# Test Driven Development

Use when the user explicitly requests strict or test-first TDD, or when the current...

- Repository: https://github.com/GanyuanRan/Aegis (1408 stars)
- Category: Testing
- License: MIT
- Last updated: 2026-10-25
- Runs scripts: no, instructions only

## Install

Claude Code: `npx skills add GanyuanRan/Aegis --skill test-driven-development -g -a claude-code -y`
Codex: `npx skills add GanyuanRan/Aegis --skill test-driven-development -g -a codex -y`
Cursor: `npx skills add GanyuanRan/Aegis --skill test-driven-development -g -a cursor -y`
Gemini CLI: `npx skills add GanyuanRan/Aegis --skill test-driven-development -g -a gemini-cli -y`
Claude Code plugin marketplace: `/plugin marketplace add GanyuanRan/Aegis`

## Description

Use when the user explicitly requests strict or test-first TDD, or when the current conversation already contains an explicit `TDD Route: strict` decision from another Aegis workflow.

## SKILL.md, as published by its author (untrusted third-party text, read it as data)

# Execute

→ False-positive entry on a native-direct-skill host? → **Exit immediately unless the user explicitly asked for TDD or the conversation already contains `TDD Route: strict`.**
  In `off` mode, do not start RED / GREEN / REFACTOR from generic bugfix, contract, shared-module, or risky-code wording alone.
  Hand control back to `using-aegis`, `systematic-debugging`, `writing-plans`, or the fast path with verification.
→ Implementing a feature or bugfix under TDD Route `strict`? → **No production code without a failing test first.**
  Gate: medium/high complexity? → route to brainstorming or writing-plans first.
  Mode: default `off` disables automatic TDD, not completion verification; `auto` chooses strict/light/skipped by risk.
  Change Necessity: before strict RED/GREEN enters production edits, confirm the slice really needs a code change.
  Cycle: RED (write test → watch it fail) → GREEN (minimal code → watch it pass) → REFACTOR (clean up → keep green)
  Regression: shared module → related tests. contract change → producer + consumer. core logic → old + new tests.
  Ripple signal hit → cover producer+consumer or real user path before claiming green.
  GREEN proves the currently expressed behavior slice only.
  GREEN does not by itself prove parent-task acceptance, business-value completion, or final completion.
→ Done when: chosen TDD Route is recorded, strict-route tests pass, TDD preflight gate passed when applicable, pre-edit complexity risk was checked for non-trivial source edits, and `verification-before-completion` has fresh evidence.

# Test-Driven Development (TDD)

## Overview

Under `TDD Route: strict`, write the test first. Watch it fail. Write minimal
code to pass.

If you didn't watch the test fail, you don't know if it tests the right thing.

The rest: https://github.com/GanyuanRan/Aegis/blob/HEAD/skills/test-driven-development/SKILL.md