fmode-app/prototypes/fmode-mvp-20261014/server.mjs

import { createServer } from 'node:http';
import { readFile } from 'node:fs/promises';
import { dirname, extname, resolve, sep } from 'node:path';
import { fileURLToPath } from 'node:url';

const root = dirname(fileURLToPath(import.meta.url));
const port = Number(process.env.DEMO_PORT || 4300);
const types = { '.html': 'text/html; charset=utf-8', '.css': 'text/css; charset=utf-8', '.js': 'text/javascript; charset=utf-8', '.md': 'text/plain; charset=utf-8', '.json': 'application/json' };
createServer(async (request, response) => {
  try {
    const url = new URL(request.url, `http://localhost:${port}`);
    const pathname = decodeURIComponent(url.pathname);
    const path = resolve(root, '.' + pathname);
    if (path !== root && !path.startsWith(root + sep)) {
      response.writeHead(403); response.end('Forbidden'); return;
    }
    const isRoute = !extname(pathname) || pathname === '/';
    const data = await readFile(isRoute ? resolve(root, 'index.html') : path);
    response.writeHead(200, {
      'Content-Type': isRoute ? types['.html'] : types[extname(path)] || 'application/octet-stream',
      'Cache-Control': 'no-store',
      'X-Content-Type-Options': 'nosniff',
      'Referrer-Policy': 'no-referrer',
    });
    response.end(data);
  } catch {
    response.writeHead(404); response.end('Not found');
  }
}).listen(port, '0.0.0.0', () => {
  process.stdout.write(`Fmode design demo: http://localhost:${port}\n`);
});