From 405998ad51a96775df44b9231d44b2902819fc47 Mon Sep 17 00:00:00 2001
From: Paul Bakaus <paul.bakaus@gmail.com>
Date: Mon, 31 Aug 2026 16:43:21 -0700
Subject: [PATCH] Normalize sheriff exemption labels

AI-assisted: implemented and validated by Codex under maintainer direction.
---
 scripts/github/sheriff.mjs    | 11 +++++++++--
 tests/github-sheriff.test.mjs |  8 +++++++-
 2 files changed, 16 insertions(+), 3 deletions(-)

diff --git a/scripts/github/sheriff.mjs b/scripts/github/sheriff.mjs
index 76a78eec7..0cbbb4f8e 100644
--- a/scripts/github/sheriff.mjs
+++ b/scripts/github/sheriff.mjs
@@ -50,6 +50,10 @@ const CONTRIBUTOR_POLICY_LABELS = new Set([
 ]);
 const SHERIFF_WAIT_COMMAND = /^\/sheriff\s+wait\s*$/i;
 
+function normalizeLabelName(label) {
+  return String(label || '').trim().toLowerCase();
+}
+
 const PR_QUERY = `
 query($owner: String!, $name: String!, $after: String) {
   repository(owner: $owner, name: $name) {
@@ -145,7 +149,9 @@ export function evaluatePullRequest(pr, options = {}) {
   const closeDays = Number.isFinite(options.closeDays) ? options.closeDays : 14;
   const maintainers = loginSet(options.maintainers || DEFAULT_MAINTAINERS);
   const regularContributors = loginSet(options.regularContributors || DEFAULT_REGULAR_CONTRIBUTORS);
-  const exemptLabels = new Set(options.exemptLabels || DEFAULT_EXEMPT_LABELS);
+  const exemptLabels = new Set(
+    (options.exemptLabels || DEFAULT_EXEMPT_LABELS).map(normalizeLabelName),
+  );
   const trustedMarkerAuthors = loginSet(options.trustedMarkerAuthors || DEFAULT_TRUSTED_MARKER_AUTHORS);
   const autoCloseRegulars = options.autoCloseRegulars === true;
 
@@ -266,7 +272,8 @@ export function evaluatePullRequest(pr, options = {}) {
   const warningAlreadyPosted = Boolean(warningPostedAt
     && (!contributorActionBlockerAt || !isAfter(contributorActionBlockerAt, warningPostedAt)));
   const closeAlreadyPosted = hasMarker(pr.comments, CLOSE_MARKER, trustedMarkerAuthors);
-  const exemptFromClose = [...labels].some((label) => exemptLabels.has(label));
+  const exemptFromClose = [...labels]
+    .some((label) => exemptLabels.has(normalizeLabelName(label)));
   const regularContributor = regularContributors.has(author);
   const shouldWarn = staleEligible && !warningAlreadyPosted;
   const shouldClose = contributorActionRequired
diff --git a/tests/github-sheriff.test.mjs b/tests/github-sheriff.test.mjs
index fb916275f..80de7d974 100644
--- a/tests/github-sheriff.test.mjs
+++ b/tests/github-sheriff.test.mjs
@@ -691,13 +691,19 @@ describe('github sheriff', () => {
       ],
     };
     const closePlan = evaluatePullRequest(pr(source), { now: NOW, autoCloseRegulars: true });
-    const exemptPlan = evaluatePullRequest(pr({ ...source, labels: ['do not close'] }), {
+    const exemptPlan = evaluatePullRequest(pr({ ...source, labels: ['Do Not Close'] }), {
       now: NOW,
       autoCloseRegulars: true,
     });
+    const customExemptPlan = evaluatePullRequest(pr({ ...source, labels: ['Keep Open'] }), {
+      now: NOW,
+      autoCloseRegulars: true,
+      exemptLabels: ['keep open'],
+    });
 
     assert.equal(closePlan.shouldClose, true);
     assert.equal(exemptPlan.shouldClose, false);
+    assert.equal(customExemptPlan.shouldClose, false);
   });
 
   it('keeps stale comments idempotent', () => {