#!/usr/bin/env node
|
/**
|
* Impeccable design hook — Cursor preToolUse write gate.
|
*
|
* Cursor's stop hook is not consistently dispatched by the headless agent, so
|
* this hook checks proposed Write/Edit content before it lands. It only denies
|
* writes when the real detector finds an issue in the proposed UI content.
|
*
|
* Contract: never break a turn accidentally. On malformed input or internal
|
* errors, allow the tool and exit 0.
|
*/
|
|
import fs from 'node:fs';
|
import os from 'node:os';
|
import path from 'node:path';
|
|
import {
|
ALLOWED_EXTS,
|
EDIT_COUNT_THRESHOLD,
|
GENERATED_PATH,
|
SENSITIVE_PATH,
|
appendDesignSystemNote,
|
designSystemOptions,
|
filterFindings,
|
isNativePlatform,
|
isScanTargetInsideProject,
|
loadDetector,
|
matchConfiguredExtension,
|
matchesAnyGlob,
|
persistCache,
|
readCache,
|
readConfig,
|
renderTemplate,
|
resolveCacheCwd,
|
resolveProjectCwd,
|
resolveProjectPlatform,
|
truthy,
|
writeAuditLog,
|
} from './hook-lib.mjs';
|
|
async function readStdin() {
|
if (process.stdin.isTTY) return '';
|
const chunks = [];
|
for await (const chunk of process.stdin) chunks.push(chunk);
|
return Buffer.concat(chunks).toString('utf-8');
|
}
|
|
function done(payload = null) {
|
if (payload) process.stdout.write(JSON.stringify(payload));
|
process.exit(0);
|
}
|
|
function allow(extra = {}, payload = {}) {
|
writeAuditLog(process.env, {
|
ts: new Date().toISOString(),
|
event: 'preToolUse',
|
...extra,
|
});
|
return done({ permission: 'allow', ...payload });
|
}
|
|
function deny(message, audit) {
|
writeAuditLog(process.env, {
|
ts: new Date().toISOString(),
|
event: 'preToolUse',
|
blocked: true,
|
...audit,
|
});
|
return done({
|
permission: 'deny',
|
user_message: message,
|
agent_message: message,
|
});
|
}
|
|
function toolInput(event) {
|
return event?.tool_input && typeof event.tool_input === 'object' ? event.tool_input : {};
|
}
|
|
function proposedFilePath(event, cwd) {
|
const input = toolInput(event);
|
const raw = input.file_path || input.path || input.target_file || event?.file_path;
|
const candidate = typeof raw === 'string' && raw.trim()
|
? raw
|
: shellWriteDestination(shellCommand(input));
|
if (typeof candidate !== 'string' || !candidate.trim()) return '';
|
return path.isAbsolute(candidate) ? candidate : path.resolve(cwd, candidate);
|
}
|
|
function proposedContent(event, cwd, filePath) {
|
const input = toolInput(event);
|
for (const key of ['content', 'streamContent', 'text']) {
|
if (typeof input[key] === 'string') return input[key];
|
}
|
|
const editProjection = projectedEditContent(input, filePath, cwd);
|
if (editProjection !== undefined) return editProjection;
|
|
if (hasFragmentEditContent(input)) {
|
return { skipped: 'fragment-only-edit' };
|
}
|
|
const command = shellCommand(input);
|
const pythonContent = shellPythonWriteContent(command);
|
if (pythonContent) return pythonContent;
|
const shellContent = shellHereDocContent(command);
|
if (shellContent) return shellContent;
|
const copiedContent = shellCopiedFileContent(command, cwd);
|
if (copiedContent) return copiedContent;
|
return '';
|
}
|
|
function hasFragmentEditContent(input) {
|
if (!input || typeof input !== 'object') return false;
|
if (typeof input.new_string === 'string' || typeof input.newString === 'string' || typeof input.new_str === 'string' || typeof input.replacement === 'string') {
|
return true;
|
}
|
return Array.isArray(input.edits) && input.edits.some((edit) => edit && typeof edit === 'object');
|
}
|
|
function projectedEditContent(input, filePath, cwd) {
|
if (!filePath) return undefined;
|
const singleOld = firstString(input, ['old_string', 'oldString', 'old_str', 'target']);
|
const singleNew = firstString(input, ['new_string', 'newString', 'new_str', 'replacement']);
