add strict types

Author: engcom-Charlie

app/code/Magento/Downloadable/Model/Link/UpdateHandler.php

@@ -3,6 +3,9 @@
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
+
+declare(strict_types=1);
+
 namespace Magento\Downloadable\Model\Link;
 
 use Magento\Catalog\Api\Data\ProductInterface;
@@ -33,16 +36,15 @@ public function __construct(LinkRepository $linkRepository)
     /**
      * Update links for downloadable product if exist
      *
-     * @param object $entity
+     * @param ProductInterface $entity
      * @param array $arguments
-     * @return ProductInterface|object
+     * @return ProductInterface
      * @SuppressWarnings(PHPMD.UnusedFormalParameter)
      */
-    public function execute($entity, $arguments = [])
+    public function execute($entity, $arguments = []): ProductInterface
     {
         $links = $entity->getExtensionAttributes()->getDownloadableProductLinks();
 
-        /** @var $entity ProductInterface */
         if ($links && $entity->getTypeId() === Type::TYPE_DOWNLOADABLE) {
             $this->updateLinks($entity, $links);
         }

app/code/Magento/Downloadable/Model/Sample/UpdateHandler.php

@@ -3,6 +3,9 @@
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
+
+declare(strict_types=1);
+
 namespace Magento\Downloadable\Model\Sample;
 
 use Magento\Catalog\Api\Data\ProductInterface;
@@ -33,16 +36,15 @@ public function __construct(SampleRepository $sampleRepository)
     /**
      * Update samples for downloadable product if exist
      *
-     * @param object $entity
+     * @param ProductInterface $entity
      * @param array $arguments
-     * @return ProductInterface|object
+     * @return ProductInterface
      * @SuppressWarnings(PHPMD.UnusedFormalParameter)
      */
-    public function execute($entity, $arguments = [])
+    public function execute($entity, $arguments = []): ProductInterface
     {
         $samples = $entity->getExtensionAttributes()->getDownloadableProductSamples();
 
-        /** @var $entity ProductInterface */
         if ($samples && $entity->getTypeId() === Type::TYPE_DOWNLOADABLE) {
             $this->updateSamples($entity, $samples);
         }

dev/tests/api-functional/testsuite/Magento/Downloadable/Api/ProductRepositoryTest.php

@@ -4,6 +4,8 @@
  * See COPYING.txt for license details.
  */
 
+declare(strict_types=1);
+
 namespace Magento\Downloadable\Api;
 
 use Magento\Catalog\Api\Data\ProductInterface;