Fix: sync Stop finding cache after a clean Grok scan

A clean Stop never replaced remembered keys, so a finding that was fixed and then reintroduced stayed silent. Remember the live scan, including empty, and persist that write.

Prepared with AI assistance.

Co-authored-by: Cursor <cursoragent@cursor.com>

skill/scripts/hook-lib.mjs

@@ -2323,6 +2323,7 @@ export async function runStopHook({ stdinJson, env = {}, cwd = process.cwd(), no
 
     const freshGroups = [];
     let scanned = 0;
+    let cacheDirty = false;
     for (const filePath of touched) {
       if (scanned >= STOP_MAX_FILES) break;
       if (hasPathTraversal(filePath) || SENSITIVE_PATH.test(filePath)) continue;
@@ -2343,29 +2344,39 @@ export async function runStopHook({ stdinJson, env = {}, cwd = process.cwd(), no
       try { content = fs.readFileSync(filePath, 'utf-8'); } catch { continue; }
 
       let findings;
+      let detectorThrew = false;
       const useHtmlEngine = configuredExt
         ? configuredExt.engine === 'html'
         : (ext === '.html' || ext === '.htm');
 
       if (useHtmlEngine && typeof det.detectHtml === 'function') {
-        try { findings = await det.detectHtml(filePath, scanOptions); } catch { findings = []; }
+        try { findings = await det.detectHtml(filePath, scanOptions); } catch { findings = []; detectorThrew = true; }
       } else {
-        try { findings = await det.detectText(content, filePath, scanOptions); } catch { findings = []; }
+        try { findings = await det.detectText(content, filePath, scanOptions); } catch { findings = []; detectorThrew = true; }
       }
 
+      // A detector failure tells us nothing about the file. Leave whatever
+      // was remembered alone rather than recording an empty scan as truth.
+      if (detectorThrew) continue;
+
       // Full rule set: no tier split here. Config/inline ignores still apply,
       // and the session dedupe drops everything the per-edit pass (or an
       // earlier Stop pass) already surfaced.
       const filtered = filterFindings(findings || [], content, ext, config);
       const fresh = dedupeAgainstCache(filtered, cache, sessionId, filePath);
+      // Sync to the live scan, including empty. Remembering only `fresh`
+      // (or skipping the write on a clean Stop) left stale keys in place, so
+      // a finding that was fixed and later reintroduced never fired again.
+      rememberFindings(cache, sessionId, filePath, filtered);
+      cacheDirty = true;
       if (fresh.length > 0) {
-        rememberFindings(cache, sessionId, filePath, fresh);
         freshGroups.push({ filePath, findings: fresh });
       }
     }
     audit.scannedFiles = scanned;
 
     if (freshGroups.length === 0) {
+      if (cacheDirty) persistCache(projectCwd, cache);
       return result({ emitted: false, skipped: 'stop-clean', durationMs: Date.now() - started });
     }
 
@@ -2382,8 +2393,8 @@ export async function runStopHook({ stdinJson, env = {}, cwd = process.cwd(), no
     );
     commitFooterShown(cache, sessionId, text);
 
-    // Fresh findings earn the cache write so the next Stop fire is silent
-    // unless new issues appear; the notice flags ride along.
+    // Persist the live finding set so the next Stop fire is silent unless
+    // new issues appear; the notice flags ride along.
     persistCache(projectCwd, cache);
     return {
       exitCode: 0,

tests/hook.test.mjs

@@ -4099,6 +4099,56 @@ describe('runStopHook()', () => {
     assert.match(out.hookSpecificOutput.additionalContext, /marketing-buzzword/);
   });
 
+  it('Grok Stop re-emits a finding that was fixed then reintroduced', async () => {
+    // Grok PostToolUse only touches the file. Stop is the cache writer.
+    // A clean Stop must replace the remembered set with the empty scan so
+    // the same finding is not deduped away when it comes back.
+    const sid = 'grok-stop-reintro';
+    const file = write('src/Card.tsx', 'noop');
+    let current = [finding('dark-glow', 5)];
+    const det = {
+      set(next) { current = next; },
+      detectText: () => current.slice(),
+      detectHtml: () => current.slice(),
+    };
+
+    await runHook({ stdinJson: JSON.stringify(grokEditEvent(file, sid)), env: {}, cwd, detector: det });
+    const first = await runStopHook({ stdinJson: JSON.stringify(grokStopEvent(sid)), env: {}, cwd, detector: det });
+    assert.match(first.stdout, /dark-glow/);
+
+    det.set([]);
+    const clean = await runStopHook({ stdinJson: JSON.stringify(grokStopEvent(sid)), env: {}, cwd, detector: det });
+    assert.equal(clean.stdout, '');
+    assert.equal(clean.audit.skipped, 'stop-clean');
+    assert.deepEqual(readCache(cwd).sessions[sid].files[file].findings, []);
+
+    det.set([finding('dark-glow', 5)]);
+    const again = await runStopHook({ stdinJson: JSON.stringify(grokStopEvent(sid)), env: {}, cwd, detector: det });
+    assert.equal(again.audit.emitted, true);
+    assert.match(again.stdout, /dark-glow/, 'a finding fixed then reintroduced must fire at Stop again');
+  });
+
+  it('Stop remembers the live scan, not only newly emitted findings', async () => {
+    // Per-edit already remembered dark-glow. Stop then emits the deferred
+    // remainder. The cache must keep both keys so a second Stop stays silent
+    // instead of re-firing the immediate-tier finding.
+    const sid = 'stop-sync-full-set';
+    const file = write('src/Card.tsx', 'noop');
+    const det = fakeDetector([
+      finding('dark-glow', 5),
+      finding('marketing-buzzword', 3),
+    ]);
+
+    await runHook({ stdinJson: JSON.stringify(editEvent(file, sid)), env: {}, cwd, detector: det });
+    const first = await runStopHook({ stdinJson: JSON.stringify(stopEvent(sid)), env: {}, cwd, detector: det });
+    assert.match(first.stdout, /marketing-buzzword/);
+    assert.doesNotMatch(first.stdout, /dark-glow/);
+
+    const second = await runStopHook({ stdinJson: JSON.stringify(stopEvent(sid)), env: {}, cwd, detector: det });
+    assert.equal(second.stdout, '');
+    assert.equal(second.audit.skipped, 'stop-clean');
+  });
+
   it('Grok Stop shutdown is observe-only and does not emit a second deep pass (#646)', async () => {
     const sid = 'grok-shutdown';
     const file = write('src/Card.tsx', 'noop');