/**
  * Validate post data
  *
  * @param array $pageData
  * @param \Magento\Cms\Model\Page $page
  * @param bool $error
  * @param array $messages
  * @return void
  */
 protected function validatePost(array $pageData, \Magento\Cms\Model\Page $page, &$error, array &$messages)
 {
     if (!($this->dataProcessor->validate($pageData) && $this->dataProcessor->validateRequireEntry($pageData))) {
         $error = true;
         foreach ($this->messageManager->getMessages(true)->getItems() as $error) {
             $messages[] = $this->getErrorWithPageId($page, $error->getText());
         }
     }
 }
 public function testValidateRequireEntry()
 {
     $postData = ['title' => ''];
     $this->messageManager->expects($this->once())->method('addError')->with(__('To apply changes you should fill in hidden required "%1" field', 'Page Title'));
     $this->assertFalse($this->postDataProcessor->validateRequireEntry($postData));
 }