MC-19194: UpdateCartItems mutation does not update cart item quantity

- fix performance issue

Author: danielrenaud

app/code/Magento/QuoteGraphQl/Model/Cart/UpdateCartItem.php

@@ -93,8 +93,6 @@ public function execute(Quote $cart, int $cartItemId, float $quantity, array $cu
                 )
             );
         }
-
-        $this->quoteRepository->save($cart);
     }
 
     /**
@@ -105,7 +103,7 @@ public function execute(Quote $cart, int $cartItemId, float $quantity, array $cu
      * @param float $quantity
      * @throws GraphQlNoSuchEntityException
      * @throws NoSuchEntityException
-     * @throws GraphQlNoSuchEntityException
+     * @throws GraphQlInputException
      */
     private function updateItemQuantity(int $itemId, Quote $cart, float $quantity)
     {
@@ -117,7 +115,6 @@ private function updateItemQuantity(int $itemId, Quote $cart, float $quantity)
         }
         $cartItem->setQty($quantity);
         $this->validateCartItem($cartItem);
-        $this->cartItemRepository->save($cartItem);
     }
 
     /**

app/code/Magento/QuoteGraphQl/Model/Resolver/UpdateCartItems.php

@@ -15,6 +15,7 @@
 use Magento\Framework\GraphQl\Query\ResolverInterface;
 use Magento\Framework\GraphQl\Schema\Type\ResolveInfo;
 use Magento\Quote\Api\CartItemRepositoryInterface;
+use Magento\Quote\Api\CartRepositoryInterface;
 use Magento\Quote\Model\Quote;
 use Magento\QuoteGraphQl\Model\Cart\GetCartForUser;
 use Magento\QuoteGraphQl\Model\Cart\UpdateCartItem;
@@ -39,19 +40,27 @@ class UpdateCartItems implements ResolverInterface
      */
     private $cartItemRepository;
 
+    /**
+     * @var CartRepositoryInterface
+     */
+    private $cartRepository;
+
     /**
      * @param GetCartForUser $getCartForUser
      * @param CartItemRepositoryInterface $cartItemRepository
      * @param UpdateCartItem $updateCartItem
+     * @param CartRepositoryInterface $cartRepository
      */
     public function __construct(
         GetCartForUser $getCartForUser,
         CartItemRepositoryInterface $cartItemRepository,
-        UpdateCartItem $updateCartItem
+        UpdateCartItem $updateCartItem,
+        CartRepositoryInterface $cartRepository
     ) {
         $this->getCartForUser = $getCartForUser;
         $this->cartItemRepository = $cartItemRepository;
         $this->updateCartItem = $updateCartItem;
+        $this->cartRepository = $cartRepository;
     }
 
     /**
@@ -76,6 +85,7 @@ public function resolve(Field $field, $context, ResolveInfo $info, array $value
 
         try {
             $this->processCartItems($cart, $cartItems);
+            $this->cartRepository->save($cart);
         } catch (NoSuchEntityException $e) {
             throw new GraphQlNoSuchEntityException(__($e->getMessage()), $e);
         } catch (LocalizedException $e) {

dev/tests/api-functional/testsuite/Magento/GraphQl/Quote/Guest/UpdateCartItemsTest.php

@@ -71,6 +71,7 @@ public function testUpdateCartItemQuantity()
         $this->assertEquals($itemId, $item['id']);
         $this->assertEquals($quantity, $item['quantity']);
 
+        //Check that update is correctly reflected in cart
         $cartQuery = $this->getCartQuery($maskedQuoteId);
         $response = $this->graphQlQuery($cartQuery);
 
@@ -101,6 +102,15 @@ public function testRemoveCartItemIfQuantityIsZero()
 
         $responseCart = $response['updateCartItems']['cart'];
         $this->assertCount(0, $responseCart['items']);
+
+        //Check that update is correctly reflected in cart
+        $cartQuery = $this->getCartQuery($maskedQuoteId);
+        $response = $this->graphQlQuery($cartQuery);
+
+        $this->assertArrayHasKey('cart', $response);
+
+        $responseCart = $response['cart'];
+        $this->assertCount(0, $responseCart['items']);
     }
 
     /**