MC-38995: Customer group price is not working in product query graphql

Author: Oleksandr Iegorov

app/code/Magento/CustomerGraphQl/Model/Context/AddCustomerGroupToContext.php

@@ -0,0 +1,68 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+declare(strict_types=1);
+
+namespace Magento\CustomerGraphQl\Model\Context;
+
+use Magento\Authorization\Model\UserContextInterface;
+use Magento\GraphQl\Model\Query\ContextParametersInterface;
+use Magento\GraphQl\Model\Query\ContextParametersProcessorInterface;
+use Magento\Customer\Model\Session as CustomerSession;
+use Magento\Customer\Model\Group;
+use Magento\Customer\Api\CustomerRepositoryInterface;
+use Magento\Framework\Exception\LocalizedException;
+
+/**
+ * @inheritdoc
+ */
+class AddCustomerGroupToContext implements ContextParametersProcessorInterface
+{
+    /**
+     * @var CustomerSession
+     */
+    private $customerSession;
+
+    /**
+     * @var CustomerRepositoryInterface
+     */
+    private $customerRepository;
+
+    /**
+     * @param CustomerSession $customerSession
+     * @param CustomerRepositoryInterface $customerRepository
+     */
+    public function __construct(
+        CustomerSession $customerSession,
+        CustomerRepositoryInterface $customerRepository
+    ) {
+        $this->customerSession = $customerSession;
+        $this->customerRepository = $customerRepository;
+    }
+
+    /**
+     * @inheritdoc
+     */
+    public function execute(ContextParametersInterface $contextParameters): ContextParametersInterface
+    {
+        $customerSession = $this->customerSession;
+        $customerGroupId = null;
+        if ($contextParameters->getUserType() === UserContextInterface::USER_TYPE_GUEST) {
+            $customerGroupId = Group::NOT_LOGGED_IN_ID;
+        } elseif ($contextParameters->getExtensionAttributes()->getIsCustomer() === true) {
+            try {
+                $customer = $this->customerRepository->getById($contextParameters->getUserId());
+                $customerGroupId = (int) $customer->getGroupId();
+            } catch (LocalizedException $e) {
+                $customerGroupId = null;
+            }
+        }
+        if ($customerGroupId !== null) {
+            $customerSession->setCustomerGroupId($customerGroupId);
+            $contextParameters->addExtensionAttribute('customer_group_id', $customerGroupId);
+        }
+        return $contextParameters;
+    }
+}

app/code/Magento/CustomerGraphQl/etc/graphql/di.xml

@@ -17,6 +17,7 @@
         <arguments>
             <argument name="contextParametersProcessors" xsi:type="array">
                 <item name="add_user_info_to_context" xsi:type="object">Magento\CustomerGraphQl\Model\Context\AddUserInfoToContext</item>
+                <item name="add_customer_group_to_context" xsi:type="object">Magento\CustomerGraphQl\Model\Context\AddCustomerGroupToContext</item>
             </argument>
         </arguments>
     </type>