NEW Adding a shuffle method to ArrayList (#8984)

* NEW Adding a shuffle method to ArrayList

* API Add shuffle to DataList for ArrayList parity

src/ORM/ArrayList.php

@@ -572,6 +572,18 @@ class ArrayList extends ViewableData implements SS_List, Filterable, Sortable, L
         return $list;
     }
 
+    /**
+     * Shuffle the items in this array list
+     *
+     * @return $this
+     */
+    public function shuffle()
+    {
+        shuffle($this->items);
+
+        return $this;
+    }
+
     /**
      * Returns true if the given column can be used to filter the records.
      *

src/ORM/DataList.php

@@ -1133,6 +1133,16 @@ class DataList extends ViewableData implements SS_List, Filterable, Sortable, Li
         return $this;
     }
 
+    /**
+     * Shuffle the datalist using a random function provided by the SQL engine
+     *
+     * @return $this
+     */
+    public function shuffle()
+    {
+        return $this->sort(DB::get_conn()->random());
+    }
+
     /**
      * Remove every element in this DataList.
      *

tests/php/ORM/ArrayListTest.php

@@ -1236,4 +1236,19 @@ class ArrayListTest extends SapphireTest
         $list->setDataClass(DataObject::class);
         $this->assertEquals(DataObject::class, $list->dataClass());
     }
+
+    public function testShuffle()
+    {
+        $upperLimit = 50;
+
+        $list = new ArrayList(range(1, $upperLimit));
+
+        $list->shuffle();
+
+        for ($i = 1; $i <= $upperLimit; $i++) {
+            $this->assertContains($i, $list);
+        }
+
+        $this->assertNotEquals(range(1, $upperLimit), $list->toArray());
+    }
 }

tests/php/ORM/DataListTest.php

@@ -1837,4 +1837,11 @@ class DataListTest extends SapphireTest
             $list->column("Title")
         );
     }
+
+    public function testShuffle()
+    {
+        $list = Team::get()->shuffle();
+
+        $this->assertSQLContains(DB::get_conn()->random() . ' AS "_SortColumn', $list->dataQuery()->sql());
+    }
 }