fix: bug Arr::flatten

Author: dimtrovich

Iterable/Arr.php

@@ -554,6 +554,32 @@ public static function first(iterable $array, ?callable $callback = null, mixed
         return Helpers::value($default);
     }
 
+    /**
+     * Flatten a multi-dimensional array into a single level.
+     */
+    public static function flatten(array $array, float|int $depth = INF): array
+    {
+        $result = [];
+
+        foreach ($array as $item) {
+            $item = $item instanceof Collection ? $item->all() : $item;
+
+            if (! is_array($item)) {
+                $result[] = $item;
+            } else {
+                $values = $depth === 1
+                    ? array_values($item)
+                    : static::flatten($item, $depth - 1);
+
+                foreach ($values as $value) {
+                    $result[] = $value;
+                }
+            }
+        }
+
+        return $result;
+    }
+
     /**
      * Collapses a multi-dimensional array into a single dimension, using a delimited array path for
      * each array element's key, i.e. array(array('Foo' => array('Bar' => 'Far'))) becomes
@@ -564,7 +590,7 @@ public static function first(iterable $array, ?callable $callback = null, mixed
      *
      * @credit http://book.cakephp.org/2.0/en/core-utility-libraries/hash.html#Hash::flatten
      */
-    public static function flatten(array $data, string $separator = '.'): array
+    public static function flattenSeparator(array $data, string $separator = '.'): array
     {
         $result = [];
         $stack  = [];

Iterable/Collection.php

@@ -360,7 +360,7 @@ public function first(?callable $callback = null, $default = null)
     /**
      * {@inheritDoc}
      */
-    public function flatten(int $depth = INF)
+    public function flatten(float|int $depth = INF)
     {
         return new static(Arr::flatten($this->items, $depth));
     }