E2E Tests for Shopping Cart and Checkout

Problem/Feature Description

An e-commerce web application needs E2E tests for its shopping cart and checkout flow. Write Cypress tests for adding products to the cart, updating quantities, and completing checkout.

The app runs on http://localhost:3000 with these pages:

• /products -- product listing with "Add to cart" buttons on each product card
• /cart -- cart page showing items, quantities, subtotals, and a "Proceed to checkout" button
• /checkout -- checkout form with shipping address fields, payment section, and "Place order" button
• /orders/:id -- order confirmation page

The app has these API endpoints:

• GET /api/products -- returns product list
• POST /api/cart/items -- adds item to cart
• PATCH /api/cart/items/:id -- updates item quantity
• DELETE /api/cart/items/:id -- removes item from cart
• GET /api/cart -- returns current cart contents
• POST /api/orders -- creates an order from the cart

Output Specification

Produce:

• cypress.config.ts -- Cypress configuration
• cypress/e2e/cart.cy.ts -- tests for cart operations (add, update quantity, remove)
• cypress/e2e/checkout.cy.ts -- tests for the checkout flow and form validation
• cypress/support/commands.ts -- any reusable test helpers
• cypress/fixtures/products.json -- fixture data for product API responses
• package.json -- with cypress dependency listed

You may create additional files for good test organization.