# Tdd Workflow

> TDD London School workflow -- mock-first, outside-in test development

- Skill: `majiayu000/tdd-workflow-5` (Agent Skill, multi-file: 2 files)
- Install (CLI): `npx skillmds@latest add majiayu000/tdd-workflow-5`
- Raw SKILL.md: https://api.skillmd.com/api/skills/majiayu000/tdd-workflow-5/raw
- Safety review: pending (external: skill-scanner PASS, skillspector PASS)
- 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/tdd-workflow-5

---

Follow the TDD London School (mock-first) approach:

1. **Write the failing test first** -- define expected behavior with mocked dependencies
2. **Run the test** -- confirm it fails for the right reason
3. **Implement minimal code** -- make the test pass with the simplest solution
4. **Refactor** -- clean up while keeping tests green
5. **Repeat** -- add the next behavior

Before starting: `mcp__claude-flow__hooks_pre-task({ description: "TDD: FEATURE_NAME" })`
After completing: `mcp__claude-flow__hooks_post-task({ taskId: "tdd-FEATURE", success: true, storeResults: true })`

Principles:
- Mock external dependencies at boundaries
- Test behavior, not implementation
- One assertion per test when possible
- Descriptive names: `should [behavior] when [condition]`