GraphQl-439: Improve coverage for mutation addSimpleProductToCart or Cart contains a product after product got status Out of Stock

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

@@ -8,7 +8,6 @@
 namespace Magento\QuoteGraphQl\Model\Cart;
 
 use Magento\Framework\GraphQl\Exception\GraphQlInputException;
-use Magento\Framework\Message\AbstractMessage;
 use Magento\Quote\Api\CartRepositoryInterface;
 use Magento\Quote\Model\Quote;
 
@@ -53,31 +52,6 @@ public function execute(Quote $cart, array $cartItems): void
         foreach ($cartItems as $cartItemData) {
             $this->addProductToCart->execute($cart, $cartItemData);
         }
-
-        if ($cart->getData('has_error')) {
-            throw new GraphQlInputException(
-                __('Shopping cart error: %message', ['message' => $this->getCartErrors($cart)])
-            );
-        }
-
         $this->cartRepository->save($cart);
     }
-
-    /**
-     * Collecting cart errors
-     *
-     * @param Quote $cart
-     * @return string
-     */
-    private function getCartErrors(Quote $cart): string
-    {
-        $errorMessages = [];
-
-        /** @var AbstractMessage $error */
-        foreach ($cart->getErrors() as $error) {
-            $errorMessages[] = $error->getText();
-        }
-
-        return implode(PHP_EOL, $errorMessages);
-    }
 }

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

@@ -0,0 +1,57 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+declare(strict_types=1);
+
+namespace Magento\QuoteGraphQl\Model\Resolver;
+
+use Magento\Framework\Exception\LocalizedException;
+use Magento\Framework\GraphQl\Config\Element\Field;
+use Magento\Framework\GraphQl\Query\ResolverInterface;
+use Magento\Framework\GraphQl\Schema\Type\ResolveInfo;
+use Magento\Quote\Model\Quote;
+use Magento\Framework\GraphQl\Exception\GraphQlNoSuchEntityException;
+
+/**
+ * @inheritdoc
+ */
+class CartMessages implements ResolverInterface
+{
+    /**
+     * @inheritdoc
+     */
+    public function resolve(Field $field, $context, ResolveInfo $info, array $value = null, array $args = null)
+    {
+        if (!isset($value['model'])) {
+            throw new LocalizedException(__('"model" value should be specified'));
+        }
+        $cart = $value['model'];
+        if (empty($cart->getData('has_error'))) {
+            return [];
+        }
+        return $this->getCartErrors($cart);
+    }
+
+    /**
+     * Collecting cart errors
+     *
+     * @param Quote $cart
+     * @return array
+     */
+    private function getCartErrors(Quote $cart): array
+    {
+        $errorMessages = [];
+
+        /** @var AbstractMessage $error */
+        foreach ($cart->getMessages() as $idettifier => $error) {
+            $errorMessages[] = [
+                'identifier' => $idettifier,
+                'text' => $error->getText()
+            ];
+        }
+
+        return $errorMessages;
+    }
+}

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

@@ -206,6 +206,7 @@ type Cart {
     prices: CartPrices @resolver(class: "\\Magento\\QuoteGraphQl\\Model\\Resolver\\CartPrices")
     total_quantity: Float! @resolver(class: "\\Magento\\QuoteGraphQl\\Model\\Resolver\\CartTotalQuantity")
     is_virtual: Boolean! @resolver(class: "\\Magento\\QuoteGraphQl\\Model\\Resolver\\CartIsVirtual")
+    messages: [Message] @resolver(class: "\\Magento\\QuoteGraphQl\\Model\\Resolver\\CartMessages") @doc(description:"Return all shopping cart messages for a guest or logged in user")
 }
 
 interface CartAddressInterface @typeResolver(class: "\\Magento\\QuoteGraphQl\\Model\\Resolver\\CartAddressTypeResolver") {
@@ -366,3 +367,8 @@ type Order {
     order_number: String!
     order_id: String @deprecated(reason: "The order_id field is deprecated, use order_number instead.")
 }
+
+type Message {
+    identifier: String
+    text: String
+}

