# Test Driven Dev

> Use this skill to enforce a Test-Driven Development (TDD) workflow. It guides you through the Red-Green-Refactor cycle to ensure code correctness and testability.

- Skill: `0king0p/test-driven-dev` (Agent Skill)
- Install (CLI): `npx skillmds@latest add 0king0p/test-driven-dev`
- Raw SKILL.md: https://api.skillmd.com/api/skills/0king0p/test-driven-dev/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Productivity
- Author: 0King0P (https://skillmd.com/u/0king0p)
- Updated: 2026-09-22
- Page: https://skillmd.com/skills/0king0p/test-driven-dev

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# Skill: Test-Driven Development (TDD)

This skill provides a structured workflow for implementing features or fixing bugs using TDD principles.

## The TDD Cycle

### Phase 1: Red (Write a Failing Test)
1.  **Understand Requirements**: Identify the expected behavior.
2.  **Write Test**: Create a new test case that describes the behavior.
3.  **Run Test**: Execute the test suite. It **MUST FAIL** at this stage. This confirms the test is valid and targeting the right area.

### Phase 2: Green (Make it Pass)
1.  **Minimal Implementation**: Write the minimum amount of code required to make the test pass.
2.  **Run Test**: Execute the test suite. If it fails, fix the code and repeat until the test passes.

### Phase 3: Refactor (Clean up)
1.  **Improve Code**: Clean up the implementation (naming, structure, performance) without changing its behavior.
2.  **Run Tests**: Execute the test suite again to ensure no regressions were introduced during refactoring.

## Best Practices
- **AAA Pattern**: Organize tests into Arrange, Act, Assert sections.
- **Isolate Tests**: Ensure tests are independent and don't share state.
- **Coverage**: Aim for 100% coverage of the specific logic you are implementing.