import Koa from 'koa'
import router from '@tadashi/koa-router'

const fakeAuth = (ctx, next) => {
  ctx.state.auth = true
  return next()
}

const productMiddleware = ctx => {
  ctx.body = {
    auth: ctx.state.auth,
    id: ctx.params.id
  }
}

const app = new Koa()
app
  .use(router.get('/product/:id', fakeAuth, productMiddleware))
  .use(router.all('/', ctx => {
    ctx.body = 'nothing to see here!'
  }))

//...