test-server.js

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

const PORT = process.env.PORT ? parseInt(process.env.PORT, 10) : 3001;
const DESIGN_SYSTEM_DIR = __dirname;
const PUBLIC_DIR = path.join(__dirname, '..');

const MIME_TYPES = {
  '.html': 'text/html; charset=utf-8',
  '.css': 'text/css; charset=utf-8',
  '.js': 'application/javascript; charset=utf-8',
  '.json': 'application/json; charset=utf-8',
  '.md': 'text/markdown; charset=utf-8',
  '.svg': 'image/svg+xml',
  '.png': 'image/png',
  '.jpg': 'image/jpeg',
  '.jpeg': 'image/jpeg',
  '.gif': 'image/gif',
  '.ico': 'image/x-icon',
  '.woff': 'font/woff',
  '.woff2': 'font/woff2',
  '.ttf': 'font/ttf',
  '.txt': 'text/plain; charset=utf-8'
};

function isPathInside(child, parent) {
  const relative = path.relative(parent, child);
  return !!relative && !relative.startsWith('..') && !path.isAbsolute(relative);
}

function sendFile(res, filePath, status = 200) {
  const ext = path.extname(filePath).toLowerCase();
  const contentType = MIME_TYPES[ext] || 'application/octet-stream';
  res.writeHead(status, {
    'Content-Type': contentType,
    'Cache-Control': 'no-store'
  });
  const read = fs.createReadStream(filePath);
  read.on('error', () => {
    res.writeHead(500, { 'Content-Type': 'text/plain; charset=utf-8' });
    res.end('Internal Server Error');
  });
  read.pipe(res);
}

const server = http.createServer((req, res) => {
  const urlObj = new URL(req.url, 'http://localhost');
  let pathname = decodeURIComponent(urlObj.pathname || '/');

  // Default to test.html
  if (pathname === '/') {
    pathname = '/test.html';
  }

  // Remove leading slash and resolve path
  const relativePath = pathname.startsWith('/') ? pathname.slice(1) : pathname;
  
  // Resolve file path - check in design-system directory first, then public directory
  let fsPath = path.join(DESIGN_SYSTEM_DIR, relativePath);
  
  // If file doesn't exist in design-system, try public directory
  if (!fs.existsSync(fsPath)) {
    fsPath = path.join(PUBLIC_DIR, relativePath);
  }

  // Prevent directory traversal
  if (!isPathInside(fsPath, DESIGN_SYSTEM_DIR) && !isPathInside(fsPath, PUBLIC_DIR)) {
    res.writeHead(403, { 'Content-Type': 'text/plain; charset=utf-8' });
    res.end('Forbidden');
    return;
  }

  fs.stat(fsPath, (err, stats) => {
    if (err) {
      res.writeHead(404, { 'Content-Type': 'text/plain; charset=utf-8' });
      res.end('Not Found');
      return;
    }
    
    if (stats.isDirectory()) {
      const indexPath = path.join(fsPath, 'index.html');
      if (fs.existsSync(indexPath)) {
        sendFile(res, indexPath, 200);
      } else {
        res.writeHead(403, { 'Content-Type': 'text/plain; charset=utf-8' });
        res.end('Forbidden');
      }
      return;
    }
    
    sendFile(res, fsPath, 200);
  });
});

server.listen(PORT, () => {
  console.log(`Design System Test Server running at http://localhost:${PORT}`);
  console.log(`Open http://localhost:${PORT} in your browser`);
});