Specifically ask for the Json Serializer object and not just relying on the interface that could change

Author: dmanners

Diff for: app/code/Magento/Captcha/Controller/Adminhtml/Refresh/Refresh.php

@@ -11,7 +11,7 @@
 class Refresh extends \Magento\Backend\App\Action
 {
     /**
-     * @var \Magento\Framework\Serialize\SerializerInterface
+     * @var \Magento\Framework\Serialize\Serializer\Json
      */
     protected $serializer;
 
@@ -24,17 +24,15 @@ class Refresh extends \Magento\Backend\App\Action
      * Refresh constructor.
      * @param \Magento\Backend\App\Action\Context $context
      * @param \Magento\Captcha\Helper\Data $captchaHelper
-     * @param \Magento\Framework\Serialize\SerializerInterface|null $serializer
-     * @throws \RuntimeException
+     * @param \Magento\Framework\Serialize\Serializer\Json $serializer
      */
     public function __construct(
         \Magento\Backend\App\Action\Context $context,
         \Magento\Captcha\Helper\Data $captchaHelper,
-        \Magento\Framework\Serialize\SerializerInterface $serializer = null
+        \Magento\Framework\Serialize\Serializer\Json $serializer
     ) {
         parent::__construct($context);
-        $this->serializer = $serializer ?: \Magento\Framework\App\ObjectManager::getInstance()
-            ->get(\Magento\Framework\Serialize\SerializerInterface::class);
+        $this->serializer = $serializer;
         $this->captchaHelper = $captchaHelper;
     }
 

Diff for: app/code/Magento/Captcha/Controller/Refresh/Index.php

@@ -18,24 +18,24 @@ class Index extends \Magento\Framework\App\Action\Action
     protected $captchaHelper;
 
     /**
-     * @var \Magento\Framework\Serialize\SerializerInterface
+     * @var \Magento\Framework\Serialize\Serializer\Json
      */
     protected $serializer;
 
     /**
      * @param Context $context
      * @param \Magento\Captcha\Helper\Data $captchaHelper
-     * @param \Magento\Framework\Serialize\SerializerInterface|null $serializer
+     * @param \Magento\Framework\Serialize\Serializer\Json|null $serializer
      * @throws \RuntimeException
      */
     public function __construct(
         Context $context,
         \Magento\Captcha\Helper\Data $captchaHelper,
-        \Magento\Framework\Serialize\SerializerInterface $serializer = null
+        \Magento\Framework\Serialize\Serializer\Json $serializer = null
     ) {
         $this->captchaHelper = $captchaHelper;
         $this->serializer = $serializer ?: \Magento\Framework\App\ObjectManager::getInstance()
-            ->get(\Magento\Framework\Serialize\SerializerInterface::class);
+            ->get(\Magento\Framework\Serialize\Serializer\Json::class);
         parent::__construct($context);
     }
 

Diff for: app/code/Magento/Captcha/Model/Customer/Plugin/AjaxLogin.php

@@ -27,7 +27,7 @@ class AjaxLogin
     protected $resultJsonFactory;
 
     /**
-     * @var \Magento\Framework\Serialize\SerializerInterface
+     * @var \Magento\Framework\Serialize\Serializer\Json
      */
     protected $serializer;
 
@@ -40,22 +40,22 @@ class AjaxLogin
      * @param CaptchaHelper $helper
      * @param SessionManagerInterface $sessionManager
      * @param JsonFactory $resultJsonFactory
-     * @param \Magento\Framework\Serialize\SerializerInterface|null $serializer
      * @param array $formIds
+     * @param \Magento\Framework\Serialize\Serializer\Json|null $serializer
      * @throws \RuntimeException
      */
     public function __construct(
         CaptchaHelper $helper,
         SessionManagerInterface $sessionManager,
         JsonFactory $resultJsonFactory,
         array $formIds,
-        \Magento\Framework\Serialize\SerializerInterface $serializer = null
+        \Magento\Framework\Serialize\Serializer\Json $serializer = null
     ) {
         $this->helper = $helper;
         $this->sessionManager = $sessionManager;
         $this->resultJsonFactory = $resultJsonFactory;
         $this->serializer = $serializer ?: \Magento\Framework\App\ObjectManager::getInstance()
-            ->get(\Magento\Framework\Serialize\SerializerInterface::class);
+            ->get(\Magento\Framework\Serialize\Serializer\Json::class);
         $this->formIds = $formIds;
     }
 

Diff for: app/code/Magento/Captcha/Test/Unit/Controller/Refresh/IndexTest.php

@@ -68,7 +68,7 @@ protected function setUp()
         $this->layoutMock = $this->getMock(\Magento\Framework\View\LayoutInterface::class);
         $this->flagMock = $this->getMock(\Magento\Framework\App\ActionFlag::class, [], [], '', false);
         $this->serializerMock = $this->getMock(
-            \Magento\Framework\Serialize\SerializerInterface::class,
+            \Magento\Framework\Serialize\Serializer\Json::class,
             [],
             [],
             '',

Diff for: app/code/Magento/Captcha/Test/Unit/Model/Customer/Plugin/AjaxLoginTest.php

@@ -85,7 +85,7 @@ protected function setUp()
             ->with('user_login')->will($this->returnValue($this->captchaMock));
         $this->formIds = ['user_login'];
         $this->serializerMock = $this->getMock(
-            \Magento\Framework\Serialize\SerializerInterface::class,
+            \Magento\Framework\Serialize\Serializer\Json::class,
             [],
             [],
             '',