Fix bug related to readonly properties (#87)

* fix: Fix bug related to readonly properties

* feat: Skip readonly properties for PHP below 8.1

* test: Add test for readonly properties from parent scope variable

src/Serializers/Native.php

@@ -378,6 +378,10 @@ protected function mapPointers(&$data)
                         continue;
                     }
 
+                    if (PHP_VERSION >= 8.1 && $property->isReadOnly()) {
+                        continue;
+                    }
+
                     $item = $property->getValue($data);
 
                     if ($item instanceof SerializableClosure || $item instanceof UnsignedSerializableClosure || ($item instanceof SelfReference && $item->hash === $this->code['self'])) {

tests/SerializerPhp81Test.php

@@ -169,6 +169,20 @@ enum SerializerScopedBackedEnum: string {
     });
 })->with('serializers');
 
+test('readonly properties from parent scope variable', function () {
+    $controller = new SerializerPhp81Controller();
+
+    $f = static function () use ($controller) {
+        return $controller;
+    };
+
+    $f = s($f);
+
+    expect($f()->service)->toBeInstanceOf(
+        SerializerPhp81Service::class,
+    );
+})->with('serializers');
+
 test('first-class callable with closures', function () {
     $f = function ($value) {
         return $value;