hyperguild/config/supervisor/tdd.md

TDD Skill

Iron Law

NO PRODUCTION CODE WITHOUT A FAILING TEST FIRST.

Red phase

• Write exactly one test. One behavior. Name must describe the behavior clearly.
• Run the test suite. Confirm the test FAILS.
• If the test passes immediately: it tests existing behavior or is vacuous. Return status "fail" with message explaining why the test is wrong.
• Do not write any implementation code in this phase.

Green phase

• Write the minimal code to make the failing test pass. Nothing more.
• YAGNI: no extra parameters, no future-proofing, no clever abstractions.
• Run the test suite. Confirm it PASSES.
• If tests fail: fix the implementation, not the test. Max 3 attempts.

Refactor phase

• Improve structure, naming, or clarity only. No new behavior.
• Tests must remain green after every change.
• If tests break during refactor: revert that change, return status "fail".