check-immutability

Installation
SKILL.md

Immutability Analyzer

Overview

This skill analyzes PHP DDD projects for immutability violations in Value Objects, Domain Events, DTOs, and Read Models. Immutability is crucial for maintaining invariants, thread safety, and predictable behavior.

Immutability Requirements by Type

Type Must Be Immutable Key Checks
Value Object ✅ Required readonly, no setters, final
Domain Event ✅ Required readonly, no modification after creation
DTO ✅ Recommended readonly, no business logic
Read Model ✅ Required readonly, projection-only changes
Entity ⚠️ Controlled Setters via behavior methods only
Aggregate ⚠️ Controlled State changes via domain methods

Detection Patterns

Related skills
Installs
5
GitHub Stars
71
First Seen
Mar 17, 2026