1#!/usr/bin/env node
2/**
3 * Impeccable design hook — PostToolUse entry point.
4 *
5 * Reads the Claude Code / Codex / Cursor hook event from stdin, runs the design
6 * detector against the touched file, and emits a system reminder via
7 * `hookSpecificOutput.additionalContext` when findings exist.
8 *
9 * Contract: never break a turn. Always exit 0. Clean files emit a small ack
10 * unless quiet mode is enabled.
11 *
12 * Most logic lives in `hook-lib.mjs` so it is unit-testable without a
13 * subprocess. This file is the thin stdin/stdout adapter.
14 */
15 
16import { runHook, writeAuditLog } from './hook-lib.mjs';
17 
18async function readStdin() {
19  if (process.stdin.isTTY) return '';
20  const chunks = [];
21  for await (const chunk of process.stdin) chunks.push(chunk);
22  return Buffer.concat(chunks).toString('utf-8');
23}
24 
25async function main() {
26  // Snapshot the inherited env FIRST so the re-entrancy guard checks the
27  // parent's value, not the value we are about to export for any child
28  // processes the hook might ever spawn.
29  const inheritedEnv = { ...process.env };
30  process.env.IMPECCABLE_HOOK_DEPTH = process.env.IMPECCABLE_HOOK_DEPTH || '1';
31 
32  let stdinJson = '';
33  try { stdinJson = await readStdin(); } catch { /* fall through */ }
34 
35  const result = await runHook({
36    stdinJson,
37    env: inheritedEnv,
38    cwd: process.cwd(),
39  });
40 
41  writeAuditLog(process.env, result.audit, process.cwd());
42 
43  if (result.stdout) process.stdout.write(result.stdout);
44  process.exit(result.exitCode || 0);
45}
46 
47main().catch((err) => {
48  // Last-ditch: never break the agent's turn even if something we did not
49  // anticipate goes wrong. Audit-log the failure if logging is enabled.
50  try {
51    writeAuditLog(process.env, {
52      ts: new Date().toISOString(),
53      event: 'PostToolUse',
54      error: String(err && err.message ? err.message : err),
55    });
56  } catch { /* swallow */ }
57  if (process.env.IMPECCABLE_HOOK_DEBUG) {
58    process.stderr.write(`[impeccable-hook] ${err}\n`);
59  }
60  process.exit(0);
61});
62