[GraphQl][GiftMessage] Add functionality for getting message for order item

app/code/Magento/GiftMessageGraphQl/Model/Resolver/Order/GiftMessage.php

@@ -76,7 +76,8 @@ public function resolve(
             throw new GraphQlInputException(__('"id" value should be specified'));
         }
 
-        $orderId = $this->uidEncoder->decode((string) $this->uidEncoder->encode((string) $value['id']));
+        // phpcs:ignore Magento2.Functions.DiscouragedFunction
+        $orderId = (int)base64_decode($value['id']) ?: (int)$value['id'];
 
         try {
             $orderGiftMessage = $this->orderRepository->get($orderId);

app/code/Magento/GiftMessageGraphQl/Model/Resolver/Order/Item/GiftMessage.php

@@ -0,0 +1,97 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+declare(strict_types=1);
+
+namespace Magento\GiftMessageGraphQl\Model\Resolver\Order\Item;
+
+use Magento\Framework\Exception\LocalizedException;
+use Magento\Framework\GraphQl\Config\Element\Field;
+use Magento\Framework\GraphQl\Exception\GraphQlInputException;
+use Magento\Framework\GraphQl\Query\Resolver\ContextInterface;
+use Magento\Framework\GraphQl\Query\Resolver\Value;
+use Magento\Framework\GraphQl\Query\ResolverInterface;
+use Magento\Framework\GraphQl\Schema\Type\ResolveInfo;
+use Magento\GiftMessage\Api\OrderItemRepositoryInterface;
+use Magento\GiftMessage\Helper\Message as GiftMessageHelper;
+
+/**
+ * Class provides ability to get GiftMessage for order item
+ */
+class GiftMessage implements ResolverInterface
+{
+    /**
+     * @var OrderItemRepositoryInterface
+     */
+    private $orderItemRepository;
+
+    /**
+     * @var GiftMessageHelper
+     */
+    private $giftMessageHelper;
+
+    /**
+     * @param OrderItemRepositoryInterface $itemRepository
+     * @param GiftMessageHelper $giftMessageHelper
+     */
+    public function __construct(
+        OrderItemRepositoryInterface $itemRepository,
+        GiftMessageHelper $giftMessageHelper
+    ) {
+        $this->orderItemRepository = $itemRepository;
+        $this->giftMessageHelper = $giftMessageHelper;
+    }
+
+    /**
+     * Return information about Gift message for order item
+     *
+     * @param Field $field
+     * @param ContextInterface $context
+     * @param ResolveInfo $info
+     * @param array|null $value
+     * @param array|null $args
+     *
+     * @return array|Value|mixed
+     * @throws GraphQlInputException
+     * @SuppressWarnings(PHPMD.UnusedFormalParameter)
+     */
+    public function resolve(
+        Field $field,
+        $context,
+        ResolveInfo $info,
+        array $value = null,
+        array $args = null
+    ) {
+        if (!isset($value['model'])) {
+            throw new GraphQlInputException(__('"model" value must be specified'));
+        }
+
+        $orderItem = $value['model'];
+
+        if (!$this->giftMessageHelper->isMessagesAllowed('items', $orderItem)) {
+            return null;
+        }
+
+        if (!$this->giftMessageHelper->isMessagesAllowed('item', $orderItem)) {
+            return null;
+        }
+
+        try {
+            $giftItemMessage = $this->orderItemRepository->get($orderItem->getOrderId(), $orderItem->getItemId());
+        } catch (LocalizedException $e) {
+            throw new GraphQlInputException(__('Can\'t load message for order item'));
+        }
+
+        if ($giftItemMessage === null) {
+            return null;
+        }
+
+        return [
+            'to' => $giftItemMessage->getRecipient() ?? '',
+            'from' =>  $giftItemMessage->getSender() ?? '',
+            'message'=>  $giftItemMessage->getMessage() ?? ''
+        ];
+    }
+}

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

@@ -45,3 +45,7 @@ type SalesItemInterface {
 type CustomerOrder {
     gift_message: GiftMessage @resolver (class: "\\Magento\\GiftMessageGraphQl\\Model\\Resolver\\Order\\GiftMessage")  @doc(description: "The entered gift message for the order")
 }
+
+interface OrderItemInterface {
+    gift_message: GiftMessage @resolver(class: "\\Magento\\GiftMessageGraphQl\\Model\\Resolver\\Order\\Item\\GiftMessage") @doc(description: "The selected gift message for the order item")
+}

dev/tests/api-functional/testsuite/Magento/GraphQl/GiftMessage/Order/GiftMessageTest.php

