MC-33899: [On-Premise] Product add to cart success message doesn’t show when cart contains out of stock product

Author: rostyslav-hymon

app/code/Magento/Checkout/Controller/Cart/Add.php

@@ -9,6 +9,8 @@
 use Magento\Framework\App\Action\HttpPostActionInterface as HttpPostActionInterface;
 use Magento\Catalog\Api\ProductRepositoryInterface;
 use Magento\Checkout\Model\Cart as CustomerCart;
+use Magento\Framework\App\ResponseInterface;
+use Magento\Framework\Controller\ResultInterface;
 use Magento\Framework\Exception\NoSuchEntityException;
 
 /**
@@ -77,7 +79,7 @@ protected function _initProduct()
     /**
      * Add product to shopping cart action
      *
-     * @return \Magento\Framework\Controller\Result\Redirect
+     * @return ResponseInterface|ResultInterface
      * @SuppressWarnings(PHPMD.CyclomaticComplexity)
      */
     public function execute()
@@ -90,7 +92,6 @@ public function execute()
         }
 
         $params = $this->getRequest()->getParams();
-
         try {
             if (isset($params['qty'])) {
                 $filter = new \Zend_Filter_LocalizedToNormalized(
@@ -104,9 +105,7 @@ public function execute()
             $product = $this->_initProduct();
             $related = $this->getRequest()->getParam('related_product');
 
-            /**
-             * Check product availability
-             */
+            /** Check product availability */
             if (!$product) {
                 return $this->goBack();
             }
@@ -115,7 +114,6 @@ public function execute()
             if (!empty($related)) {
                 $this->cart->addProductsByIds(explode(',', $related));
             }
-
             $this->cart->save();
 
             /**
@@ -127,21 +125,25 @@ public function execute()
             );
 
             if (!$this->_checkoutSession->getNoCartRedirect(true)) {
-                if (!$this->cart->getQuote()->getHasError()) {
-                    if ($this->shouldRedirectToCart()) {
-                        $message = __(
-                            'You added %1 to your shopping cart.',
-                            $product->getName()
-                        );
-                        $this->messageManager->addSuccessMessage($message);
-                    } else {
-                        $this->messageManager->addComplexSuccessMessage(
-                            'addCartSuccessMessage',
-                            [
-                                'product_name' => $product->getName(),
-                                'cart_url' => $this->getCartUrl(),
-                            ]
-                        );
+                if ($this->shouldRedirectToCart()) {
+                    $message = __(
+                        'You added %1 to your shopping cart.',
+                        $product->getName()
+                    );
+                    $this->messageManager->addSuccessMessage($message);
+                } else {
+                    $this->messageManager->addComplexSuccessMessage(
+                        'addCartSuccessMessage',
+                        [
+                            'product_name' => $product->getName(),
+                            'cart_url' => $this->getCartUrl(),
+                        ]
+                    );
+                }
+                if ($this->cart->getQuote()->getHasError()) {
+                    $errors = $this->cart->getQuote()->getErrors();
+                    foreach ($errors as $error) {
+                        $this->messageManager->addErrorMessage($error->getText());
                     }
                 }
                 return $this->goBack(null, $product);
@@ -161,7 +163,6 @@ public function execute()
             }
 
             $url = $this->_checkoutSession->getRedirectUrl(true);
-
             if (!$url) {
                 $url = $this->_redirect->getRedirectUrl($this->getCartUrl());
             }
@@ -175,14 +176,16 @@ public function execute()
             $this->_objectManager->get(\Psr\Log\LoggerInterface::class)->critical($e);
             return $this->goBack();
         }
+
+        return $this->getResponse();
     }
 
     /**
      * Resolve response
      *
      * @param string $backUrl
      * @param \Magento\Catalog\Model\Product $product
-     * @return $this|\Magento\Framework\Controller\Result\Redirect
+     * @return ResponseInterface|ResultInterface
      */
     protected function goBack($backUrl = null, $product = null)
     {
@@ -205,6 +208,8 @@ protected function goBack($backUrl = null, $product = null)
         $this->getResponse()->representJson(
             $this->_objectManager->get(\Magento\Framework\Json\Helper\Data::class)->jsonEncode($result)
         );
+
+        return $this->getResponse();
     }
 
     /**