Mutation for updating cart item quantities

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

@@ -0,0 +1,58 @@
+<?php
+declare(strict_types=1);
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+namespace Magento\QuoteGraphQl\Model\Cart;
+
+use Magento\Framework\Exception\NoSuchEntityException;
+use Magento\Quote\Model\Quote;
+use Magento\Quote\Api\CartRepositoryInterface;
+use Magento\Quote\Api\GuestCartRepositoryInterface;
+
+class UpdateCartItems
+{
+    /**
+     * @var CartRepositoryInterface
+     */
+    private $quoteRepository;
+
+    /**
+     * @var GuestCartRepositoryInterface
+     */
+    private $guestCartRepository;
+
+    public function __construct(
+        CartRepositoryInterface $quoteRepository,
+        GuestCartRepositoryInterface $guestCartRepository
+    ) {
+        $this->quoteRepository = $quoteRepository;
+        $this->guestCartRepository = $guestCartRepository;
+    }
+
+    public function update(string $maskedCartId, array $items): Quote
+    {
+        $quote = $this->guestCartRepository->get($maskedCartId);
+
+        foreach ($items as $item) {
+            $quoteItem = $quote->getItemById($item['item_id']);
+            if ($quoteItem === false) {
+                throw new NoSuchEntityException(__('Could not find cart item with id: %1', $item['item_id']));
+            }
+
+            $qty = $item['qty'];
+
+            if ($qty <= 0.0) {
+                $quote->removeItem($quoteItem->getItemId());
+                continue;
+            }
+
+            $quoteItem->setQty($qty);
+        }
+
+        $this->quoteRepository->save($quote);
+
+        return $quote;
+    }
+}

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

@@ -0,0 +1,74 @@
+<?php
+declare(strict_types=1);
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+namespace Magento\QuoteGraphQl\Model\Resolver;
+
+use Magento\Framework\Exception\NoSuchEntityException;
+use Magento\Framework\GraphQl\Config\Element\Field;
+use Magento\Framework\GraphQl\Exception\GraphQlInputException;
+use Magento\Framework\GraphQl\Exception\GraphQlNoSuchEntityException;
+use Magento\Framework\GraphQl\Query\ResolverInterface;
+use Magento\Framework\GraphQl\Schema\Type\ResolveInfo;
+use Magento\Quote\Api\GuestCartRepositoryInterface;
+use Magento\QuoteGraphQl\Model\Cart\ExtractDataFromCart;
+use Magento\Framework\Stdlib\ArrayManager;
+use Magento\QuoteGraphQl\Model\Cart\UpdateCartItems as UpdateCartItemsService;
+
+class UpdateCartItems implements ResolverInterface
+{
+    /**
+     * @var ExtractDataFromCart
+     */
+    private $extractDataFromCart;
+
+    /**
+     * @var ArrayManager
+     */
+    private $arrayManager;
+
+    /**
+     * @var UpdateCartItemsService
+     */
+    private $updateCartItems;
+
+    /**
+     * @param ExtractDataFromCart $extractDataFromCart
+     * @param ArrayManager $arrayManager
+     * @param UpdateCartItemsService $updateCartItems
+     */
+    public function __construct(
+        ExtractDataFromCart $extractDataFromCart,
+        ArrayManager $arrayManager,
+        UpdateCartItemsService $updateCartItems
+    ) {
+        $this->extractDataFromCart = $extractDataFromCart;
+        $this->arrayManager = $arrayManager;
+        $this->updateCartItems = $updateCartItems;
+    }
+
+    public function resolve(Field $field, $context, ResolveInfo $info, array $value = null, array $args = null)
+    {
+        $cartItems = $this->arrayManager->get('input/cart_items', $args);
+        $maskedCartId = $this->arrayManager->get('input/cart_id', $args);
+
+        if (!$maskedCartId) {
+            throw new GraphQlInputException(__('Required parameter "cart_id" is missing'));
+        }
+        if (!$cartItems) {
+            throw new GraphQlInputException(__('Required parameter "cart_items  " is missing'));
+        }
+
+        try {
+            $cart = $this->updateCartItems->update($maskedCartId, $cartItems);
+        } catch (NoSuchEntityException $e) {
+            throw new GraphQlNoSuchEntityException(__($e->getMessage()));
+        }
+
+        $cartData = $this->extractDataFromCart->execute($cart);
+
+        return ['cart' => array_merge(['cart_id' => $maskedCartId], $cartData)];
+    }
+}

app/code/Magento/QuoteGraphQl/etc/schema.graphqls

@@ -14,6 +14,7 @@ type Mutation {
     setShippingAddressesOnCart(input: SetShippingAddressesOnCartInput): SetShippingAddressesOnCartOutput @resolver(class: "\\Magento\\QuoteGraphQl\\Model\\Resolver\\SetShippingAddressesOnCart")
     setBillingAddressOnCart(input: SetBillingAddressOnCartInput): SetBillingAddressOnCartOutput @resolver(class: "\\Magento\\QuoteGraphQl\\Model\\Resolver\\SetBillingAddressOnCart")
     setShippingMethodsOnCart(input: SetShippingMethodsOnCartInput): SetShippingMethodsOnCartOutput @resolver(class: "\\Magento\\QuoteGraphQl\\Model\\Resolver\\SetShippingMethodsOnCart")
+    updateCartItems(input: UpdateCartItemsInput): UpdateCartItemsOutput @resolver(class: "Magento\\QuoteGraphQl\\Model\\Resolver\\UpdateCartItems")
 }
 
 input AddSimpleProductsToCartInput {
@@ -206,6 +207,20 @@ type AddVirtualProductsToCartOutput {
     cart: Cart!
 }
 
