tdd

TDD Command

This command invokes the tdd-guide agent to enforce test-driven development methodology.

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 → Prove-It Pattern: 버그 재현 테스트 먼저, 수정은 그 다음
• Refactoring existing code
• Building critical business logic

Prove-It Pattern (버그 수정 전용)

BUG REPORT → REPRODUCE TEST (RED) → VERIFY FAIL → FIX (GREEN) → VERIFY PASS

버그 수정 시 "고쳤다"의 증거는 실패→성공 전환이다. 테스트 없이 수정하면 증상만 가린 것일 수 있다.

How It Works

The tdd-guide agent will:

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

Agent (tdd-guide):
# TDD Session: Market Liquidity Score Calculator

## Step 1: Define Interface (SCAFFOLD)

```typescript
// lib/liquidity.ts
export interface MarketData {
  totalVolume: number
  bidAskSpread: number
  activeTraders: number
  lastTradeTime: Date
}

export function calculateLiquidityScore(market: MarketData): number {
  // TODO: Implementation
  throw new Error('Not implemented')
}

Step 2: Write Failing Test (RED)

// lib/liquidity.test.ts
import { calculateLiquidityScore } from './liquidity'