Merge pull request #4 from pythonkr/fix/shop-cart-fail-on-not-initialized-cart

fix: 장바구니 컴포넌트가 렌더링되지 않을 수 있는 문제 수정

Author: MU-Software

package/pyconkr-shop/apis/index.ts

@@ -86,7 +86,7 @@ namespace ShopAPIRoute {
    * @returns 현재 장바구니 상태
    */
   export const retrieveCart = () =>
-    shopAPIClient.get<ShopAPISchema.Order>("v1/orders/cart/");
+    shopAPIClient.get<ShopAPISchema.Order | ShopAPISchema.EmptyObject>("v1/orders/cart/");
 
   /**
    * 장바구니에 상품을 추가합니다.

package/pyconkr-shop/schemas/index.ts

@@ -1,6 +1,8 @@
 import * as R from "remeda";
 
 namespace ShopAPISchema {
+  export type EmptyObject = Record<string, never>;
+
   export type DetailedErrorSchema = {
     code: string;
     detail: string;

src/debug/page/shop_component/cart.tsx

@@ -80,7 +80,7 @@ export const ShopCartList: React.FC<{ onPaymentCompleted?: () => void; }> = ({ o
       // eslint-disable-next-line react-hooks/rules-of-hooks
       const { data } = ShopAPIHook.useCart();
 
-      return data.products.length === 0
+      return !data.hasOwnProperty('products') || data.products.length === 0
         ? <Typography variant="body1" color="error">장바구니가 비어있어요!</Typography>
         : <>
           {data.products.map((prodRel) => <ShopCartItem key={prodRel.id} cartProdRel={prodRel} disabled={disabled} removeItemFromCartFunc={removeItemFromCart} />)}