with cast tests

tests/Casters/SimpleValueCaster.php

@@ -0,0 +1,20 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Tests\Casters;
+
+class SimpleValueCaster
+{
+    public function cast(mixed $value): SimpleValue
+    {
+        return new SimpleValue($value['value'] * 2);
+    }
+
+    public static function rules(): array
+    {
+        return [
+            'value' => ['required', 'numeric'],
+        ];
+    }
+}