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name: php-modernization description: "Agent Skill: PHP 8.x modernization patterns. Use when upgrading to PHP 8.1/8.2/8.3/8.4/8.5, implementing type safety, or achieving PHPStan level 10. By Netresearch."

PHP Modernization Skill

Modernize PHP applications to PHP 8.x with type safety, PSR compliance, and static analysis.

Expertise Areas

• PHP 8.x: Constructor promotion, readonly, enums, match, attributes, union types
• PSR/PER Compliance: Active PHP-FIG standards
• Static Analysis: PHPStan (level 9+), PHPat, Rector, PHP-CS-Fixer
• Type Safety: DTOs/VOs over arrays, generics via PHPDoc

Using Reference Documentation

PHP Version Features

When implementing PHP 8.0-8.5 features (constructor promotion, readonly properties, enums, match expressions, attributes), consult references/php8-features.md.

Standards Compliance

When ensuring PSR/PER compliance or configuring PHP-CS-Fixer with @PER-CS, consult references/psr-per-compliance.md for active PHP-FIG standards.

When configuring PHPStan levels or understanding level requirements, consult references/phpstan-compliance.md for level overview and production configuration.

Static Analysis Tools

When setting up PHPStan, PHPat, Rector, or PHP-CS-Fixer, consult references/static-analysis-tools.md for configuration examples and integration patterns.

Type Safety

When implementing type-safe code or migrating from arrays to DTOs, consult references/type-safety.md for type system strategies and best practices.

When creating request DTOs or handling safe integer conversion, consult references/request-dtos.md for DTO patterns and validation approaches.

Architecture Patterns

When implementing adapter registry patterns for multiple external services, consult references/adapter-registry-pattern.md for dynamic adapter instantiation from database configuration.

When using Symfony DI, events, or modern framework patterns, consult references/symfony-patterns.md for architecture best practices.

Migration Planning

When planning PHP version upgrades or modernization projects, consult references/migration-strategies.md for assessment phases, compatibility checks, and migration workflows.

Running Scripts

Project Verification

To verify a PHP project meets modernization requirements:

Copyscripts/verify-php-project.sh /path/to/project

This script checks:

• PHPStan level compliance
• PHP-CS-Fixer configuration
• Type declaration coverage
• DTO usage patterns

Required Tools

When setting up a modernized PHP project, ensure these tools are configured:

Core Rules

DTOs Required

When passing structured data, always use DTOs instead of arrays:

Copy// Bad: public function createUser(array $data): array
// Good: public function createUser(CreateUserDTO $dto): UserDTO

Enums Required

When defining fixed value sets, always use backed enums instead of constants:

Copy// Bad: const STATUS_DRAFT = 'draft'; function setStatus(string $s)
// Good: enum Status: string { case Draft = 'draft'; }

PSR Interface Compliance

When type-hinting dependencies, use PSR interfaces (PSR-3, PSR-6, PSR-7, PSR-11, PSR-14, PSR-18).

Migration Checklist

When modernizing a PHP project, verify these requirements:

• declare(strict_types=1) in all files
• PER Coding Style via PHP-CS-Fixer (@PER-CS)
• PHPStan level 9+ (level 10 for new projects)
• PHPat architecture tests
• Return types and parameter types on all methods
• DTOs for data transfer, no array params/returns
• Backed enums for all status/type values
• Type-hint against PSR interfaces

Scoring Criteria

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Contributing: https://github.com/netresearch/php-modernization-skill