Matt Pocock behavioral TDD

Workflow

Matt Pocock’s TDD reference emphasizes tests through agreed public interfaces, useful assertions, narrow mocking and one behavior slice at a time.

Run this command in your project after reviewing the instructions and access terms. Install complete upstream directories to keep referenced rules and scripts.

npx skills add https://github.com/mattpocock/skills/tree/5beb35b040e3de97e54fa9e386d7e42d15c295c2/skills/engineering/tdd --skill tdd --agent claude-code

Project file: .claude/skills/tdd/SKILL.md

This brief helps you choose the skill. Read the complete upstream SKILL.md and companion files for its actual instructions.

# Matt Pocock behavioral TDD (matt-pocock-tdd)
Matt Pocock’s TDD reference emphasizes tests through agreed public interfaces, useful assertions, narrow mocking and one behavior slice at a time.

## Use when
- Implement a feature or fix while protecting behavior through public interfaces.

## Required inputs
- Expected behavior and public interfaces
- Project test tools and source

## Prerequisites
- A runnable test suite and agreement on which public interfaces to test.
- Install Matt Pocock’s codebase-design skill for its referenced interface and seam vocabulary.

## Expected outputs
- Behavioral tests at agreed seams
- Incremental implementation and verification

Source: https://github.com/mattpocock/skills/blob/5beb35b040e3de97e54fa9e386d7e42d15c295c2/skills/engineering/tdd/SKILL.md
Full SKILL.md: https://agenttaste.dev/skills/matt-pocock-tdd/SKILL.md

## Popularity evidence
- 297,596 GitHub repo stars — mattpocock/skills; checked 2026-10-20. Source: https://github.com/mattpocock/skills/stargazers
- 1,114,501 skill installs (all time) — mattpocock/skills / tdd · skills.sh · all time; checked 2026-10-20. Source: https://skills.sh/mattpocock/skills/tdd
Adoption counts are not user ratings or guarantees of quality.