Update chunk-array.md

Author: LuziferSenpai

snippets/javascript/array-manipulation/chunk-array.md

@@ -10,7 +10,7 @@ function chunkArray(array, chunkSize) {
     if (!Array.isArray(array)) {
         throw new TypeError('Expected an array as the first argument.');
     }
-    if (typeof chunkSize !== 'number' || chunkSize <= 0) {
+    if (typeof chunkSize !== 'number' || Number.isNaN(chunkSize) || chunkSize <= 0) {
         throw new RangeError('Chunk size must be a positive number.');
     }
 
@@ -30,4 +30,4 @@ function chunkArray(array, chunkSize) {
 // Usage:
 const data = [1, 2, 3, 4, 5, 6, 7, 8];
 const chunked = chunkArray(data, 3); // Returns: [[1, 2, 3], [4, 5, 6], [7, 8]]
-```
+```