Rules

Test Types (ALL required): 1. **Unit Tests** - Individual functions, utilities, components 2. **Integration Tests** - API endpoints, database operations 3. **E2E Tests** - Critical user flows (framework chosen per language)

> This file extends [common/testing.md](../common/testing.md) with Python specific content.

We practice strict TDD. This means: 1. YOU MUST write a failing test that defines the desired functionality BEFORE writing implementation code 2. YOU MUST run the test to confirm it fails as expected 3. YOU MUST write ONLY enough code to make the failing test pass

1. **Read & Analyze**: Read puzzle description from `data/puzzles/<day>.md` 2. **Add Example Input**: Copy example from puzzle into `data/examples/<day>.txt` 3. **Implement Part 1**: 4. **Test & Submit Part 1**:

export const add = (a, b) => a + b