狼叔（卷二 ） node.js web应用开发 读书笔记

npm init -y
npm i -S koa@2

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

app.use(async (ctx,next) => {
    const start = new Date()
    console.log('[logger middleware] before await ...')
    await next()
    console.log('[logger middleware] after await ...')
    const ms = new Date() - start
    console.log(`${ctx.method} ${ctx.url} - ${ms}ms`)
})

app.use(async ctx =>{
    console.log('[response middleware] response ...')
    ctx.body = 'Hello Koa 2'
})

app.listen(3000)

var koa = requier('koa');
var app = koa();

const Koa = require('koa');
const app = new Koa();

npm i --global koa-generator

koa2 helloworld