[5.6] Add ability to seed Arr::shuffle()

src/Illuminate/Support/Arr.php

@@ -541,11 +541,20 @@ public static function set(&$array, $key, $value)
      * Shuffle the given array and return the result.
      *
      * @param  array  $array
+     * @param  int|null  $seed
      * @return array
      */
-    public static function shuffle($array)
+    public static function shuffle($array, $seed = null)
     {
-        shuffle($array);
+        if (is_null($seed)) {
+            shuffle($array);
+        } else {
+            srand($seed);
+
+            usort($array, function () {
+                return rand(-1, 1);
+            });
+        }
 
         return $array;
     }

src/Illuminate/Support/Collection.php

@@ -1360,19 +1360,7 @@ public function shift()
      */
     public function shuffle($seed = null)
     {
-        $items = $this->items;
-
-        if (is_null($seed)) {
-            shuffle($items);
-        } else {
-            srand($seed);
-
-            usort($items, function () {
-                return rand(-1, 1);
-            });
-        }
-
-        return new static($items);
+        return new static(Arr::shuffle($this->items, $seed));
     }
 
     /**

tests/Support/SupportArrTest.php

@@ -498,6 +498,14 @@ public function testSet()
         $this->assertEquals(['products' => ['desk' => ['price' => 200]]], $array);
     }
 
+    public function testShuffleWithSeed()
+    {
+        $this->assertEquals(
+            Arr::shuffle(range(0, 100, 10), 1234),
+            Arr::shuffle(range(0, 100, 10), 1234)
+        );
+    }
+
     public function testSort()
     {
         $unsorted = [