server.js

const http = require('http')
const url = require('url')
const fs = require('fs')
const path = require('path')
const port = process.argv[2] || 9000

http.createServer(function (req, res) {
    console.log(`${req.method} ${req.url}`)

    // parse URL
    const parsedUrl = url.parse(req.url)
    // extract URL path
    let pathname = decodeURI(`.${parsedUrl.pathname}`)
    // based on the URL path, extract the file extention. e.g. .js, .doc, ...
    const ext = path.parse(pathname).ext || '.html'
    // maps file extention to MIME typere
    const map = {
        '.ico': 'image/x-icon',
        '.html': 'text/html',
        '.js': 'text/javascript',
        '.json': 'application/json',
        '.css': 'text/css',
        '.png': 'image/png',
        '.jpg': 'image/jpeg',
        '.wav': 'audio/wav',
        '.mp3': 'audio/mpeg',
        '.svg': 'image/svg+xml',
        '.pdf': 'application/pdf',
        '.doc': 'application/msword',
        '.kml': 'application/vnd.google-earth.kml+xml',
    }

    fs.exists(pathname, function (exist) {
        if (!exist) {
            // if the file is not found, return 404
            res.statusCode = 404
            res.end(`File ${pathname} not found!`)
            return
        }

        // if is a directory search for index file matching the extention
        if (fs.statSync(pathname).isDirectory()) {
            pathname += '/index' + ext
        }

        // read file from file system
        fs.readFile(pathname, function (err, data) {
            if (err) {
                res.statusCode = 500
                res.end(`Error getting the file: ${err}.`)
            } else {
                // if the file is found, set Content-type and send data
                res.setHeader('Content-type', map[ext] || 'text/plain')
                res.setHeader('Service-Worker-Allowed', '/')
                res.end(data)
            }
        })
    })
}).listen(parseInt(port))

console.log(`Server listening on port ${port}`)