✨ feat: 장바구니 상품 추가/수정 시 새로 등록된 상품 정보만 반환하도록 수정

Author: tl1l1l1s

src/main/java/com/jajaja/domain/cart/service/CartCommandServiceImpl.java

@@ -46,35 +46,32 @@ public class CartCommandServiceImpl implements CartCommandService {
 	@Override
 	public CartResponseDto addOrUpdateCartProduct(Long memberId, List<CartProductAddRequestDto> request) {
 		Cart cart = cartCommonService.findCart(memberId);
-		request.forEach(req -> {
+		List<CartProductResponseDto> items = request.stream().map(req -> {
 			log.info("[CartCommandService] 사용자 {}의 장바구니에 아이템 {} 추가/수정", memberId, req.productId());
 
 			CartOpterationContext context = prepareCartOperationContext(req.productId(), req.optionId());
 
 			Optional<CartProduct> existingItem = req.optionId() != null ? cartProductRepository.findByCartIdAndProductIdAndProductOptionId(cart.getId(), context.product().getId(), context.productOption.getId())
 					: cartProductRepository.findByCartIdAndProductIdAndProductOptionIsNull(cart.getId(), context.product().getId());
 
-			existingItem.ifPresentOrElse(
-					item -> {
+			CartProduct cartProduct = existingItem
+					.map(item -> {
 						log.info("[CartCommandService] 기존 아이템 {}의 옵션과 수량을 변경합니다.", item.getId());
 						item.update(context.productOption(), req.quantity());
-					},
-					() -> {
+						return item;
+					})
+					.orElseGet(() -> {
 						log.info("[CartCommandService] 장바구니에 새로 아이템 {}를 추가합니다.", req.productId());
 						CartProduct newCartProduct = CartProduct.create(cart, context.product(), context.productOption(), req.quantity());
 						cart.addCartProduct(newCartProduct);
-						cartProductRepository.save( newCartProduct);
-					}
-			);
-		});
-		
-		List<CartProductResponseDto> items = cart.getCartProducts().stream()
-						.map(cartProduct -> {
-							boolean isTeamAvailable = teamRepository.existsByProductIdAndStatus(cartProduct.getProduct().getId(), TeamStatus.MATCHING);
-							return CartProductResponseDto.of(cartProduct, productCommonService.calculateDiscountedPrice(cartProduct.getUnitPrice(), cartProduct.getProduct().getDiscountRate()), isTeamAvailable);
-						})
-				.toList();
-		
+						cartProductRepository.save(newCartProduct);
+						return newCartProduct;
+					});
+			
+			boolean isTeamAvailable = teamRepository.existsByProductIdAndStatus(
+					cartProduct.getProduct().getId(), TeamStatus.MATCHING);
+			return CartProductResponseDto.of(cartProduct, productCommonService.calculateDiscountedPrice(cartProduct.getUnitPrice(), cartProduct.getProduct().getDiscountRate()), isTeamAvailable);
+		}).toList();
 
 		PriceInfoDto priceInfo = cart.getCoupon() != null ?
 				couponCommonService.calculateDiscount(cart, cart.getCoupon()) :