php-conventions

name: php-conventions description: PHP coding standards including strict typing, OOP patterns, error handling, and documentation license: MIT compatibility: opencode metadata: language: php version: "8.1+"

Strict Typing

• Always enable: declare(strict_types=1); at top of files
• Use scalar type hints: int, float, string, bool, array
• Use specific class/interface type hints
• Return type hints for ALL methods including void
• Use mixed only when necessary - document why
• Use typed properties (PHP 7.4+)

Object-Oriented Programming

• Prefer classes over procedural code
• Use final for classes not designed for extension
• Use readonly for immutable properties (PHP 8.1+)
• Use interfaces for contracts and loose coupling
• Use abstract classes for shared base functionality
• Employ Dependency Injection (constructor injection preferred)
• Avoid static methods for dependencies (except Facades used appropriately)

Error Handling

• Use Exceptions for exceptional situations only
• Create custom exception classes inheriting from SPL exceptions
• Catch specific exceptions, not base \Exception unless re-throwing
• Never use error suppression (@)
• Log errors with context using framework logging (Monolog)

Documentation

• PHPDoc blocks for all classes, properties, methods
• Include @param, @return, @throws
• Document non-obvious behavior

Code Style

<?php

declare(strict_types=1);

namespace App\Service;

use App\Repository\UserRepositoryInterface;
use App\Exception\UserNotFoundException;

final class UserService
{
    public function __construct(
        private readonly UserRepositoryInterface $user_repository
    ) {}

    /**
     * Find user by ID or throw exception.
     *
     * @throws UserNotFoundException
     */
    public function findOrFail(int $user_id): User
    {
        $user = $this->user_repository->find($user_id);
        
        if ($user === null) {
            throw new UserNotFoundException("User {$user_id} not found");
        }
        
        return $user;
    }
}

Security Checklist

• Input validated with framework tools
• SQL uses parameter binding
• Output escaped in templates
• CSRF tokens on forms
• File uploads validated and stored safely
• Dependencies audited (composer audit)