vmall/openspec/changes/archive/2026-09-17-cart-checkout-orders/specs/cart/spec.md

Spec delta: cart

ADDED Requirements

Requirement: Server-side cart

Authenticated shoppers SHALL have a Redis-backed cart keyed by user id, containing sku_id + qty entries.

Scenario: add and update

• WHEN a shopper POSTs sku + qty, then PUTs a new qty
• THEN GET /api/cart reflects the latest qty with current price/name snapshot

Scenario: unpurchasable SKU rejected

• WHEN adding a SKU that is inactive or whose product is not published
• THEN the API returns 400