Cart Management

[faid-terence]

Description
Why

Adding items to the cart is an essential functionality for any e-commerce website, as it allows buyers to select the items they want to purchase and proceed to checkout.

Acceptance criteria:

GIVEN that the buyer is on a product page

WHEN the buyer selects a quantity and clicks the ""Add to Cart"" button
THEN the item should be added to the buyer's cart and the buyer should see a confirmation message
GIVEN that the buyer is on a product page with an item in their cart
WHEN the buyer clicks the ""View Cart"" button or a button to view the cart without leaving the current page (optional)
THEN the buyer should be able to view their cart and the added item
Dev notes:

The form for selecting quantity should allow for positive integers only.
The ""Add to Cart"" button should be disabled if the quantity is not a positive integer.
The confirmation message should include the name and quantity of the added item.
The optional feature to view the cart without leaving the current page should be implemented using an overlay or a modal window