Test Driven Development

Enforces classic red-green-refactor discipline: write a failing test, watch it fail, write minimal code to pass, then clean up. The skill gates you before letting production code through without a failing test first, which sounds rigid until you realize how often "I'll add the test later" means never. It includes a preflight check that routes medium or high complexity work to planning before you start the TDD cycle, so you're not test-driving your way into the wrong architecture. Also has a pre-edit complexity check to stop you from cramming logic into an already overloaded file just because the test is green. Useful when you want the discipline enforced, not just suggested.

GitHub stars: 492
last updated: Jun 11, 2026

View on GitHub

Install

$ npx -y skills add ganyuanran/aegis --skill test-driven-development --agent claude-code

Installs into .claude/skills of the current project.

Files

Execute

False-positive entry on a native-direct-skill host? Exit immediately unless the user explicitly requested TDD or the conversation records TDD Route: strict. Return to the selecting workflow or fast path with proportional verification.
Under strict, validate preflight and Change Necessity before production edits. No production code without an observed failing behavior test first.
RED (test and observe failure) -> GREEN (minimum owner repair and observe pass) -> REFACTOR (clean up while green). Apply Regression Scope before closeout.
GREEN proves only the expressed behavior slice, not parent-task acceptance, business-value completion or final completion. Use verification-before-completion.

Entry Boundary

Enter only for an explicit strict TDD/test-first/RED / GREEN / REFACTOR request or a recorded TDD Route: strict. Native-direct-skill hosts must not infer entry from generic risky-code wording. Consume the selected route; a missing or invalid automatic decision returns to its selecting workflow.

SKILL.md on GitHub