# Shared Tdd

> TDD policy — red-green-refactor workflow and evidence requirements for all platforms.

- Skill: `majiayu000/shared-tdd` (Agent Skill, multi-file: 2 files)
- Install (CLI): `npx skillmds add majiayu000/shared-tdd`
- Raw SKILL.md: https://api.skillmd.com/api/skills/majiayu000/shared-tdd/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Productivity
- Author: majiayu000 (https://skillmd.com/u/majiayu000)
- Updated: 2026-09-09
- Page: https://skillmd.com/skills/majiayu000/shared-tdd

---


## Purpose

Mandate test-driven development across all platforms. Platform coding standards reference this for the TDD workflow, then add platform-specific test tooling and conventions.

## TDD workflow (mandatory)

For any new behavior or bug fix:

1. **Red** — Write failing test(s) first
   - Derive test cases from acceptance criteria
   - Run tests to confirm failure
   - Do NOT write implementation code yet

2. **Green** — Write minimum code to pass
   - No feature creep beyond test requirements
   - Run tests after each change

3. **Refactor** — Clean up while tests stay green
   - Improve code quality without changing behavior

## Bug fixes

Bug fixes require a failing test that reproduces the issue *before* the fix is written.

## Completion gate

Stories cannot be marked complete without test files. Test files must exist before marking a story done.

## TDD evidence

When implementing features, document in commit or PR:
- Which tests were written first
- Confirmation that tests failed before implementation