# Spec Delta

## MODIFIED Requirements

### Requirement: Shopping flow
A shopper SHALL be able to browse, view detail, add to cart, checkout with a shipping address, pay, track orders/shipments, confirm delivery, and request an invoice against the live API. Cart, order, shipment and invoice state SHALL be the backend's rather than the browser's, and the fixed-data adapter SHALL remain available as a configured fallback rather than the default. Adding to the cart SHALL require an authenticated shopper: an anonymous add SHALL send the shopper to sign in and return them to where they left off.

#### Scenario: end-to-end purchase
- **WHEN** a shopper completes checkout on a non-empty cart
- **THEN** the resulting order appears in the buyer center and the cart is empty

#### Scenario: anonymous add prompts sign-in
- **WHEN** a signed-out shopper adds an in-stock SKU from a product page
- **THEN** they are sent to sign in and, once signed in, returned to that product page

### Requirement: Mock transaction flow
The mall SHALL provide a store-grouped cart, address-selecting checkout preview, payment selection and payment-success result, all reading and writing the live cart and order APIs. Quantity changes, removals, selection totals, checkout and payment SHALL be persisted by the backend for the signed-in shopper, so they survive a page reload.

#### Scenario: complete mock purchase
- **WHEN** a shopper adds an in-stock SKU, checks out with a mock address and confirms a payment
- **THEN** the cart is cleared, the success page is shown and the new order appears in the user order list

#### Scenario: cart survives a reload
- **WHEN** a signed-in shopper adds an item and then reloads the page
- **THEN** the cart still holds that item, priced and stocked from the catalog