,
          loadChildren: './lazy/lazy.module#LazyModule',
        }
      ]
    )
  ],
  providers: [{ provide: LAZY_PATH, useValue: lazyPathValue }],
  exports: [RouterModule]
})
export class AppRoutingModule { }