[11.x] Arr helper map spread (#50474)

* Add Arr::mapSpread helper

* Fix

* StyleCI

* Mark as static

* Fix tests

* Slim test

src/Illuminate/Collections/Arr.php

@@ -635,6 +635,24 @@ public static function mapWithKeys(array $array, callable $callback)
         return $result;
     }
 
+    /**
+     * Run a map over each nested chunk of items.
+     *
+     * @template TMapSpreadValue
+     *
+     * @param  array  $array
+     * @param  callable(mixed...): TMapSpreadValue  $callback
+     * @return array<TKey, TMapSpreadValue>
+     */
+    public static function mapSpread(array $array, callable $callback)
+    {
+        return static::map($array, function ($chunk, $key) use ($callback) {
+            $chunk[] = $key;
+
+            return $callback(...$chunk);
+        });
+    }
+
     /**
      * Push an item onto the beginning of an array.
      *

tests/Support/SupportArrTest.php

@@ -733,6 +733,21 @@ public function testMapByReference()
         $this->assertEquals(['first' => 'taylor', 'last' => 'otwell'], $data);
     }
 
+    public function testMapSpread()
+    {
+        $c = [[1, 'a'], [2, 'b']];
+
+        $result = Arr::mapSpread($c, function ($number, $character) {
+            return "{$number}-{$character}";
+        });
+        $this->assertEquals(['1-a', '2-b'], $result);
+
+        $result = Arr::mapSpread($c, function ($number, $character, $key) {
+            return "{$number}-{$character}-{$key}";
+        });
+        $this->assertEquals(['1-a-0', '2-b-1'], $result);
+    }
+
     public function testPrepend()
     {
         $array = Arr::prepend(['one', 'two', 'three', 'four'], 'zero');