tdd

TDD Command

This command enforces a test-driven development methodology directly.

What This Command Does

1. Scaffold Interfaces - Define types/interfaces first
2. Generate Tests First - Write failing tests (RED)
3. Implement Minimal Code - Write just enough to pass (GREEN)
4. Refactor - Improve code while keeping tests green (REFACTOR)
5. Verify Coverage - Ensure 80%+ test coverage

When to Use

Use /tdd when:

• Implementing new features
• Adding new functions/components
• Fixing bugs (write test that reproduces bug first)
• Refactoring existing code
• Building critical business logic

How It Works

This command should:

1. Define interfaces for inputs/outputs
2. Write tests that will FAIL (because code doesn't exist yet)
3. Run tests and verify they fail for the right reason
4. Write minimal implementation to make tests pass
5. Run tests and verify they pass
6. Refactor code while keeping tests green
7. Check coverage and add more tests if below 80%

TDD Cycle

RED → GREEN → REFACTOR → REPEAT

RED:      Write a failing test
GREEN:    Write minimal code to pass
REFACTOR: Improve code, keep tests passing
REPEAT:   Next feature/scenario

Example Usage

User: /tdd I need a function to calculate market liquidity score

Assistant:
# TDD Session: Market Liquidity Score Calculator

## Step 1: Define Interface (SCAFFOLD)

```python
# lib/liquidity.py
from dataclasses import dataclass
from datetime import datetime
from typing import NotRequired

@dataclass
class MarketData:
    totalVolume: float
    bidAskSpread: float
    activeTraders: int
    lastTradeTime: datetime

def calculateLiquidityScore(market: MarketData) -> float:
    # TODO: Implementation
    raise NotImplementedError('Not implemented')

Step 2: Write Failing Test (RED)

# tests/test_liquidity.py
import pytest
from lib.liquidity import calculateLiquidityScore, MarketData
from datetime import datetime

def test_liquid_market_high_score():
    """Test that liquid market gets high score."""
    market = MarketData(
        totalVolume=100000,
        bidAskSpread=0.01,
        activeTraders=500,
        lastTradeTime=datetime.now()
    )