check-encapsulation

Encapsulation Analyzer

Overview

This skill analyzes PHP codebases for encapsulation violations — situations where internal state is exposed, getters/setters replace behavior, or the "Tell, Don't Ask" principle is violated.

When to Use

• Reviewing Domain layer entities and aggregates
• Detecting anemic domain models
• Checking for Law of Demeter violations
• Auditing collection exposure patterns
• Evaluating getter/behavior ratio in entities

Encapsulation Principles

Principle	Description	Violation Indicator
Information Hiding	Internal state not exposed	Public properties, many getters
Tell Don't Ask	Objects perform actions, not expose data	Getter chains, external decisions
Behavioral Richness	Objects have behavior, not just data	Anemic domain model
Invariant Protection	State changes validate constraints	Public setters without validation

Analysis Approach

1. Phase 1 — Public Mutable State: Scan Domain entities for non-readonly public properties
2. Phase 2 — Getter/Setter Abuse: Count getters vs behavior methods, flag anemic entities
3. Phase 3 — Tell Don't Ask: Detect getter chains and external conditionals on object state
4. Phase 4 — Collection Exposure: Find methods returning internal arrays/collections directly
5. Phase 5 — Exposed Internals: Check for reflection usage, debug methods, mutable object returns
6. Phase 6 — Constructor Issues: Flag too many dependencies, complex construction without factories

Detection Rules

ID	Pattern	Grep Target
ENC-01	Public mutable props	public string|public int|public array in Domain (exclude readonly)
ENC-02	Setter methods	public function set[A-Z] in Entity/Aggregate
ENC-03	Getter chains	->get[A-Z].*->get[A-Z].*->get[A-Z]
ENC-04	External conditionals	if \(\$.*->get[A-Z].*===
ENC-05	Switch on state	switch \(\$.*->get[A-Z]|match \(\$.*->get[A-Z]
ENC-06	Collection return	public function get.*\(\): array in Entity
ENC-07	Doctrine exposure	public function get.*\(\): Collection in Domain
ENC-08	Reflection access	ReflectionClass|ReflectionProperty|setAccessible
ENC-09	Debug exposure	public function toArray\(\)|dump\(\)|debug\(\) in Domain
ENC-10	Complex construction	new [A-Z].*Entity\(|new [A-Z].*Aggregate\( in Application

Severity Classification

Issue	Severity
Public mutable state in Entity	Critical
Collection mutated externally	Critical
Anemic entity (ratio > 5.0)	Critical
Tell Don't Ask violation	Major
Getter chain (3+ levels)	Major
Internal array returned	Major
Setter in Aggregate	Minor
Reflection in non-test code	Minor

Report Format

# Encapsulation Analysis Report

## Summary

| Issue Type | Critical | Warning | Info |
|------------|----------|---------|------|
| Public Mutable State | N | N | - |
| Getter/Setter Abuse | N | N | N |
| Tell Don't Ask | N | N | - |
| Collection Exposure | N | N | - |
| Exposed Internals | N | N | N |

**Encapsulation Score: X%**

## Findings

### [ID]: [Title]
- **File:** `path:line`
- **Issue:** [Description]
- **Code:** [Problematic snippet]
- **Expected:** [Correct pattern]
- **Skills:** [Related generator skills]

## Getter/Behavior Ratio

| Entity | Getters | Setters | Behavior | Ratio | Status |
|--------|---------|---------|----------|-------|--------|

**Target:** Ratio < 2.0

## Refactoring Recommendations

### Immediate
1. Make all entity properties private
2. Replace setters with behavior methods
3. Return collection copies, not references

### Short-term
4. Extract Value Objects for validated data
5. Add factory methods for complex construction
6. Remove getter chains (add shortcut methods)

### Long-term
7. Review anemic entities for missing behavior
8. Consider CQRS to separate read/write models

Integration

Works with:

• detect-code-smells — Feature Envy, Anemic Model
• structural-auditor — DDD compliance
• create-entity — Generate rich entities
• create-value-object — Encapsulated value types

References

• references/patterns.md — detailed detection patterns with code examples, report format samples, metrics examples, and rich entity template
• "Tell, Don't Ask" — Martin Fowler
• "Anemic Domain Model" — Martin Fowler
• "Object-Oriented Software Construction" (Bertrand Meyer)
• "Elegant Objects" (Yegor Bugayenko)