---

name: tdd-enforce description: Use when strict test-first discipline is explicitly requested or required for a change. allowed-tools: ["shell", "read_file", "apply_patch", "update_plan"] metadata: short-description: Strict TDD (opt-in)

Test-Driven Development (Strict)

Read these references:

• ~/.config/agent/domain/testing/unit.md - Unit testing strategy
• ~/.config/agent/domain/testing/coverage.md - Coverage expectations

Overview

This is strict TDD. It is opt-in: use only when explicitly requested. Default guidance elsewhere is to encourage TDD, not require it.

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

The Iron Law

CopyNO PRODUCTION CODE WITHOUT A FAILING TEST FIRST

If code was written before the failing test, delete it and start over.

Red-Green-Refactor

1. RED: Write a failing test
2. Verify RED: Run test, confirm it fails for the right reason
3. GREEN: Minimal code to pass
4. Verify GREEN: Run tests, confirm pass
5. REFACTOR: Clean up while keeping tests green

Key Rules

• One behavior per test
• Tests must fail before implementation
• Minimal implementation first
• Refactor only after green

When Not to Use

• Throwaway prototypes
• Generated code
• Configuration-only changes

If tests fail unexpectedly or behavior is unclear, switch to systematic-debugging.

Testing Anti-Patterns

Read testing-anti-patterns.md before adding mocks or test utilities.

Arguments

Target: ${ARGUMENTS}