+input UpdateCartItemsInput {
+    cart_id: String!
+    cart_items: [UpdateCartItemInput!]!
+}
+
+input UpdateCartItemInput {
+    item_id: String!
+    qty: Float!
+}
+
+type UpdateCartItemsOutput {
+    cart: Cart!
+}
+
 type SimpleCartItem implements CartItemInterface @doc(description: "Simple Cart Item") {
     customizable_options: [SelectedCustomizableOption] @resolver(class: "Magento\\QuoteGraphQl\\Model\\Resolver\\CustomizableOptions")
 }

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

@@ -0,0 +1,143 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+declare(strict_types=1);
+
+namespace Magento\GraphQl\Quote;
+
+use Magento\Catalog\Api\ProductRepositoryInterface;
+use Magento\Quote\Model\Quote;
+use Magento\Quote\Model\QuoteIdToMaskedQuoteIdInterface;
+use Magento\Quote\Model\ResourceModel\Quote as QuoteResource;
+use Magento\TestFramework\Helper\Bootstrap;
+use Magento\TestFramework\TestCase\GraphQlAbstract;
+
+/**
+ * Test for updating/removing shopping cart items
+ */
+class UpdateCartItemsTest extends GraphQlAbstract
+{
+    /**
+     * @var QuoteResource
+     */
+    private $quoteResource;
+
+    /**
+     * @var Quote
+     */
+    private $quote;
+
+    /**
+     * @var QuoteIdToMaskedQuoteIdInterface
+     */
+    private $quoteIdToMaskedId;
+
+    /**
+     * @var ProductRepositoryInterface
+     */
+    private $productRepository;
+
+    protected function setUp()
+    {
+        $objectManager = Bootstrap::getObjectManager();
+        $this->quoteResource = $objectManager->create(QuoteResource::class);
+        $this->quote = $objectManager->create(Quote::class);
+        $this->quoteIdToMaskedId = $objectManager->get(QuoteIdToMaskedQuoteIdInterface::class);
+        $this->productRepository = $objectManager->get(ProductRepositoryInterface::class);
+    }
+
+    /**
+     * @magentoApiDataFixture Magento/Checkout/_files/quote_with_simple_product_saved.php
+     */
+    public function testUpdateCartItemQty()
+    {
+        $this->quoteResource->load(
+            $this->quote,
+            'test_order_with_simple_product_without_address',
+            'reserved_order_id'
+        );
+        $maskedQuoteId = $this->quoteIdToMaskedId->execute((int)$this->quote->getId());
+        $quoteItem = $this->quote->getItemByProduct($this->productRepository->get('simple'));
+        $qty = $quoteItem->getQty() + 2;
+
+        $query = $this->prepareUpdateItemsQuery($maskedQuoteId, (string) $quoteItem->getItemId(), $qty);
+        $response = $this->graphQlQuery($query);
+
+        $this->assertArrayHasKey('updateCartItems', $response);
+        $this->assertArrayHasKey('cart', $response['updateCartItems']);
+
+        $responseCart = $response['updateCartItems']['cart'];
+        $item = current($responseCart['items']);
+
+        $this->assertEquals($quoteItem->getItemId(), $item['id']);
+        $this->assertEquals($qty, $item['qty']);
+    }
+
+    /**
+     * @magentoApiDataFixture Magento/Checkout/_files/quote_with_simple_product_saved.php
+     */
+    public function testRemoveCartItemByZeroQuantityUpdate()
+    {
+        $this->quoteResource->load(
+            $this->quote,
+            'test_order_with_simple_product_without_address',
+            'reserved_order_id'
+        );
+        $maskedQuoteId = $this->quoteIdToMaskedId->execute((int)$this->quote->getId());
+        $quoteItem = $this->quote->getItemByProduct($this->productRepository->get('simple'));
+
+        $query = $this->prepareUpdateItemsQuery($maskedQuoteId, (string) $quoteItem->getItemId(), 0);
+        $response = $this->graphQlQuery($query);
+
+        $this->assertArrayHasKey('updateCartItems', $response);
+        $this->assertArrayHasKey('cart', $response['updateCartItems']);
+
+        $responseCart = $response['updateCartItems']['cart'];
+        $this->assertCount(0, $responseCart['items']);
+    }
+
+    /**
+     * @magentoApiDataFixture Magento/Checkout/_files/quote_with_simple_product_saved.php
+     * @expectedException \Exception
+     * @expectedExceptionMessage Could not find cart item with id
+     */
+    public function testUpdateCartItemNoSuchItemEntity()
+    {
+        $this->quoteResource->load(
+            $this->quote,
+            'test_order_with_simple_product_without_address',
+            'reserved_order_id'
+        );
+        $maskedQuoteId = $this->quoteIdToMaskedId->execute((int)$this->quote->getId());
+
+        $query = $this->prepareUpdateItemsQuery($maskedQuoteId, '999', 4);
+        $this->graphQlQuery($query);
+    }
+
+    private function prepareUpdateItemsQuery(string $maskedQuoteId, string $itemId, float $qty): string
+    {
+        return <<<QUERY
+mutation {
+  updateCartItems(input:{
+    cart_id:"$maskedQuoteId"
+    cart_items:[
+      {
+        item_id:"$itemId"
+        qty: $qty
+      }
+    ]
+  }) {
+    cart {
+      cart_id
+      items {
+        id
+        qty
+      }
+    }
+  }
+}
+QUERY;
+    }
+}