|
if (singleOld !== undefined || singleNew !== undefined) {
|
if (singleOld === undefined || singleNew === undefined) return { skipped: 'fragment-only-edit' };
|
const original = readExistingProjectFile(filePath, cwd);
|
if (original === null) return { skipped: 'edit-original-unreadable' };
|
const projected = replaceOnce(original, singleOld, singleNew);
|
return projected === null ? { skipped: 'edit-old-string-missing' } : projected;
|
}
|
|
if (!Array.isArray(input.edits)) return undefined;
|
const original = readExistingProjectFile(filePath, cwd);
|
if (original === null) return { skipped: 'edit-original-unreadable' };
|
|
let projected = original;
|
for (const edit of input.edits) {
|
if (!edit || typeof edit !== 'object') return { skipped: 'fragment-only-edit' };
|
const oldString = firstString(edit, ['old_string', 'oldString', 'old_str', 'target']);
|
const newString = firstString(edit, ['new_string', 'newString', 'new_str', 'replacement']);
|
if (oldString === undefined || newString === undefined) return { skipped: 'fragment-only-edit' };
|
const next = replaceOnce(projected, oldString, newString);
|
if (next === null) return { skipped: 'edit-old-string-missing' };
|
projected = next;
|
}
|
return projected;
|
}
|
|
function firstString(obj, keys) {
|
for (const key of keys) {
|
if (typeof obj?.[key] === 'string') return obj[key];
|
}
|
return undefined;
|
}
|
|
function replaceOnce(original, oldString, newString) {
|
if (oldString === '') return null;
|
const index = original.indexOf(oldString);
|
if (index === -1) return null;
|
return `${original.slice(0, index)}${newString}${original.slice(index + oldString.length)}`;
|
}
|
|
function readExistingProjectFile(filePath, cwd) {
|
if (!isScanTargetInsideProject(filePath, cwd)) return null;
|
if (SENSITIVE_PATH.test(filePath) || GENERATED_PATH.test(filePath)) return null;
|
try {
|
const stat = fs.statSync(filePath);
|
if (!stat.isFile() || stat.size > 1024 * 1024) return null;
|
return fs.readFileSync(filePath, 'utf-8');
|
} catch {
|
return null;
|
}
|
}
|
|
function shellCommand(input) {
|
if (typeof input.command === 'string') return input.command;
|
if (input.args && typeof input.args.command === 'string') return input.args.command;
|
return '';
|
}
|
|
function shellRedirectPath(command) {
|
if (!command || typeof command !== 'string') return '';
|
const match = command.match(/(?:^|[\s;&|])(?:>>?|1>>?)\s*(?:"([^"]+)"|'([^']+)'|([^<>\s]+))/);
|
return (match?.[1] || match?.[2] || match?.[3] || '').trim();
|
}
|
|
function shellWriteDestination(command) {
|
return shellRedirectPath(command) || shellTeeDestination(command) || shellCopyPaths(command)?.dest || shellPythonWriteDestination(command) || '';
|
}
|
|
function shellPythonWriteDestination(command) {
|
if (!/\bpython(?:3)?\b/.test(command || '')) return '';
|
const directPath = firstMatch(command, /(?:^|[^\w.])(?:pathlib\.)?Path\(\s*(["'])(.*?)\1\s*\)\s*\.write_text\s*\(/);
|
if (directPath) return directPath;
|
|
const pathsByVar = new Map();
|
const assignmentRe = /\b([A-Za-z_]\w*)\s*=\s*(?:pathlib\.)?Path\(\s*(["'])(.*?)\2\s*\)/g;
|
let assignment;
|
while ((assignment = assignmentRe.exec(command))) {
|
pathsByVar.set(assignment[1], assignment[3]);
|
}
|
|
const writeVarRe = /\b([A-Za-z_]\w*)\.write_text\s*\(/g;
|
let writeVar;
|
while ((writeVar = writeVarRe.exec(command))) {
|
const candidate = pathsByVar.get(writeVar[1]);
|
if (candidate) return candidate;
|
}
|
|
return firstMatch(command, /\bopen\(\s*(["'])(.*?)\1\s*,\s*(["'])[wax](?:\+)?b?\3/);
|
}
|
|
function firstMatch(value, re) {
|
const match = String(value || '').match(re);
|
return (match?.[2] || '').trim();
|
}
|
|
function shellTeeDestination(command) {
|
