SOLID principles for reducing coupling and improving testability — SRP, OCP, LSP, ISP, and DIP with annotated examples. TRIGGER when: user mentions SOLID, SRP, OCP, LSP, ISP, DIP, single responsibility principle, open-closed principle, Liskov substitution, interface segregation, dependency inversion, god class, fat interface, one reason to change, extend without modifying, depend on abstractions, interface too large, reduce coupling, improve testability.
Installation
Install with Codex or Claude Copy this prompt, paste it into Codex, Claude, or another assistant, and let it review the skill page and install it for you.
SOLID principles for reducing coupling and improving testability — SRP, OCP, LSP, ISP, and DIP with annotated examples. TRIGGER when: user mentions SOLID, SRP, OCP, LSP, ISP, DIP, single responsibility principle, open-closed principle, Liskov substitution, interface segregation, dependency inversion, god class, fat interface, one reason to change, extend without modifying, depend on abstractions, interface too large, reduce coupling, improve testability.
NEUTRAL (no regression). On the OrderService god-class all baselines already name the SRP/DIP violations, split by genuine responsibility, and — notably — do not over-split into anemic classes. The skill neither helps nor harms at this difficulty; the feared dogmatic-over-split regression did not materialise. Follow-up: author a harder borderline scenario (a class that only looks multi-purpose) to find where the skill is load-bearing. Gate per skill-optimizer/release-gates.md.
