Try Rector Online | Rector - Automated Way to Instantly Upgrade and Refactor any PHP code

Run Rector on your code to see what it can do for you:

// no change

PHP snippet to change

<?php

final class SomeClass
{
    public function run(): void
    {
        $closure = fn ($value)  => $this->resolve($value);
    }

    private function resolve(int $value): void
    {
    }
}

Config rector.php

<?php

use Rector\Config\RectorConfig;
use Rector\TypeDeclaration\Rector\Property\TypedPropertyFromAssignsRector;
use Rector\ValueObject\PhpVersion;

return RectorConfig::configure()
    // A. whole set
    ->withPreparedSets(typeDeclarations: true);

Rector version: 3b8b78 - released at 2026-07-24 13:03