From eb94bdb05af2580bcf7f01a5b762f82f116514fb Mon Sep 17 00:00:00 2001
From: Denys Poltorak <itwfrontend@gmail.com>
Date: Thu, 3 Aug 2023 14:59:39 +0300
Subject: [PATCH] refactor: add array check

---
 src/arrayMethodJoin.js | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/arrayMethodJoin.js b/src/arrayMethodJoin.js
index cb39c800..fb37e954 100644
--- a/src/arrayMethodJoin.js
+++ b/src/arrayMethodJoin.js
@@ -9,6 +9,11 @@ const isNotIgnoredEl = (el) => ![null, undefined].includes(el);
 function applyCustomJoin() {
   [].__proto__.join2 = function(separator = ',') {
     const currentArray = this;
+
+    if (!(currentArray instanceof Array)) {
+      return '';
+    }
+
     const INDEX_OF_LAST_ELEMENT = currentArray.length - 1;
 
     let concatedString = '';