@@ -48,6 +48,44 @@ public function testGiftMessageForOrder()
         }
     }
 
+    /**
+     * @magentoConfigFixture default_store sales/gift_options/allow_order 1
+     * @magentoConfigFixture default_store sales/gift_options/allow_items 1
+     * @magentoApiDataFixture Magento/Customer/_files/customer.php
+     * @magentoApiDataFixture Magento/GiftMessage/_files/customer/order_with_message.php
+     * @throws AuthenticationException
+     * @throws Exception
+     */
+    public function testGiftMessageForCustomerOrder()
+    {
+        $query = <<<QUERY
+query {
+  customer {
+   orders(filter:{number:{eq:"999999991"}}){
+    total_count
+    items
+    {
+      gift_message {
+        from
+        to
+        message
+      }
+     }
+   }
+ }
+}
+QUERY;
+        $currentEmail = 'customer@example.com';
+        $currentPassword = 'password';
+        $response = $this->graphQlQuery($query, [], '', $this->getCustomerAuthHeaders($currentEmail, $currentPassword));
+        foreach ($response['customer']['orders']['items'] as $order) {
+            self::assertArrayHasKey('gift_message', $order);
+            self::assertSame('Jane Roe', $order['gift_message']['to']);
+            self::assertSame('John Doe', $order['gift_message']['from']);
+            self::assertSame('Gift Message Text', $order['gift_message']['message']);
+        }
+    }
+
     /**
      * @magentoConfigFixture default_store sales/gift_options/allow_order 0
      * @magentoConfigFixture default_store sales/gift_options/allow_items 0

dev/tests/api-functional/testsuite/Magento/GraphQl/GiftMessage/Order/Item/GiftMessageTest.php

@@ -0,0 +1,85 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+declare(strict_types=1);
+
+namespace Magento\GraphQl\GiftMessage\Order\Item;
+
+use Exception;
+use Magento\Framework\Exception\AuthenticationException;
+use Magento\Integration\Api\CustomerTokenServiceInterface;
+use Magento\TestFramework\Helper\Bootstrap;
+use Magento\TestFramework\TestCase\GraphQlAbstract;
+
+class GiftMessageTest extends GraphQlAbstract
+{
+    /**
+     * @var CustomerTokenServiceInterface
+     */
+    private $customerTokenService;
+
+    protected function setUp(): void
+    {
+        parent::setUp();
+        $this->customerTokenService = Bootstrap::getObjectManager()->get(CustomerTokenServiceInterface::class);
+    }
+
+    /**
+     * @magentoConfigFixture default_store sales/gift_options/allow_order 1
+     * @magentoConfigFixture default_store sales/gift_options/allow_items 1
+     * @magentoApiDataFixture Magento/Customer/_files/customer.php
+     * @magentoApiDataFixture Magento/GiftMessage/_files/customer/order_with_message.php
+     * @throws AuthenticationException
+     * @throws Exception
+     */
+    public function testGiftMessageForOrderItem()
+    {
+        $query = <<<QUERY
+query {
+  customer {
+   orders(filter:{number:{eq:"999999991"}}){
+    total_count
+    items {
+       id
+       items{
+         gift_message {
+            from
+            to
+            message
+         }
+       }
+      gift_message {
+        from
+        to
+        message
+      }
+     }
+   }
+ }
+}
+QUERY;
+        $currentEmail = 'customer@example.com';
+        $currentPassword = 'password';
+        $response = $this->graphQlQuery($query, [], '', $this->getCustomerAuthHeaders($currentEmail, $currentPassword));
+        foreach ($response['customer']['orders']['items'][0]['items'] as $item) {
+            self::assertArrayHasKey('gift_message', $item);
+            self::assertSame('Luci', $item['gift_message']['to']);
+            self::assertSame('Jack', $item['gift_message']['from']);
+            self::assertSame('Good Job!', $item['gift_message']['message']);
+        }
+    }
+
+    /**
+     * @param string $email
+     * @param string $password
+     * @return array
+     * @throws AuthenticationException
+     */
+    private function getCustomerAuthHeaders(string $email, string $password): array
+    {
+        $customerToken = $this->customerTokenService->createCustomerAccessToken($email, $password);
+        return ['Authorization' => 'Bearer ' . $customerToken];
+    }
+}

dev/tests/integration/testsuite/Magento/GiftMessage/_files/customer/order_with_message.php

@@ -79,14 +79,25 @@
     $messageModel->setMessage('Gift Message Text');
     $message->save($messageModel);
 
+    /** @var MessageResource $productMessage */
+    $productMessage = $objectManager->create(MessageResource::class);
+    /** @var Message $productMessageModel */
+    $productMessageModel = $objectManager->create(Message::class);
+
+    $productMessageModel->setSender('Jack');
+    $productMessageModel->setRecipient('Luci');
+    $productMessageModel->setMessage('Good Job!');
+    $productMessage->save($productMessageModel);
+
     /** @var Order\Item $orderItem */
     $orderItem = $objectManager->create(Order\Item::class);
     $orderItem->setProductId($product->getId())
         ->setQtyOrdered(2)
         ->setBasePrice($product->getPrice())
         ->setPrice($product->getPrice())
         ->setRowTotal($product->getPrice())
-        ->setProductType('simple');
+        ->setProductType('simple')
+        ->setGiftMessageId($productMessageModel->getId());
 
     $order
         ->setData($orderData)