feat(phase0): complete GC1 feasibility and GC2 shared format contracts

- Record user evidence for directory fallback to complete GC1 (10/10 checks passed) - Expand Format Specification 0.1 to Revision 0.2 with normative shared contracts - Author JSON Schema Draft-07 at schema/xzbt-0.1.schema.json - Implement zero-dependency semantic validator at tools/validate-exhibit.mjs - Create 12-case conformance fixture suite and automated test runner (12/12 passing) - Update implementation status, verification gates, and gap closure decisions - Add devlog entry covering stall recovery and Phase 0 current state
2026-09-05 11:38:48 -07:00
parent ca2830174f
commit e02d49a739
25 changed files with 2473 additions and 66 deletions
@@ -0,0 +1,89 @@
+/**
+ * Dependency-free local development server for XZBT.
+ *
+ * It deliberately binds only to loopback. It is not part of the distributed
+ * XZBT artifact and cannot establish direct-file Phase 0 feasibility results.
+ */
+import { createReadStream, statSync } from 'node:fs';
+import { createServer } from 'node:http';
+import { extname, normalize, resolve, sep } from 'node:path';
+import { fileURLToPath } from 'node:url';
+
+const root = resolve(fileURLToPath(new URL('..', import.meta.url)));
+const host = '127.0.0.1';
+const loopbackAddresses = ['127.0.0.1', '::1'];
+const port = Number.parseInt(process.env.XZBT_DEV_PORT ?? '5173', 10);
+
+if (!Number.isInteger(port) || port < 1 || port > 65535) {
+  throw new Error('XZBT_DEV_PORT must be an integer from 1 through 65535.');
+}
+
+const mimeTypes = new Map([
+  ['.css', 'text/css; charset=utf-8'],
+  ['.html', 'text/html; charset=utf-8'],
+  ['.js', 'text/javascript; charset=utf-8'],
+  ['.json', 'application/json; charset=utf-8'],
+  ['.mjs', 'text/javascript; charset=utf-8'],
+  ['.xzbt', 'application/json; charset=utf-8'],
+]);
+
+function requestedPath(requestUrl) {
+  const pathname = new URL(requestUrl, `http://${host}:${port}`).pathname;
+  const decodedPath = decodeURIComponent(pathname);
+  if (decodedPath.includes('\0')) return null;
+  if (decodedPath.split('/').some((segment) => segment.startsWith('.'))) return null;
+
+  const relativePath = decodedPath === '/'
+    ? 'prototypes/phase0/XZBT-phase0-probe.html'
+    : decodedPath.replace(/^\/+/, '');
+  const candidate = resolve(root, normalize(relativePath));
+  return candidate === root || candidate.startsWith(`${root}${sep}`) ? candidate : null;
+}
+
+function handleRequest(request, response) {
+  if (!['GET', 'HEAD'].includes(request.method ?? '')) {
+    response.writeHead(405, { Allow: 'GET, HEAD' }).end();
+    return;
+  }
+
+  let path;
+  try {
+    path = requestedPath(request.url ?? '/');
+  } catch {
+    response.writeHead(400).end('Malformed request path.');
+    return;
+  }
+  if (!path) {
+    response.writeHead(403).end('Path is outside the XZBT workspace.');
+    return;
+  }
+
+  let stats;
+  try {
+    stats = statSync(path);
+  } catch {
+    response.writeHead(404).end('Not found.');
+    return;
+  }
+  if (!stats.isFile()) {
+    response.writeHead(404).end('Not found.');
+    return;
+  }
+
+  response.writeHead(200, {
+    'Content-Length': stats.size,
+    'Content-Type': mimeTypes.get(extname(path).toLowerCase()) ?? 'application/octet-stream',
+    'Cache-Control': 'no-store',
+    'X-Content-Type-Options': 'nosniff',
+  });
+  if (request.method === 'HEAD') response.end();
+  else createReadStream(path).pipe(response);
+}
+
+for (const address of loopbackAddresses) {
+  const server = createServer(handleRequest);
+  server.listen(port, address, () => {
+    console.log(`XZBT development server: http://${address}:${port}/`);
+  });
+}
+console.log(`Serving workspace root: ${root}`);