Why is immutability important in PHP DDD?

Immutability ensures that Value Objects and Events remain unchanged after creation, which prevents accidental side effects, ensures thread safety, and maintains domain invariants throughout the application lifecycle.

How does it help with refactoring?

The skill generates an Immutability Analysis Report that identifies the exact file and line of a violation, provides the 'Bad' code snippet, and shows the 'Expected' immutable version for quick correction.

What specific object types does the analyzer target?

It primarily targets Value Objects, Domain Events, Data Transfer Objects (DTOs), and Read Models, using both file path patterns and structural code analysis.

Can it detect mutations within collections and arrays?

Yes, the skill includes detection patterns for array mutations such as array_push, unset, and direct index assignments within classes that are intended to be immutable.

Does this skill support the latest PHP features?

Yes, it specifically checks for and encourages the use of 'readonly' classes and properties introduced in PHP 8.2, which is the modern best practice for immutable objects.

PHP Immutability Analyzer

Name: PHP Immutability Analyzer
Author: dykyi-roman

bydykyi-roman

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セキュリティとテスト

Analyzes PHP code for immutability violations in Value Objects, Events, and DTOs to ensure architectural integrity.

The PHP Immutability Analyzer is a specialized diagnostic tool designed for projects utilizing Domain-Driven Design (DDD), Hexagonal, or Clean Architecture. It automatically scans your codebase to identify architectural anti-patterns, such as missing readonly keywords, unauthorized setters, and the use of mutable DateTime objects. By enforcing strict immutability for Value Objects, Domain Events, and DTOs, this skill helps developers maintain thread safety and predictable state, providing a comprehensive compliance report with actionable refactoring recommendations aligned with modern PHP 8.2+ standards.

主な機能

0145 GitHub stars

02Flagging of mutable DateTime usage in favor of DateTimeImmutable

03Validates 'wither' pattern implementation for state transitions

04Identifies illegal setter methods and state mutations outside of constructors

05Generates detailed compliance reports with architectural health scores

06Detects missing 'readonly' and 'final' modifiers on immutable domain components

ユースケース

01Auditing legacy PHP applications for DDD compliance during architectural refactoring

02Upgrading existing codebases to leverage PHP 8.2+ readonly class features

03Automating code reviews to ensure new Domain Events and Value Objects are strictly immutable

What are Skills?·How to Install

Install with 🐟 Skill.Fish

npx skillfish add dykyi-roman/awesome-claude-code check-immutability

For use in Claude.ai and ChatGPT

Download Skill