tdd

name: tdd description: TDD (Test-Driven Development) workflow. Use when writing tests, implementing features with TDD, or when user says "go" to proceed with plan.md allowed-tools: Read, Write, Edit, Bash, Grep, Glob

TDD Workflow

Follow Kent Beck's TDD cycle: Red → Green → Refactor

Cycle

1. Red: Write the simplest failing test first
2. Green: Implement minimum code to make tests pass
3. Refactor: Improve structure only after tests pass

Test Writing

• Use meaningful names describing behavior (e.g., shouldSumTwoPositiveNumbers)
• Make failures clear and informative
• Write one test at a time

Implementation

• Write just enough code to pass - no more
• Use the simplest solution that could possibly work
• Run all tests after each change

Defect Fixing

1. Write an API-level failing test first
2. Write the smallest test replicating the problem
3. Get both tests to pass

Refactoring Phase

• Only refactor when tests are passing (Green phase)
• Use established patterns with proper names
• Make one change at a time
• Run tests after each step
• Prioritize removing duplication and improving clarity

Example Workflow

1. Write a simple failing test for a small part of the feature
2. Implement bare minimum to pass
3. Run tests to confirm (Green)
4. Use tidy-first skill for structural changes
5. Use commit skill for committing
6. Add another test for next increment
7. Repeat until complete