restify-router with group - Typescript - Separated route file

routes.ts

import { Router } from 'restify-router'
import { Request, Response, Next } from 'restify'

const router = new Router()

router.get('/', (req: Request, res: Response, next: Next) => {
  res.send({message: 'home'})
})

router.group('/v1', function (router: Router) {
  router.get('/', (req: Request, res: Response, next: Next) => {
    res.send({message: 'home V1'})
  })

  router.group('/auth', function (router: Router) {
    router.post('/register', (req: Request, res: Response, next: Next) => {
      res.send({message: 'success V1'})
    })
  })
})

export = router

server.ts

import { createServer } from 'restify'
import routes = require('./routes')

const server = createServer()

routes.applyRoutes(server)

server.listen(8081, function () {
  console.log('%s listening at %s', server.name, server.url)
})