SleepToSerializeRector

Change __sleep() to __serialize() with correct return values

 class User {
     private $id;
     private $name;

-    public function __sleep() {
-        return ['id', 'name'];
+    public function __serialize(): array {
+        return [
+            'id' => $this->id,
+            'name' => $this->name,
+        ];
     }
 }

Configure your rector.php:

<?php

use Rector\Config\RectorConfig;
use Rector\Php85\Rector\Class_\SleepToSerializeRector;

return RectorConfig::configure()
    ->withRules([
        SleepToSerializeRector::class,
    ]);
SETS:  PHP 8.5