Automating PHP Refactoring with Rector

Keeping code clean and updated is important in software development, but refactoring can take a lot of time, especially in big projects. PHP Rector is a tool that helps automate these changes, making sure your code follows best practices and modern PHP standards.

What is PHP Rector?

Rector is a tool that automatically updates and improves PHP code based on predefined rules. it Can:

• Upgrade PHP versions.
• Apply coding standards automatically.
• Remove old and unnecessary code.
• Replace outdated function or method calls.
• Add type hints to properties, function parameters, and return values.
• Convert old docblocks into modern attributes.

Installation

You can install Rector using composer:
composer require --dev rector/rector

Configs

To configure Rector, create a rector.php file in your project's root folder:

declare(strict_types=1);

use Rector\Config\RectorConfig;
use Rector\Php74\Rector\Property\TypedPropertyRector;
use Rector\Php80\Rector\Class_\DoctrineAnnotationToAttributeRector;
use Rector\Php81\Rector\Class_\SpreadingVariadicArgumentsRector;

return static function (RectorConfig $rectorConfig): void {
    $rectorConfig->rule(TypedPropertyRector::class);
    $rectorConfig->rule(DoctrineAnnotationToAttributeRector::class);
    $rectorConfig->rule(SpreadingVariadicArgumentsRector::class);
};

This example enables:

• Typed properties (PHP 7.4+).
• Conversion of Doctrine annotations to attributes (PHP 8+).
• Modern variadic argument syntax (PHP 8.1+).

Running Rector

To apply Rector to your code, run:
vendor/bin/rector process src

This will analyze and update the code inside the src folder.

Examples

Adding Type Hints to Properties

Before:

class User {
    /** @var string */
    private $name;
}

After:

class User {
    private string $name;
}

Converting Annotations to Attributes

Before:

/**
 * @ORM\Entity()
 * @ORM\Table(name="users")
 */
class User {
    /** @ORM\Id */
    /** @ORM\GeneratedValue */
    /** @ORM\Column(type="integer") */
    private $id;
}

After:

use Doctrine\ORM\Mapping as ORM;

#[ORM\Entity]
#[ORM\Table(name: "users")]
class User {
    #[ORM\Id]
    #[ORM\GeneratedValue]
    #[ORM\Column(type: "integer")]
    private int $id;
}

Updating Variadic Argument Syntax

Before:

function sum(...$numbers) {
    return array_sum($numbers);
}

$values = [1, 2, 3];
echo sum(...$values);

After:

function sum(int ...$numbers): int {
    return array_sum($numbers);
}

$values = [1, 2, 3];
echo sum(...$values);

Conclusion

PHP Rector is a great tool for keeping your code clean and updated with less manual work. You can also add it to a CI/CD pipeline to make sure your project follows best practices automatically.

Do you use Rector in your projects? Share your experience in the comments!