feat: First iteration, multi themes, I18N

server/static.js

@@ -0,0 +1,71 @@
+import { createReadStream } from 'node:fs';
+import { stat } from 'node:fs/promises';
+import path from 'node:path';
+
+const MIME = {
+  '.html': 'text/html; charset=utf-8',
+  '.css': 'text/css; charset=utf-8',
+  '.js': 'text/javascript; charset=utf-8',
+  '.json': 'application/json; charset=utf-8',
+  '.svg': 'image/svg+xml',
+  '.png': 'image/png',
+  '.jpg': 'image/jpeg',
+  '.webp': 'image/webp',
+  '.ico': 'image/x-icon',
+  '.woff2': 'font/woff2',
+  '.txt': 'text/plain; charset=utf-8',
+};
+
+/**
+ * Resolve a URL pathname to a file inside `root`, or null if it escapes it.
+ * Exported for tests.
+ */
+export function resolveSafe(root, pathname) {
+  let decoded;
+  try {
+    decoded = decodeURIComponent(pathname);
+  } catch {
+    return null;
+  }
+  if (decoded.includes('\0')) return null;
+  const target = path.resolve(root, '.' + path.posix.normalize('/' + decoded));
+  return target === root || target.startsWith(root + path.sep) ? target : null;
+}
+
+/** Serve files from `root`. Revalidates with ETag so edits show up on refresh. */
+export function createStaticHandler(root) {
+  const base = path.resolve(root);
+
+  return async function serve(req, res, pathname, headers) {
+    let file = resolveSafe(base, pathname === '/' ? '/index.html' : pathname);
+    if (!file) return send(res, 400, headers, 'Bad request');
+
+    let info;
+    try {
+      info = await stat(file);
+      if (info.isDirectory()) {
+        file = path.join(file, 'index.html');
+        info = await stat(file);
+      }
+    } catch {
+      return send(res, 404, headers, 'Not found');
+    }
+
+    const etag = `W/"${info.size.toString(16)}-${Math.floor(info.mtimeMs).toString(16)}"`;
+    const type = MIME[path.extname(file).toLowerCase()] ?? 'application/octet-stream';
+    const out = { ...headers, 'Content-Type': type, 'Cache-Control': 'no-cache', ETag: etag };
+
+    if (req.headers['if-none-match'] === etag) {
+      res.writeHead(304, out);
+      return res.end();
+    }
+    res.writeHead(200, { ...out, 'Content-Length': info.size });
+    if (req.method === 'HEAD') return res.end();
+    createReadStream(file).on('error', () => res.destroy()).pipe(res);
+  };
+}
+
+function send(res, status, headers, text) {
+  res.writeHead(status, { ...headers, 'Content-Type': 'text/plain; charset=utf-8' });
+  res.end(text);
+}