# Grey Haven Tdd Typescript > TypeScript/JavaScript Test-Driven Development with Vitest, strict red-green-refactor methodology, React component testing, and comprehensive coverage patterns. Use when implementing TypeScript features with TDD, writing Vitest tests, testing React components, developing with test-first approach, or when user mentions 'TypeScript TDD', 'Vitest', 'React testing', 'JavaScript TDD', 'red-green-refactor', 'TypeScript unit tests', or 'test-driven TypeScript'. Use when this capability is needed. - Skill: `tomevault-io/grey-haven-tdd-typescript` (Agent Skill, multi-file: 2 files) - Install (CLI): `npx skillmds@latest add tomevault-io/grey-haven-tdd-typescript` - Raw SKILL.md: https://api.skillmd.com/api/skills/tomevault-io/grey-haven-tdd-typescript/raw - Safety review: pending (external: skill-scanner PASS, skillspector PASS) - Works with: Claude Code, Claude.ai, OpenAI Codex - Category: Web & Frontend - Author: tomevault-io (https://skillmd.com/u/tomevault-io) - Updated: 2026-09-17 - Page: https://skillmd.com/skills/tomevault-io/grey-haven-tdd-typescript --- # TDD TypeScript Skill Expert TypeScript/JavaScript TDD implementation using strict red-green-refactor methodology with Vitest testing framework. ## Description Implement features by writing failing tests first, minimal code to pass, then refactoring. Comprehensive TypeScript/React TDD patterns. ## What's Included - **Examples**: TDD cycles, React component TDD, utility function TDD - **Reference**: Red-green-refactor patterns, Vitest best practices - **Templates**: Test templates, implementation workflows ## Use When - Implementing TypeScript features with TDD - React component development - Ensuring high test coverage ## Related Agents - `tdd-typescript-implementer` **Skill Version**: 1.0 --- > Converted and distributed by [TomeVault](https://tomevault.io/claim/greyhaven-ai) — claim your Tome and manage your conversions.