Initial commit

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01F22Ms5Cxam5UHyxaCrtZzu

lib/cart-handlers.ts

@@ -0,0 +1,43 @@
+import { createCartServerHandlers, gql } from "@shopify/hydrogen";
+
+/**
+ * Custom cart fragment — adds `updatedAt` (for analytics cart-change dedupe)
+ * and `merchandise.price`/`product.id`/`product.vendor` (required by the
+ * `AnalyticsCart` shape the analytics bus consumes). Composed alongside the
+ * built-in `HydrogenCartFragment` by `createCartServerHandlers`.
+ *
+ * `hydrogen-analytics`: `updateCart()` keys dedupe on `updatedAt`; without it
+ * cart events are silently ignored. The bus's `AnalyticsCartLine` requires
+ * `merchandise.price` and `product.{id,vendor}`, which the default fragment
+ * omits.
+ */
+const cartFragment = gql(`
+  fragment CartFragment on Cart {
+    updatedAt
+    lines(first: 250) {
+      nodes {
+        merchandise {
+          ... on ProductVariant {
+            price {
+              amount
+              currencyCode
+            }
+          }
+        }
+      }
+    }
+  }
+`);
+
+/**
+ * Cart server handlers, registered in the root middleware's
+ * `handleShopifyRoutes` wiring. The React cart bindings in `app/lib/cart.ts`
+ * are derived from these handlers' type so the cart provider's `initialData`
+ * envelope and line types stay in sync with the server contract.
+ *
+ * `hydrogen-request-handlers` / `references/frameworks.md` owns the wiring; the
+ * `hydrogen-cart-ui` React reference owns the provider/form helpers.
+ */
+export const cartHandlers = createCartServerHandlers({
+  fragment: cartFragment,
+});