Overview

A strict TDD enforcement inspired by the Everything Claude Code methodology. It mandates the Red-Green-Refactor cycle with evidence-based verification at each phase, including exit codes and coverage metrics.

How This Skill Works

Developers follow three phases: RED writes failing tests and records exit code 1; GREEN implements the minimal code to make tests pass with exit code 0; REFACTOR improves code quality, applies SOLID principles, reduces coupling, and re-runs tests after each change. A Coverage Gate then enforces a minimum 80% overall test coverage, iterating up to three times until met.

When to Use It

• All code implementation tasks
• Feature development
• Bug fixes (write regression test first)
• CI pipelines requiring mandatory failing tests and evidence
• Projects enforcing a measurable 80% test coverage gate

Quick Start

1. Step 1: RED Phase – write failing tests that define expected behavior; ensure tests exit code 1; use CI=true or --run; apply 60s timeout; record exit code as evidence
2. Step 2: GREEN Phase – implement the minimal code to make tests pass; ensure tests exit code 0; do not add features outside test scope; record exit code
3. Step 3: REFACTOR + Coverage – apply SOLID principles and clean patterns; improve naming and reduce duplication; run tests after each refactor; verify exit code stays 0; measure coverage and iterate up to 3 times until 80% is reached

Best Practices

• Never skip the RED phase
• Always run tests with CI=true or --run; never use watch mode in CI
• Record exit codes and coverage numbers as evidence after each phase
• In GREEN, implement only what tests cover; no extra features
• In REFACTOR, apply SOLID principles, rename for clarity, reduce coupling, and remove duplication; run tests after every refactor

Example Use Cases

• A new feature is implemented by first adding failing tests (RED), then writing the minimal code to pass (GREEN), followed by refactoring for clarity and maintainability (REFACTOR) while verifying 80%+ coverage
• A bug fix includes a regression test written first, ensuring the failure is captured, then fixed code passes tests, with refactoring to reduce duplication
• A codebase enforces an 80% coverage gate in CI, preventing merges until tests pass and coverage meets the threshold
• A refactor that improves naming and reduces coupling is followed by additional tests to cover edge cases, maintaining exit code 0 across all phases
• SOLID-compliant refactoring after tests pass, validated by coverage metrics and repeated test runs

Frequently Asked Questions