serve.mjs

#!/usr/bin/env node
/**
 * Minimal static file server for local previews.
 *   npm run serve   →   http://localhost:8080
 *
 * Resolves "/blog/" style directory URLs to their index.html so the site
 * behaves the same way GitHub Pages does.
 */

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

const ROOT = join(dirname(fileURLToPath(import.meta.url)), '..');
const PORT = process.env.PORT || 8080;

const TYPES = {
  '.html': 'text/html; charset=utf-8',
  '.css': 'text/css; charset=utf-8',
  '.js': 'text/javascript; charset=utf-8',
  '.xml': 'application/xml; charset=utf-8',
  '.png': 'image/png',
  '.jpg': 'image/jpeg',
  '.svg': 'image/svg+xml',
  '.ico': 'image/x-icon',
};

createServer(async (req, res) => {
  try {
    let urlPath = decodeURIComponent(new URL(req.url, `http://localhost`).pathname);
    let filePath = normalize(join(ROOT, urlPath));
    if (!filePath.startsWith(ROOT)) {
      res.writeHead(403).end('Forbidden');
      return;
    }
    let info = await stat(filePath).catch(() => null);
    if (info && info.isDirectory()) {
      filePath = join(filePath, 'index.html');
      info = await stat(filePath).catch(() => null);
    }
    if (!info) {
      res.writeHead(404, { 'Content-Type': 'text/html' }).end('<h1>404</h1>');
      return;
    }
    const body = await readFile(filePath);
    res.writeHead(200, { 'Content-Type': TYPES[extname(filePath)] || 'application/octet-stream' });
    res.end(body);
  } catch (err) {
    res.writeHead(500).end('Server error');
  }
}).listen(PORT, () => {
  console.log(`Serving ${ROOT}\n  → http://localhost:${PORT}/\n  → http://localhost:${PORT}/blog/`);
});