* Test the system by adding products in negative quantities, along with other products, to balance the total. * Try to add more of a product than is available. * Check if a product in your wishlist or cart can be moved to another user's cart or removed from it.
Source: Business Logic Errors/README.md in PayloadsAllTheThings. From PayloadsAllTheThings by Swissky and contributors. MIT License, Copyright (c) 2019 Swissky.