EXCEPTIONS_GUIDE.md

Custom Exceptions Guide

Usage Rules

1. Use model-specific exceptions

✅ Good:

raise UserNotFoundError(details="User not found")
raise NotificationNotFoundError(details="Notification not found")

❌ Avoid:

raise DataNotFoundError(details="User not found")  # Too generic

2. Clear and informative messages

✅ Good:

raise UserAuthenticationError(
    details="Invalid credentials. Please check your email/password."
)

3. Migration from Response

Before:

return Response({'detail': 'Error'}, status=404)

After:

raise UserNotFoundError(details="User not found")

Exceptions by Model

• Users : UserNotFoundError, UserAuthenticationError
• Products : ProductNotFoundError, ProductOutOfStockError
• Orders : OrderNotFoundError, OrderValidationError
• Categories : CategoryNotFoundError
• Notifications : NotificationNotFoundError, NotificationServiceError
• Payments : PaymentError, InsufficientFundsError