const words = shellWords(command);
|
const teeIndex = words.findIndex((word) => path.basename(word) === 'tee');
|
if (teeIndex === -1) return '';
|
for (const word of words.slice(teeIndex + 1)) {
|
if (['&&', '||', ';', '|'].includes(word)) break;
|
if (word === '--') continue;
|
if (word.startsWith('-')) continue;
|
return word;
|
}
|
return '';
|
}
|
|
function shellCopiedFileContent(command, cwd) {
|
const source = shellCopyPaths(command)?.source;
|
if (!source) return '';
|
const sourcePath = path.isAbsolute(source) ? source : path.resolve(cwd, source);
|
if (!isScanTargetInsideProject(sourcePath, cwd)) return '';
|
if (SENSITIVE_PATH.test(sourcePath) || GENERATED_PATH.test(sourcePath)) return '';
|
try {
|
const stat = fs.statSync(sourcePath);
|
if (!stat.isFile() || stat.size > 1024 * 1024) return '';
|
return fs.readFileSync(sourcePath, 'utf-8');
|
} catch {
|
return '';
|
}
|
}
|
|
function shellCopyPaths(command) {
|
const words = shellWords(command);
|
if (words.length < 3 || path.basename(words[0]) !== 'cp') return null;
|
const args = [];
|
for (const word of words.slice(1)) {
|
if (['&&', '||', ';', '|'].includes(word)) break;
|
if (word === '--') continue;
|
if (word.startsWith('-')) continue;
|
args.push(word);
|
}
|
if (args.length < 2) return null;
|
return { source: args[args.length - 2], dest: args[args.length - 1] };
|
}
|
|
function shellWords(command) {
|
if (!command || typeof command !== 'string') return [];
|
const words = [];
|
const re = /"((?:\\"|[^"])*)"|'((?:\\'|[^'])*)'|([^\s]+)/g;
|
let match;
|
while ((match = re.exec(command))) {
|
words.push((match[1] ?? match[2] ?? match[3] ?? '').replace(/\\(["'])/g, '$1'));
|
}
|
return words;
|
}
|
|
function shellHereDocContent(command) {
|
if (!command || typeof command !== 'string') return '';
|
const markerMatch = command.match(/<<-?\s*['"]?([A-Za-z0-9_.-]+)['"]?[^\r\n]*\r?\n/);
|
if (!markerMatch) return '';
|
const marker = markerMatch[1];
|
const start = (markerMatch.index || 0) + markerMatch[0].length;
|
const rest = command.slice(start);
|
const endRe = new RegExp(`\\r?\\n${escapeRegExp(marker)}(?:\\r?\\n|$)`);
|
const end = rest.search(endRe);
|
return end >= 0 ? rest.slice(0, end) : '';
|
}
|
|
function shellPythonWriteContent(command) {
|
if (!/\bpython(?:3)?\b/.test(command || '')) return '';
|
const script = shellHereDocContent(command) || command;
|
return pythonStringArg(script, /\.write_text\s*\(\s*/g) || pythonStringArg(script, /\.write\s*\(\s*/g);
|
}
|
|
function pythonStringArg(script, prefixRe) {
|
let prefix;
|
while ((prefix = prefixRe.exec(script))) {
|
const start = prefixRe.lastIndex;
|
const triple = script.slice(start, start + 3);
|
if (triple === "'''" || triple === '"""') {
|
const end = script.indexOf(triple, start + 3);
|
if (end !== -1) return script.slice(start + 3, end);
|
continue;
|
}
|
const quote = script[start];
|
if (quote !== '"' && quote !== "'") continue;
|
let out = '';
|
for (let i = start + 1; i < script.length; i++) {
|
const ch = script[i];
|
if (ch === '\\') {
|
out += script[i + 1] || '';
|
i += 1;
|
} else if (ch === quote) {
|
return out;
|
} else {
|
out += ch;
|
}
|
}
|
}
|
return '';
|
}
|
|
function escapeRegExp(value) {
|
return String(value).replace(/[.*+?^${}()|[\]\\]/g, '\\$&');
|
}
|
|
function relativePath(filePath, cwd) {
|
try {
|
const rel = path.relative(cwd, filePath);
|
if (!rel || rel.startsWith('..') || path.isAbsolute(rel)) return filePath;
|
return rel.split(path.sep).join('/');
|
} catch {
|
return filePath;
|
}
|
}
|
|
// The static HTML engine reads its input from disk, but preToolUse only has
|
// the proposed content. Stage it in a temp file so html-engine targets get the
|
// same DOM-structural rules pre-write that runHook applies post-edit.
