MAGETWO-53501: Coupon can not be cancelled when total is less then minimum order amount

Author: Stanislav Idolov

app/code/Magento/Checkout/Block/Cart/ValidationMessages.php

@@ -22,7 +22,7 @@ class ValidationMessages extends \Magento\Framework\View\Element\Messages
     /**
      * @var \Magento\Quote\Model\Quote\Validator\MinimumOrderAmount\ValidationMessage
      */
-    private $validationMessages;
+    private $minimumAmountErrorMessage;
 
     /**
      * @param \Magento\Framework\View\Element\Template\Context $context
@@ -78,22 +78,23 @@ protected function _prepareLayout()
     protected function validateMinimumAmount()
     {
         if (!$this->cartHelper->getQuote()->validateMinimumAmount()) {
-            $this->messageManager->addNotice($this->getMinimumAmountErrorMessageDependency()->getMessage());
+            $this->messageManager->addNotice($this->getMinimumAmountErrorMessage()->getMessage());
         }
     }
 
     /**
      * @return \Magento\Quote\Model\Quote\Validator\MinimumOrderAmount\ValidationMessage
+     * @deprecated
      */
-    private function getMinimumAmountErrorMessageDependency()
+    private function getMinimumAmountErrorMessage()
     {
-        if ($this->validationMessages === null) {
+        if ($this->minimumAmountErrorMessage === null) {
             $objectManager = ObjectManager::getInstance();
-            $this->validationMessages = $objectManager->get(
+            $this->minimumAmountErrorMessage = $objectManager->get(
                 \Magento\Quote\Model\Quote\Validator\MinimumOrderAmount\ValidationMessage::class
             );
         }
-        return $this->validationMessages;
+        return $this->minimumAmountErrorMessage;
     }
 
     /**

app/code/Magento/Quote/Model/Quote/Validator/MinimumOrderAmount/ValidationMessage.php

@@ -38,7 +38,7 @@ public function __construct(
     }
 
     /**
-     * @return \Magento\Framework\Phrase
+     * @return \Magento\Framework\Phrase|mixed
      * @throws \Zend_Currency_Exception
      */
     public function getMessage()

app/code/Magento/Quote/Model/ShippingAddressManagement.php

@@ -55,7 +55,7 @@ class ShippingAddressManagement implements \Magento\Quote\Model\ShippingAddressM
     /**
      * @var \Magento\Quote\Model\Quote\Validator\MinimumOrderAmount\ValidationMessage
      */
-    private $validationMessages;
+    private $minimumAmountErrorMessage;
 
     /**
      * @param \Magento\Quote\Api\CartRepositoryInterface $quoteRepository
@@ -114,7 +114,7 @@ public function assign($cartId, \Magento\Quote\Api\Data\AddressInterface $addres
         $address->setCollectShippingRates(true);
 
         if (!$quote->validateMinimumAmount($quote->getIsMultiShipping())) {
-            throw new InputException($this->getMinimumAmountErrorMessageDependency()->getMessage());
+            throw new InputException($this->getMinimumAmountErrorMessage()->getMessage());
         }
 
         try {
@@ -144,15 +144,16 @@ public function get($cartId)
 
     /**
      * @return \Magento\Quote\Model\Quote\Validator\MinimumOrderAmount\ValidationMessage
+     * @deprecated
      */
-    private function getMinimumAmountErrorMessageDependency()
+    private function getMinimumAmountErrorMessage()
     {
-        if ($this->validationMessages === null) {
+        if ($this->minimumAmountErrorMessage === null) {
             $objectManager = ObjectManager::getInstance();
-            $this->validationMessages = $objectManager->get(
+            $this->minimumAmountErrorMessage = $objectManager->get(
                 \Magento\Quote\Model\Quote\Validator\MinimumOrderAmount\ValidationMessage::class
             );
         }
-        return $this->validationMessages;
+        return $this->minimumAmountErrorMessage;
     }
 }

app/code/Magento/Quote/Test/Unit/Model/Quote/Validator/MinimumOrderAmount/ValidationMessageTest.php

@@ -77,4 +77,15 @@ public function testGetMessage()
             $this->model->getMessage()
         );
     }
+
+    public function testGetConfigMessage()
+    {
+        $configMessage = 'config_message';
+        $this->scopeConfigMock->expects($this->once())
+            ->method('getValue')
+            ->with('sales/minimum_order/description', \Magento\Store\Model\ScopeInterface::SCOPE_STORE)
+            ->willReturn($configMessage);
+
+        $this->assertEquals($configMessage, $this->model->getMessage());
+    }
 }