From 13a17b8e28a190d10ccfd2df47c4c9dfa095d1ff Mon Sep 17 00:00:00 2001
From: Vera Kahn <verakahn@nypl.org>
Date: Thu, 12 Sep 2024 14:53:57 -0400
Subject: [PATCH] update sort method

---
 lib/util.js       | 15 ++++++++++++++-
 test/util.test.js |  2 +-
 2 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/lib/util.js b/lib/util.js
index 2cdbe1ba..0fe77078 100644
--- a/lib/util.js
+++ b/lib/util.js
@@ -2,7 +2,20 @@ const logger = require('./logger')
 const isItemNyplOwned = require('./ownership_determination').isItemNyplOwned
 
 exports.sortOnPropWithUndefinedLast = (property) => {
-  return (a, b) => a[property]?.[0] || Number.MAX_SAFE_INTEGER > b[property]?.[0] || Number.MAX_SAFE_INTEGER ? -1 : 1
+  return function (a, b) {
+    // equal items sort equally
+    if (a[property]?.[0] === b[property]?.[0]) {
+      return 0
+    }
+    // nulls sort after anything else
+    if (!a[property]?.[0]) {
+      return 1
+    }
+    if (!b[property]?.[0]) {
+      return -1
+    }
+    return a[property]?.[0] > b[property]?.[0] ? -1 : 1
+  }
 }
 
 exports.buildJsonLdContext = function (prefixes) {
diff --git a/test/util.test.js b/test/util.test.js
index 8625ce0a..39a1a138 100644
--- a/test/util.test.js
+++ b/test/util.test.js
@@ -4,7 +4,7 @@ const mangledEnumerationChronologyItems = require('./fixtures/mangled_enumeratio
 const util = require('../lib/util')
 
 describe('Util', function () {
-  describe.only('sortOnPropWithUndefinedLast', () => {
+  describe('sortOnPropWithUndefinedLast', () => {
     it('sorts undefined last', () => {
       const sortedItemEnums = mangledEnumerationChronologyItems
         .sort(util.sortOnPropWithUndefinedLast('enumerationChronology_sort'))