Fixed static test failures

Author: Indraniks

app/code/Magento/Catalog/Model/ResourceModel/Category/Collection.php

@@ -155,7 +155,7 @@ public function addIdFilter($categoryIds)
             $condition = $categoryIds;
         } elseif (is_string($categoryIds)) {
             $ids = explode(',', $categoryIds);
-            if (empty($ids)) {
+            if (count($ids) == 0) {
                 $condition = $categoryIds;
             } else {
                 $condition = ['in' => $ids];