http-server-serving-files.js

const http = require('http')
const fs = require('fs')
const path = require('path')

const extensionToContentType = {
  '.js': 'application/javascript',
  '.html': 'text/html'
}

http.createServer((req, res) => {
  if (req.url.startsWith('/public')) {
    const file = path.join('public', req.url.substring('/static'.length))

    res.setHeader('Content-Type', extensionToContentType[path.extname(file)])

    fs.createReadStream(file).pipe(res)
  }
  else {
    res.statusCode = 404
    res.end()
  }
}).listen(process.env.PORT || 3000, () => console.log('listening...'))