add declare(strict_types=1);

Author: edenduong

app/code/Magento/Quote/Model/Quote/Item.php

@@ -3,6 +3,8 @@
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
+declare(strict_types=1);
+
 namespace Magento\Quote\Model\Quote;
 
 use Magento\Framework\Api\AttributeValueFactory;

app/code/Magento/Quote/Test/Unit/Model/Quote/Item/ProcessorTest.php

@@ -3,6 +3,8 @@
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
+declare(strict_types=1);
+
 namespace Magento\Quote\Test\Unit\Model\Quote\Item;
 
 use Magento\Catalog\Model\Product;

dev/tests/api-functional/testsuite/Magento/Catalog/Api/CartItemRepositoryTest.php

@@ -3,6 +3,8 @@
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
+declare(strict_types=1);
+
 namespace Magento\Catalog\Api;
 
 use Magento\TestFramework\TestCase\WebapiAbstract;