Fable clean up

scripts/lib/dist.mjs

@@ -0,0 +1,108 @@
+import { createServer } from 'node:http';
+import { readFile, stat } from 'node:fs/promises';
+import path from 'node:path';
+import { walk } from './walk.mjs';
+
+export const dist = path.resolve('dist');
+
+const INDEX_FILE = 'index.html';
+
+export async function requireDist() {
+  try {
+    await stat(dist);
+  } catch {
+    throw new Error('dist/ does not exist. Run npm run build first.');
+  }
+}
+
+// Derives the site's route list from the HTML files in dist/.
+export async function discoverRoutes() {
+  const files = await walk(dist);
+  const routes = new Set();
+
+  for (const file of files) {
+    if (!file.endsWith('.html')) continue;
+    const rel = path.relative(dist, file).replaceAll(path.sep, '/');
+    if (rel === '404.html') continue;
+    if (rel === INDEX_FILE) {
+      routes.add('/');
+    } else if (rel.endsWith(`/${INDEX_FILE}`)) {
+      routes.add('/' + rel.slice(0, -INDEX_FILE.length));
+    } else {
+      routes.add('/' + rel.replace(/\.html$/, '/'));
+    }
+  }
+
+  return [...routes].sort();
+}
+
+// Maps a request URL (or pathname) to a file in dist/, mirroring static-host
+// semantics: the path itself, its directory index.html, or the extensionless
+// .html variant. Returns null when nothing matches.
+export async function resolveFile(url) {
+  const parsed = new URL(url, 'http://localhost');
+  const safePath = path
+    .normalize(decodeURIComponent(parsed.pathname))
+    .replace(/^\/+/, '')
+    .replace(/^(\.\.(\/|\\|$))+/, '');
+  const candidate = path.join(dist, safePath);
+  const candidates = [
+    candidate,
+    path.join(candidate, 'index.html'),
+    path.join(dist, `${safePath}.html`),
+  ];
+
+  for (const file of candidates) {
+    try {
+      const fileStat = await stat(file);
+      if (fileStat.isFile()) return file;
+    } catch {
+      // Try the next candidate.
+    }
+  }
+
+  return null;
+}
+
+const MIME = {
+  '.html': 'text/html; charset=utf-8',
+  '.css': 'text/css; charset=utf-8',
+  '.js': 'text/javascript; charset=utf-8',
+  '.svg': 'image/svg+xml',
+  '.png': 'image/png',
+  '.jpg': 'image/jpeg',
+  '.jpeg': 'image/jpeg',
+  '.webp': 'image/webp',
+  '.avif': 'image/avif',
+  '.ico': 'image/x-icon',
+  '.woff': 'font/woff',
+  '.woff2': 'font/woff2',
+  '.mp4': 'video/mp4',
+  '.webm': 'video/webm',
+  '.vtt': 'text/vtt; charset=utf-8',
+  '.pdf': 'application/pdf',
+};
+
+export function contentType(file) {
+  const ext = path.extname(file).toLowerCase();
+  return MIME[ext] ?? 'application/octet-stream';
+}
+
+// Serves dist/ on an ephemeral localhost port, falling back to 404.html.
+// Returns the server (callers own closing it) and the assigned port.
+export async function startDistServer() {
+  const server = createServer(async (req, res) => {
+    try {
+      const file = (await resolveFile(req.url ?? '/')) ?? path.join(dist, '404.html');
+      const body = await readFile(file);
+      res.writeHead(200, { 'content-type': contentType(file) });
+      res.end(body);
+    } catch (error) {
+      res.writeHead(500, { 'content-type': 'text/plain; charset=utf-8' });
+      res.end(String(error));
+    }
+  });
+
+  await new Promise((resolve) => server.listen(0, '127.0.0.1', resolve));
+  return { server, port: server.address().port };
+}