Added framework folder

framework/bigcommerce/cart/use-cart.tsx

@@ -0,0 +1,50 @@
+import type { HookFetcher } from '@commerce/utils/types'
+import type { SwrOptions } from '@commerce/utils/use-data'
+import useCommerceCart, { CartInput } from '@commerce/cart/use-cart'
+import type { Cart } from '../api/cart'
+
+const defaultOpts = {
+  url: '/api/bigcommerce/cart',
+  method: 'GET',
+}
+
+export type { Cart }
+
+export const fetcher: HookFetcher<Cart | null, CartInput> = (
+  options,
+  { cartId },
+  fetch
+) => {
+  return cartId ? fetch({ ...defaultOpts, ...options }) : null
+}
+
+export function extendHook(
+  customFetcher: typeof fetcher,
+  swrOptions?: SwrOptions<Cart | null, CartInput>
+) {
+  const useCart = () => {
+    const response = useCommerceCart(defaultOpts, [], customFetcher, {
+      revalidateOnFocus: false,
+      ...swrOptions,
+    })
+
+    // Uses a getter to only calculate the prop when required
+    // response.data is also a getter and it's better to not trigger it early
+    Object.defineProperty(response, 'isEmpty', {
+      get() {
+        return Object.values(response.data?.line_items ?? {}).every(
+          (items) => !items.length
+        )
+      },
+      set: (x) => x,
+    })
+
+    return response
+  }
+
+  useCart.extend = extendHook
+
+  return useCart
+}
+
+export default extendHook(fetcher)