// routes/atricle.js
const article = (() => {
  const router = express.Router()

  router.get('/foo', (req, res, next) => {
    res.end('atricle foo')
  })

  router.get('/bar', (req, res, next) => {
    res.end('atricle bar')
  })

  return router
})()

// routes/user.js
const user = (() => {
  const router = express.Router()

  router.get('/foo', (req, res, next) => {
    res.end('user foo')
  })

  router.get('/bar', (req, res, next) => {
    res.end('user bar')
  })

  return router
})()

app.use('/article', article)
app.use('/user', user)