pdca-code-generation-process

# PDCA Code Generation Process for E-Commerce Checkout System

## Plan Phase

**Test Cases:**
- [ ] Verify user can add items to cart
- [ ] Validate checkout process with valid payment
- [ ] Test error handling for failed payments

**Implementation Steps:**
1. Create cart service
2. Implement payment gateway integration
3. Develop order confirmation system

## Do Phase

```python
# Cart Service
class CartService:
    def __init__(self):
        self.items = []

    def add_item(self, item):
        self.items.append(item)

    def calculate_total(self):
        return sum(item.price for item in self.items)

# Payment Gateway Integration
class PaymentProcessor:
    def process_payment(self, amount, payment_details):
        # Integration with Stripe API
        if self.validate_payment(payment_details):
            return {'status': 'success', 'transaction_id': 'txn_12345'}
        return {'status': 'failed', 'error': 'Invalid payment details'}

    def validate_payment(self, payment_details):
        # Validation logic here
        return True
```

## Check Phase

**Test Results:**
- ✅ Cart service test passed
- ✅ Payment processing test passed with valid details
- ❌ Payment processing test failed with invalid details (expected behavior)

## Act Phase

**Refinements Needed:**
- Add more detailed error messages for payment validation
- Implement retry logic for failed payments
- Add unit tests for edge cases