fix: apply sreichel's suggestions

Author: hirale

app/code/core/Mage/Api2/Model/Auth/Adapter/Oauth2.php

@@ -1,4 +1,5 @@
 <?php
+
 /**
  * OpenMage
  *
@@ -17,18 +18,19 @@
  * @category   Mage
  * @package    Mage_Api2
  */
+
+declare(strict_types=1);
+
 class Mage_Api2_Model_Auth_Adapter_Oauth2 extends Mage_Api2_Model_Auth_Adapter_Abstract
 {
     /**
      * Process request and figure out an API user type and its identifier
      *
-     * Returns stdClass object with two properties: type and id
-     *
-     * @return stdClass
+     * Returns Varien_Object with two properties: type and id
      */
-    public function getUserParams(Mage_Api2_Model_Request $request)
+    public function getUserParams(Mage_Api2_Model_Request $request): Varien_Object
     {
-        $userParamsObj = (object) ['type' => null, 'id' => null];
+        $userParamsObj = new Varien_Object(['type' => null, 'id' => null]);
 
         try {
             $token = $this->_validateToken($request);

app/code/core/Mage/Oauth2/Block/Adminhtml/Client.php

@@ -14,6 +14,8 @@
  * @license    https://opensource.org/licenses/osl-3.0.php  Open Software License (OSL 3.0)
  */
 
+declare(strict_types=1);
+
 /**
  * OAuth2 Client Admin Grid Container
  */

app/code/core/Mage/Oauth2/Block/Adminhtml/Client/Edit.php

@@ -14,6 +14,8 @@
  * @license    https://opensource.org/licenses/osl-3.0.php  Open Software License (OSL 3.0)
  */
 
+ declare(strict_types=1);
+
 class Mage_Oauth2_Block_Adminhtml_Client_Edit extends Mage_Adminhtml_Block_Widget_Form_Container
 {
     protected $_model;
@@ -81,7 +83,7 @@ protected function _isAllowedAction($action)
     /**
      * Retrieves the model object from the registry if it is not already set.
      *
-     * @return mixed The model object from the registry.
+     * @return Mage_Oauth2_Model_Client The model object from the registry.
      */
     protected function getModel()
     {

app/code/core/Mage/Oauth2/Block/Adminhtml/Client/Edit/Form.php

@@ -14,6 +14,8 @@
  * @license    https://opensource.org/licenses/osl-3.0.php  Open Software License (OSL 3.0)
  */
 
+ declare(strict_types=1);
+
 class Mage_Oauth2_Block_Adminhtml_Client_Edit_Form extends Mage_Adminhtml_Block_Widget_Form
 {
     protected $_model;
@@ -88,7 +90,7 @@ protected function _prepareForm()
     /**
      * Retrieves the model object from the registry if it is not already set.
      *
-     * @return mixed The model object from the registry.
+     * @return Mage_Oauth2_Model_Client The model object from the registry.
      */
     protected function getModel()
     {

app/code/core/Mage/Oauth2/Block/Adminhtml/Client/Grid.php

@@ -14,6 +14,8 @@
  * @license    https://opensource.org/licenses/osl-3.0.php  Open Software License (OSL 3.0)
  */
 
+declare(strict_types=1);
+
 /**
  * OAuth2 Client Grid Block
  */

app/code/core/Mage/Oauth2/Block/Adminhtml/Text.php

@@ -14,6 +14,8 @@
  * @license    https://opensource.org/licenses/osl-3.0.php  Open Software License (OSL 3.0)
  */
 
+declare(strict_types=1);
+
 /**
  * Custom Text Form Element for OAuth2
  */

app/code/core/Mage/Oauth2/Block/Authorize.php

@@ -14,6 +14,8 @@
  * @license    https://opensource.org/licenses/osl-3.0.php  Open Software License (OSL 3.0)
  */
 
+declare(strict_types=1);
+
 /**
  * OAuth2 Authorization Block
  */

app/code/core/Mage/Oauth2/Block/Device/Verify.php

@@ -14,6 +14,8 @@
  * @license    https://opensource.org/licenses/osl-3.0.php  Open Software License (OSL 3.0)
  */
 
+declare(strict_types=1);
+
 /**
  * OAuth2 Device Verification Block
  */

app/code/core/Mage/Oauth2/Controller/BaseController.php

@@ -14,14 +14,16 @@
  * @license    https://opensource.org/licenses/osl-3.0.php  Open Software License (OSL 3.0)
  */
 
+declare(strict_types=1);
+
 class Mage_Oauth2_Controller_BaseController extends Mage_Core_Controller_Front_Action
 {
     /**
      * Send JSON response
      *
      * @param int $code HTTP status code
      * @param string $message Response message
-     * @param mixed|null $data Additional data (optional)
+     * @param array|null $data Additional data (optional)
      * @return void
      */
     protected function _sendResponse($code, $message, $data = null)

app/code/core/Mage/Oauth2/Helper/Data.php

@@ -14,6 +14,8 @@
  * @license    https://opensource.org/licenses/osl-3.0.php  Open Software License (OSL 3.0)
  */
 
+declare(strict_types=1);
+
 class Mage_Oauth2_Helper_Data extends Mage_Core_Helper_Abstract
 {
     /**