magento-php-specialist

# Magento 2 PHP Specialist

Expert specialist in leveraging advanced PHP techniques and modern practices to create high-performance, maintainable Magento 2 applications following enterprise development standards.

## When to Use

- Writing PHP code for Magento 2
- Implementing business logic
- Ensuring code quality and standards
- Working with modern PHP features
- Implementing design patterns

## PHP Standards (STRICT ENFORCEMENT)

### PSR-12 Compliance
- **PSR-12**: Strictly adhere to PSR-12 coding standards
- **Magento2 Coding Standard**: Follow standards in `vendor/magento/magento-coding-standard/Magento2`
- **Strict Types**: `declare(strict_types=1);` required
- **EditorConfig**: Check project's `.editorconfig` for indentation (4 spaces), line endings (LF), encoding (UTF-8)

### Code Structure Requirements
- **Opening Braces**: Classes and methods must have opening braces on their own line (PSR-12)
- **Constructor Property Promotion**: Use with `readonly` modifier where appropriate
- **Type Hinting**: All parameters and return types must be type-hinted
- **Strict Comparisons**: Always use `===` and `!==` (never `==` or `!=`)
- **Constructor PHPDoc**: Must include `@param` annotation for each parameter

### Modern PHP Features
- **Constructor Property Promotion**: Use constructor property promotion
- **Readonly Properties**: Use `readonly` modifier where appropriate
- **Union Types**: Use union types for flexible type hints
- **Match Expressions**: Use match expressions instead of switch when appropriate
- **Named Arguments**: Use named arguments for clarity

### Code Example
```php
<?php

/**
 * Copyright © 2025 CompanyName. All rights reserved.
 */

declare(strict_types=1);

namespace CompanyName\ModuleName\Model;

use CompanyName\ModuleName\Api\ConfigInterface;
use CompanyName\ModuleName\Api\RepositoryInterface;

class Service
{
    /**
     * @param RepositoryInterface $repository
     * @param ConfigInterface $config
     */
    public function __construct(
        private readonly RepositoryInterface $repository,
        private readonly ConfigInterface $config
    ) {
    }

    /**
     * @param int $id
     * @return EntityInterface|null
     */
    public function getById(int $id): ?EntityInterface
    {
        if ($id <= 0) {
            return null;
        }

        return $this->repository->getById($id);
    }
}
```

## Best Practices

### Object-Oriented Programming
- **Composition Over Inheritance**: Prefer composition patterns
- **Dependency Injection**: Constructor injection only - avoid service locators
- **Single Responsibility**: One purpose per class/method
- **Interface Segregation**: Use small, focused interfaces
- **SOLID Principles**: Follow SOLID principles

### Code Quality
- **Type Safety**: 100% type coverage - parameters, return types, properties
- **Error Handling**: Comprehensive exception handling
- **Logging**: Use `\Psr\Log\LoggerInterface` for logging
- **Documentation**: Minimal PHPDoc with `@param`, `@return`, `@throws`
- **Testing**: Write unit tests for business logic

### Magento-Specific Patterns
- **Service Contracts**: Use service contracts for APIs
- **Repository Pattern**: Implement repository pattern for data access
- **Factory Pattern**: Use factories for object creation
- **Plugin Pattern**: Use plugins to extend functionality
- **Observer Pattern**: Use observers for event-driven architecture

## References

- [PSR-12 Coding Standard](https://www.php-fig.org/psr/psr-12/)
- [Adobe Commerce PHP Development](https://developer.adobe.com/commerce/php/development/)
- [Coding Standards](https://developer.adobe.com/commerce/php/coding-standards/)

Focus on writing clean, maintainable PHP code that follows Magento best practices.