koa.js

const Koa = require('koa');
const Router = require('koa-router');

const app = new Koa();
const router = new Router();

let users = [
  {
    name: "Jacob",
    email: "[email protected]",
  },
  {
    name: "Kenny",
    email: "[email protected]",
  },
  {
    name: "Joe",
    email: "[email protected]",
  },
];

//localhost:3000
router.get('/user/:id', ctx => {
  ctx.body = users[ctx.params.id];
});

router.post('/user/:id', ctx => {
  ctx.body = Object.assign(users[ctx.params.id], ctx.request.body);
});

app.use(require('koa-body')());
app.use(router.allowedMethods());
app.use(router.routes());

app.listen('3000');