approvalsTypescript

Enforce and guide the Mikado Method when a developer is refactoring, restructuring, or dealing with legacy code. Use this skill whenever the user mentions refactoring, technical debt, legacy code, code restructuring, dependency untangling, or "breaking everything" when making changes. Also trigger when the user wants to make a large change safely, asks how to split a big refactoring task, wants to work on main branch without a long-lived feature branch, or asks how to incrementally improve a codebase. The skill enforces the full Mikado loop: goal → naive attempt → map prerequisites → revert → implement leaves → commit → repeat.

Evaluate TypeScript/JavaScript code against Dave Thomas's OO principles and the Tell Don't Ask rule. Trigger when: class has only static methods; class has a single public method + constructor; code uses GoF pattern names (Decorator/Factory/Strategy/Builder/Command/Observer); class is invalid until setters are called; data class with only constructor + properties; external code reads getters to make decisions (Tell Don't Ask); user asks "is this a code smell?", "should this be a class or a function?", or "why does my code feel procedural?".

Detect code smells and apply refactoring techniques to improve clarity, testability, and maintainability.

Guide users through TDD and TCRDD (Test && Commit || Revert + Test Driven Development). Use this skill whenever a user mentions TDD, test-driven development, writing tests before code, red-green-refactor cycles, or unit testing workflows. Also trigger when a user asks about TCRDD, TCR, "test commit revert", "git gamble", or wants a strict TDD workflow with automatic commits and reverts. Trigger when the user asks to implement a feature, fix a bug, or write a class/function and mentions tests, TDD, or "test first". If the user shares code and asks for a review with any testing angle, consult this skill.

Master testing strategy — philosophy, approach, architecture decisions, test quality audit, and BDD review practices.

Design patterns for TypeScript—Factory, Strategy, Builder, Decorator, Singleton, Mixin, and more with problem-oriented and GoF triggers.

TypeScript error handling via union returns, strictness policy, runtime validation with Zod, monorepo contracts, and domain types vs DTOs.

SOLID principles for reducing coupling and improving testability—SRP, OCP, LSP, ISP, and DIP with TypeScript examples.

Deep dive into TypeScript's type system—narrowing, discriminated unions, mapped types, conditional types, type guards, branding, and escape hatches.