const Koa = require('koa')
const route = require('koa-route')
const app = new Koa()

app.use(async function middleware1(ctx, next) {
  console.log('middleware1 開始')
  await next()
  console.log('middleware1 結(jié)束')
})

app.use(async function middleware2(ctx, next) {
  const p = new Promise((resolve, reject) => {
    resolve('middleware2 開始')
  })
  p.then(res => {
    console.log(res)
  })
  await next()
  console.log('middleware2 結(jié)束')
})

app.use(async function middleware3(ctx, next) {
  console.log('middleware3 開始')
  await next()
  console.log('middleware3 結(jié)束')
})

app.use(route.get('/', (ctx, next) => {
  ctx.body = 'hello koa'
}))

app.listen(3001, function () {
  console.log('server is listening on port 3001')
})

// middleware1 開始
// middleware3 開始
// middleware2 開始
// middleware3 結(jié)束
// middleware2 結(jié)束
// middleware1 結(jié)束

const express = require('express')
const app = express()

app.use(function middleware1(req, res, next) {
  console.log('middleware1 開始')
  next()
  console.log('middleware1 結(jié)束')
})

app.use(function middleware2(req, res, next) {
  const p = new Promise((resolve, reject) => {
    resolve('middleware2 開始')
  })
  p.then(res => {
    console.log(res)
  })
  next()
  console.log('middleware2 結(jié)束')
})

app.use(function middleware3(req, res, next) {
  console.log('middleware3 開始')
  next()
  console.log('middleware3 結(jié)束')
})

app.get('/', function (req, res, next) {
  res.end('hello express')
})

app.listen(3000, function () {
  console.log('server listening on port 3000!')
})

// middleware1 開始
// middleware3 開始
// middleware3 結(jié)束
// middleware2 結(jié)束
// middleware1 結(jié)束
// middleware2 開始