serve.js

import http from 'http';
import fs from 'fs';
import path from 'path';

const port = process.env.PORT || 3000;
const root = process.cwd();

const contentType = (filePath) => {
  if (filePath.endsWith('.html')) return 'text/html';
  if (filePath.endsWith('.js')) return 'application/javascript';
  if (filePath.endsWith('.css')) return 'text/css';
  if (filePath.endsWith('.json')) return 'application/json';
  return 'text/plain';
};

const server = http.createServer((req, res) => {
  let reqPath = decodeURI(req.url.split('?')[0]);
  if (reqPath === '/') reqPath = '/index.html';
  const filePath = path.join(root, reqPath);

  fs.stat(filePath, (err, stats) => {
    if (err) {
      res.writeHead(404, { 'Content-Type': 'text/plain' });
      res.end('Not found');
      return;
    }

    if (stats.isDirectory()) {
      res.writeHead(200, { 'Content-Type': 'text/html' });
      const files = fs.readdirSync(filePath).map(f => `<li><a href="${path.join(reqPath, f)}">${f}</a></li>`).join('\n');
      res.end(`<h1>Index of ${reqPath}</h1><ul>${files}</ul>`);
      return;
    }

    fs.createReadStream(filePath).pipe(res);
    res.writeHead(200, { 'Content-Type': contentType(filePath) });
  });
});

server.listen(port, () => {
  console.log(`Serving ${root} at http://localhost:${port}`);
});