|
async function detectProposedHtml(detector, content, filePath, scanOptions) {
|
const dir = fs.mkdtempSync(path.join(os.tmpdir(), 'impeccable-pre-'));
|
const tmpFile = path.join(dir, path.basename(filePath));
|
try {
|
fs.writeFileSync(tmpFile, content);
|
const findings = await detector.detectHtml(tmpFile, scanOptions);
|
// Findings carry the temp path; remap so file-scoped ignores still match.
|
return (findings || []).map((f) => (f && typeof f === 'object' ? { ...f, file: filePath } : f));
|
} finally {
|
fs.rmSync(dir, { recursive: true, force: true });
|
}
|
}
|
|
function cursorBlockMessage(findings, filePath, config, cwd) {
|
const rendered = renderTemplate(findings, filePath, config, { cwd });
|
const blocked = rendered.replace(
|
'[impeccable@1] Design hook findings requiring review',
|
'[impeccable@1] Impeccable design hook blocked this write before it landed. Design hook findings requiring review',
|
);
|
return blocked.length > 4000 ? `${blocked.slice(0, 3984)}\n...(truncated)` : blocked;
|
}
|
|
function findingSignature(findings) {
|
return findings
|
.map((finding) => `${finding.antipattern || 'unknown'}:${finding.line || 0}`)
|
.sort()
|
.join('|');
|
}
|
|
function bumpCursorDenial(cache, sessionId, filePath, findings) {
|
const session = cache.sessions[sessionId] || { updatedAt: Date.now(), files: {} };
|
cache.sessions[sessionId] = session;
|
session.updatedAt = Date.now();
|
const fileEntry = session.files[filePath] || { editCount: 0, findings: [] };
|
session.files[filePath] = fileEntry;
|
const key = findingSignature(findings);
|
fileEntry.cursorDenials = fileEntry.cursorDenials && typeof fileEntry.cursorDenials === 'object'
|
? fileEntry.cursorDenials
|
: {};
|
fileEntry.cursorDenials[key] = (fileEntry.cursorDenials[key] || 0) + 1;
|
return { key, count: fileEntry.cursorDenials[key] };
|
}
|
|
async function main() {
|
if (truthy(process.env.IMPECCABLE_HOOK_DISABLED)) {
|
return allow({ skipped: 'env-disabled' });
|
}
|
|
let event = null;
|
try {
|
const raw = await readStdin();
|
if (raw) event = JSON.parse(raw);
|
} catch {
|
return allow({ skipped: 'stdin-malformed' });
|
}
|
|
if (!event || typeof event !== 'object') {
|
return allow({ skipped: 'stdin-empty' });
|
}
|
|
const sessionCwd = resolveProjectCwd(event);
|
const started = Date.now();
|
const filePath = proposedFilePath(event, sessionCwd);
|
// Re-key config/cache to the edited file's project root when the session
|
// was launched from a non-project umbrella directory (issue #305).
|
const cwd = resolveCacheCwd(filePath, sessionCwd);
|
const audit = {
|
harness: 'cursor',
|
cwd,
|
tool: event.tool_name || null,
|
file: filePath || null,
|
};
|
|
if (!filePath) return allow({ ...audit, skipped: 'no-file-path', durationMs: Date.now() - started });
|
if (!isScanTargetInsideProject(filePath, cwd)) return allow({ ...audit, skipped: 'outside-project', durationMs: Date.now() - started });
|
if (SENSITIVE_PATH.test(filePath)) return allow({ ...audit, skipped: 'sensitive', durationMs: Date.now() - started });
|
if (GENERATED_PATH.test(filePath)) return allow({ ...audit, skipped: 'generated', durationMs: Date.now() - started });
|
|
// Config is read before the extension gate so `detector.extensions` entries
|
// (e.g. `.blade.php` template files, issue #316) can widen it.
