tdd

TDD — Test-Driven Development

Enforces the Red-Green-Refactor cycle for quality-driven development.

Workflow

Step 1: Understand Requirements

Use AskUserQuestion:

{
  "questions": [
    {
      "question": "What are you building with TDD?",
      "header": "Target",
      "options": [
        {"label": "New function/class", "description": "Build a new unit from scratch with tests first"},
        {"label": "New feature", "description": "Build a feature across multiple files with test coverage"},
        {"label": "Add tests to existing code", "description": "Write tests for code that already exists"},
        {"label": "Fix bug with regression test", "description": "Write a test that reproduces the bug, then fix it"}
      ],
      "multiSelect": false
    }
  ]
}

Step 2: RED — Write Failing Tests

Dispatch tdd-guide (Haiku) to:

1. Analyze the requirements
2. Identify test scenarios (happy path, edge cases, error cases)
3. Write the test file with all tests
4. Verify tests fail (RED state)

Step 3: GREEN — Implement

Dispatch executor (Sonnet) with:

• The failing test file
• Requirement to make all tests pass
• Instruction to use the simplest possible implementation
• The existing codebase context for convention matching

After implementation, run tests via Bash to verify they pass.

Step 4: REFACTOR

If tests pass, dispatch code-reviewer (Sonnet) to:

• Review the implementation for quality
• Suggest refactoring opportunities
• Verify test quality (are tests testing the right things?)

Apply refactoring suggestions, re-run tests to confirm they still pass.

Step 5: Report

## TDD Cycle Complete

### Tests Written: [N]
- ✅ Happy path: [N] tests
- ✅ Edge cases: [N] tests
- ✅ Error cases: [N] tests

### Coverage: [N]% (if measurable)

### Implementation Files
- [file:line — what was implemented]

### Refactoring Applied
- [What was improved after tests passed]