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

@@ -0,0 +1,136 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+declare(strict_types=1);
+
+namespace Magento\GraphQl\Quote;
+
+use Magento\TestFramework\Helper\Bootstrap;
+use Magento\TestFramework\TestCase\GraphQlAbstract;
+use Magento\Quote\Model\QuoteFactory;
+use Magento\Quote\Model\QuoteIdToMaskedQuoteIdInterface;
+use Magento\Quote\Model\ResourceModel\Quote as QuoteResource;
+use Magento\GraphQl\Quote\GetMaskedQuoteIdByReservedOrderId;
+use Magento\Integration\Api\CustomerTokenServiceInterface;
+
+/**
+ * Class GetCartMessagesTest
+ *
+ * @package Magento\GraphQl\Quote
+ */
+class CartMessagesTest extends GraphQlAbstract
+{
+    /**
+     * @var QuoteResource
+     */
+    private $quoteResource;
+
+    /**
+     * @var QuoteFactory
+     */
+    private $quoteFactory;
+
+    /**
+     * @var QuoteIdToMaskedQuoteIdInterface
+     */
+    private $quoteIdToMaskedId;
+
+    /**
+     * @var GetMaskedQuoteIdByReservedOrderId
+     */
+    private $getMaskedQuoteIdByReservedOrderId;
+
+    /**
+     * @var CustomerTokenServiceInterface
+     */
+    private $customerTokenService;
+
+    /**
+     * @inheritdoc
+     */
+    protected function setUp()
+    {
+        $objectManager = Bootstrap::getObjectManager();
+        $this->quoteResource = $objectManager->get(QuoteResource::class);
+        $this->quoteFactory = $objectManager->get(QuoteFactory::class);
+        $this->quoteIdToMaskedId = $objectManager->get(QuoteIdToMaskedQuoteIdInterface::class);
+        $this->getMaskedQuoteIdByReservedOrderId = $objectManager->get(GetMaskedQuoteIdByReservedOrderId::class);
+        $this->customerTokenService = $objectManager->get(CustomerTokenServiceInterface::class);
+    }
+
+    /**
+     * @magentoApiDataFixture Magento/Checkout/_files/active_quote.php
+     */
+    public function testCartWithoutErrors()
+    {
+        $maskedQuoteId = $this->getMaskedQuoteId();
+
+        $query = $this->getCartMessagesQuery($maskedQuoteId);
+        $response = $this->graphQlMutation($query);
+        self::assertEquals([], $response['cart']['messages']);
+    }
+
+    /**
+     * @magentoApiDataFixture Magento/Customer/_files/customer.php
+     * @magentoApiDataFixture Magento/GraphQl/Catalog/_files/simple_product.php
+     * @magentoApiDataFixture Magento/GraphQl/Quote/_files/customer/create_empty_cart.php
+     * @magentoApiDataFixture Magento/GraphQl/Quote/_files/add_simple_product.php
+     * @magentoApiDataFixture Magento/GraphQl/Catalog/_files/set_simple_product_out_of_stock.php
+     */
+    public function testCartWithOutOfStockProduct()
+    {
+        $reservedOrderId = 'test_quote';
+        $maskedQuoteId = $this->getMaskedQuoteIdByReservedOrderId->execute($reservedOrderId);
+
+        $query = $this->getCartMessagesQuery($maskedQuoteId);
+
+        $response = $this->graphQlMutation($query, [], '', $this->getHeaderMap());
+        self::assertEquals('Some of the products are out of stock.', $response['cart']['messages'][0]['text']);
+    }
+
+    /**
+     * @return string
+     * @throws \Magento\Framework\Exception\NoSuchEntityException
+     */
+    public function getMaskedQuoteId() : string
+    {
+        $quote = $this->quoteFactory->create();
+        $this->quoteResource->load($quote, 'test_order_1', 'reserved_order_id');
+
+        return $this->quoteIdToMaskedId->execute((int)$quote->getId());
+    }
+
+    /**
+     * @param string $maskedQuoteId
+     * @return string
+     */
+    public function getCartMessagesQuery(string $maskedQuoteId): string
+    {
+        return <<<QUERY
+{
+    cart(cart_id:"{$maskedQuoteId}"){
+    messages{
+        text
+    }
+  }
+} 
+QUERY;
+    }
+
+    /**
+     * Retrieve customer authorization headers
+     *
+     * @param string $username
+     * @param string $password
+     * @return array
+     * @throws AuthenticationException
+     */
+    private function getHeaderMap(string $username = '[email protected]', string $password = 'password'): array
+    {
+        $customerToken = $this->customerTokenService->createCustomerAccessToken($username, $password);
+        $headerMap = ['Authorization' => 'Bearer ' . $customerToken];
+        return $headerMap;
+    }
+}