|
const config = readConfig(cwd);
|
const ext = path.extname(filePath).toLowerCase();
|
const configuredExt = matchConfiguredExtension(filePath, config.extensions);
|
audit.ext = configuredExt ? configuredExt.ext : ext;
|
if (!ALLOWED_EXTS.has(ext) && !configuredExt) return allow({ ...audit, skipped: 'extension', durationMs: Date.now() - started });
|
|
const contentResult = proposedContent(event, cwd, filePath);
|
if (contentResult && typeof contentResult === 'object' && contentResult.skipped) {
|
return allow({ ...audit, skipped: contentResult.skipped, durationMs: Date.now() - started });
|
}
|
const content = typeof contentResult === 'string' ? contentResult : '';
|
if (!content) return allow({ ...audit, skipped: 'no-proposed-content', durationMs: Date.now() - started });
|
|
if (config.enabled === false) return allow({ ...audit, skipped: 'config-disabled', durationMs: Date.now() - started });
|
|
// Web rule engine, native project: stand aside (see resolveProjectPlatform).
|
const platform = resolveProjectPlatform(cwd);
|
if (isNativePlatform(platform)) {
|
return allow({ ...audit, skipped: 'native-platform', platform, durationMs: Date.now() - started });
|
}
|
|
const rel = relativePath(filePath, cwd);
|
if (matchesAnyGlob(rel, config.ignoreFiles) || matchesAnyGlob(filePath, config.ignoreFiles)) {
|
return allow({ ...audit, skipped: 'config-ignore-file', durationMs: Date.now() - started });
|
}
|
|
const detector = await loadDetector();
|
if (!detector || typeof detector.detectText !== 'function') {
|
return allow({ ...audit, skipped: 'detector-missing', durationMs: Date.now() - started });
|
}
|
const scanOptions = designSystemOptions(config, detector, cwd);
|
|
// Mirror runHook's engine routing so template issues the HTML engine catches
|
// post-edit cannot slip past the pre-write gate.
|
const useHtmlEngine = configuredExt
|
? configuredExt.engine === 'html'
|
: (ext === '.html' || ext === '.htm');
|
let findings = [];
|
try {
|
findings = useHtmlEngine && typeof detector.detectHtml === 'function'
|
? await detectProposedHtml(detector, content, filePath, scanOptions)
|
: await detector.detectText(content, filePath, scanOptions);
|
} catch {
|
return allow({ ...audit, error: 'detector-threw', durationMs: Date.now() - started });
|
}
|
|
const filtered = filterFindings(findings || [], content, ext, config);
|
if (filtered.length === 0) {
|
return allow({
|
...audit,
|
findings: (findings || []).length,
|
blockedFindings: 0,
|
durationMs: Date.now() - started,
|
});
|
}
|
|
const message = appendDesignSystemNote(cursorBlockMessage(filtered, filePath, config, cwd), scanOptions);
|
const sessionId = event.session_id || event.conversation_id || 'unknown';
|
const cache = readCache(cwd);
|
const denial = bumpCursorDenial(cache, sessionId, filePath, filtered);
|
persistCache(cwd, cache);
|
if (denial.count > EDIT_COUNT_THRESHOLD) {
|
const warning = `${message}\n\nThis is the ${denial.count}th repeated denial for the same file and finding signature, so Impeccable is allowing this write to avoid a loop. Reconsider the issue immediately after the tool runs.`;
|
return allow({
|
...audit,
|
findings: (findings || []).length,
|
blockedFindings: filtered.length,
|
cursorDenialKey: denial.key,
|
cursorDenialCount: denial.count,
|
downgraded: true,
|
chars: warning.length,
|
durationMs: Date.now() - started,
|
}, {
|
user_message: warning,
|
agent_message: warning,
|
});
|
}
|
return deny(message, {
|
...audit,
|
findings: (findings || []).length,
|
blockedFindings: filtered.length,
|
cursorDenialKey: denial.key,
|
cursorDenialCount: denial.count,
|
chars: message.length,
|
durationMs: Date.now() - started,
|
});
|
}
|
|
main().catch((err) => {
|
if (process.env.IMPECCABLE_HOOK_DEBUG) {
|
process.stderr.write(`[impeccable-hook-before-edit] ${err}\n`);
|
}
|
done({ permission: 'allow' });
|
});
|
