MAGETWO-88600: Error while saving Theme design configuration

Author: Dmytro Voskoboinikov

app/code/Magento/Theme/Controller/Adminhtml/Design/Config/Save.php

@@ -7,6 +7,7 @@
 
 use Magento\Backend\App\Action;
 use Magento\Framework\App\Request\DataPersistorInterface;
+use Magento\Framework\Exception\NotFoundException;
 use Magento\Theme\Model\DesignConfigRepository;
 use Magento\Backend\App\Action\Context;
 use Magento\Framework\Exception\LocalizedException;
@@ -62,9 +63,15 @@ protected function _isAllowed()
 
     /**
      * @return \Magento\Framework\Controller\Result\Redirect
+     *
+     * @throws NotFoundException
      */
     public function execute()
     {
+        if (!$this->getRequest()->isPost()) {
+            throw new NotFoundException(__('Page not found.'));
+        }
+
         $resultRedirect = $this->resultRedirectFactory->create();
         $scope = $this->getRequest()->getParam('scope');
         $scopeId = (int)$this->getRequest()->getParam('scope_id');
@@ -73,7 +80,7 @@ public function execute()
         try {
             $designConfigData = $this->configFactory->create($scope, $scopeId, $data);
             $this->designConfigRepository->save($designConfigData);
-            $this->messageManager->addSuccess(__('You saved the configuration.'));
+            $this->messageManager->addSuccessMessage(__('You saved the configuration.'));
 
             $this->dataPersistor->clear('theme_design_config');
 
@@ -86,10 +93,10 @@ public function execute()
         } catch (LocalizedException $e) {
             $messages = explode("\n", $e->getMessage());
             foreach ($messages as $message) {
-                $this->messageManager->addError(__('%1', $message));
+                $this->messageManager->addErrorMessage(__('%1', $message));
             }
         } catch (\Exception $e) {
-            $this->messageManager->addException(
+            $this->messageManager->addExceptionMessage(
                 $e,
                 __('Something went wrong while saving this configuration:') . ' ' . $e->getMessage()
             );

app/code/Magento/Theme/Test/Unit/Controller/Adminhtml/Design/Config/SaveTest.php

@@ -62,15 +62,13 @@ public function setUp()
             '',
             false
         );
-        $this->request = $this->getMockForAbstractClass(
-            \Magento\Framework\App\RequestInterface::class,
-            [],
-            '',
-            false,
-            false,
-            true,
-            ['getFiles', 'getParam', 'getParams']
-        );
+        $this->request = $this->getMockBuilder(\Magento\Framework\App\Request\Http::class)
+            ->disableOriginalConstructor()->getMock();
+
+        $this->request->expects($this->atLeastOnce())
+            ->method('isPost')
+            ->willReturn(true);
+
         $this->context = $objectManager->getObject(
             \Magento\Backend\App\Action\Context::class,
             [
@@ -138,7 +136,7 @@ public function testSave()
             ->method('save')
             ->with($this->designConfig);
         $this->messageManager->expects($this->once())
-            ->method('addSuccess')
+            ->method('addSuccessMessage')
             ->with(__('You saved the configuration.'));
         $this->dataPersistor->expects($this->once())
             ->method('clear')
@@ -194,7 +192,7 @@ public function testSaveWithLocalizedException()
             ->with($this->designConfig)
             ->willThrowException(new \Magento\Framework\Exception\LocalizedException(__('Exception message')));
         $this->messageManager->expects($this->once())
-            ->method('addError')
+            ->method('addErrorMessage')
             ->with(__('Exception message')->render());
 
         $this->dataPersistor->expects($this->once())
@@ -249,7 +247,7 @@ public function testSaveWithException()
             ->with($this->designConfig)
             ->willThrowException($exception);
         $this->messageManager->expects($this->once())
-            ->method('addException')
+            ->method('addExceptionMessage')
             ->with($exception, 'Something went wrong while saving this configuration: Exception message');
 
         $this->dataPersistor->expects($this->once())