45ck immutability-opportunity-finder
Purpose
Identify where value objects, read-only state, or immutable design would reduce bugs and simplify reasoning.
Trigger this skill when
- Mutation bugs or reasoning difficulty are high.
- Some classes behave like value objects.
- Thread safety or caching would benefit from immutability.
Expected inputs
- class definitions
- mutation behavior
- threading assumptions
- equality semantics
- performance constraints
Deliverables
- immutability candidates
- benefits and costs
- value-object opportunities
- mutation hot spots
- recommended changes
Operating procedure
- Identify the object-oriented concern this skill is meant to assess.
- Separate facts from inferred design intent.
- Review the current structure against OOP fundamentals: responsibility, invariants, ownership, exposure, abstraction, and lifecycle where relevant.
- Surface concrete risks, tradeoffs, and improvement options.
- Prefer minimal structural change that materially improves clarity or safety.
- Hand off to the next most relevant skill if the issue is broader than this skill alone can resolve.
Quality gates
- Findings are tied to concrete code structure or stated design intent.
- Recommendations explain why, not just what.
- Tradeoffs are stated when multiple designs could work.
- Output avoids style nitpicks unless they affect abstraction or maintainability.
Handoff targets
- constructor-sanity-checker
- equals-hashcode-reviewer
- object-lifecycle-reviewer
Output style
- Be explicit about uncertainty.
- Prefer short, evidence-based findings over long vague critique.
- Distinguish design defects from mere preference.
- End with recommended next actions.
Failure modes to avoid
- Do not invent framework constraints without evidence.
- Do not recommend sweeping refactors without naming the benefit.
- Do not confuse naming/style issues with true design problems unless they affect abstraction.
- Do not force inheritance, immutability, or statics as ideology.
Minimum output skeleton
## Summary
## Findings
## Risks
## Recommendations
## Tradeoffs
## Recommended next skill