From 43592d6fa47f7396216196a524a4bcbef976598c Mon Sep 17 00:00:00 2001
From: 5saviahv <49443574+5saviahv@users.noreply.github.com>
Date: Mon, 4 Jan 2021 15:24:10 +0200
Subject: [PATCH] fix(traversing): parent() may fail in functions (#1637)

---
 lib/api/traversing.js  | 2 +-
 test/api/traversing.js | 6 ++++++
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/lib/api/traversing.js b/lib/api/traversing.js
index 5db3fa1b01..bd417beac8 100644
--- a/lib/api/traversing.js
+++ b/lib/api/traversing.js
@@ -86,7 +86,7 @@ exports.parent = function (selector) {
     }
   });
 
-  if (arguments.length) {
+  if (selector) {
     set = exports.filter.call(set, selector, this);
   }
 
diff --git a/test/api/traversing.js b/test/api/traversing.js
index d8e8e40c7b..6b475df1ee 100644
--- a/test/api/traversing.js
+++ b/test/api/traversing.js
@@ -619,6 +619,12 @@ describe('$(...)', function () {
       expect(result[1].attribs.id).toBe('vegetables');
     });
 
+    it('(undefined) : should not throw an exception', function () {
+      expect(function () {
+        $('li').parent(undefined);
+      }).not.toThrow();
+    });
+
     it('() : should return an empty object for top-level elements', function () {
       var result = $('html').parent();
       expect(result).toHaveLength(0);