Корзина

Когда использовать

Implement a cart with explicit quantity and money invariants.

Решения для реализации

1. Use integer minor currency units and a currency code.
2. Key lines by product and variant; quantities must be bounded positive integers.
3. Validate persisted storage and handle unavailable localStorage. Device-local state is not server persistence.
4. Reprice and validate inventory on the server before an order.

Как проверить результат

• Repeat additions merge the same variant.
• Invalid storage cannot crash the UI.
• Removing the last line yields a usable empty state.

Работающий пример

Файлы