koa环境搭建
安装node.js
brew install node
创建项目，项目名叫dudu
mkdir dudu
cd dudu
npm init
添加koa模块
npm install -save koa
编写index.js
const Koa = require('koa')
const app = new Koa()
app.use( async ( ctx ) => {
ctx.body = 'hello koa2'
})
app.listen(3000)
console.log('start-quick is starting at port 3000')
运行
npm start // node index.js
TypeScript
安装TypeScript
npm install -g typescript ts-node nodemon
npm install -D @types/node @types/koa
生成tsconfig.json
tsc --init
监视代码变更
"scripts": {
"dev": "tsc -w | nodemon ."
},
更新代码 src/application.ts
import Koa, { Context } from 'koa';
import { Server } from 'http';
export class Application {
private app: Koa;
constructor() {
this.app = new Koa();
const server = async (ctx: Context, next: any ) => {
if(ctx.url == "/")
{
ctx.body = "Running..."
}
if(ctx.url === '/test')
{
ctx.body = {info:'this is test message.'}
}
next && next()
}
this.app.use(server)
}
public run(port: number) : Server {
console.log('start-quick is starting at port 3000')
return this.app.listen(port)
}
}
运行
npm run dev