standards-tdd

name	standards-tdd
description	Use when implementing new features, fixing bugs, or writing any production code. Enforces red-green-refactor workflow. Does not apply to documentation, configuration, or non-code file edits.
user-invocable	true
disable-model-invocation	false

TDD

Iron Law

Do not write production code without a failing test. No exceptions. If code is written before its test, delete it and start over.

Red-Green-Refactor

1. Red: Write one failing test. Verify it fails for the expected reason.
2. Green: Write minimal production code to make it pass.
3. Refactor: Refactor only after tests are green. Keep behavior unchanged.
4. Repeat for each behavior change.

Rules

• One behavior per test. Test through public interfaces only.
• Do not mock internal calls. Mock only external dependencies when unavoidable.
• Do not add production code intended only for tests.