Fixing bug with non-existent customer group breaking quote

app/code/Magento/Checkout/Test/Mftf/Test/OnePageCheckoutAsCustomerUsingNonExistentCustomerGroupTest.xml

@@ -0,0 +1,116 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+ /**
+  * Copyright © Magento, Inc. All rights reserved.
+  * See COPYING.txt for license details.
+  */
+-->
+
+<tests xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+       xsi:noNamespaceSchemaLocation="urn:magento:mftf:Test/etc/testSchema.xsd">
+    <test name="OnePageCheckoutAsCustomerUsingNonExistentCustomerGroupTest">
+        <annotations>
+            <features value="OnePageCheckout"/>
+            <stories value="OnePageCheckout within Offline Payment Methods"/>
+            <title value="OnePageCheckout as a customer with non-existent customer group assigned to the quote"/>
+            <description value="Checkout as a customer with non-existent customer group assigned to the quote"/>
+            <severity value="AVERAGE"/>
+            <testCaseId value="MC-36385"/>
+            <group value="checkout"/>
+        </annotations>
+        <before>
+            <!-- Create Simple Product -->
+            <createData entity="SimpleProduct2" stepKey="createSimpleProduct">
+                <field key="price">560</field>
+            </createData>
+
+            <!-- Create customer group -->
+            <createData entity="CustomCustomerGroup" stepKey="createCustomerGroup"/>
+
+            <!-- Create customer and assign it to the customer group created on the previous step -->
+            <createData entity="Simple_US_Customer_Multiple_Addresses" stepKey="createCustomer">
+                <field key="group_id">$$createCustomerGroup.id$$</field>
+            </createData>
+        </before>
+        <after>
+            <!-- Admin log out -->
+            <actionGroup ref="AdminLogoutActionGroup" stepKey="logout"/>
+
+            <!-- Customer log out -->
+            <actionGroup ref="StorefrontCustomerLogoutActionGroup" stepKey="customerLogout"/>
+
+            <!-- Delete created product -->
+            <deleteData createDataKey="createSimpleProduct" stepKey="deleteSimpleProduct"/>
+
+            <!-- Delete customer -->
+            <deleteData createDataKey="createCustomer" stepKey="deleteCustomer"/>
+        </after>
+
+        <!-- Login as customer -->
+        <actionGroup ref="LoginToStorefrontActionGroup" stepKey="customerLogin">
+            <argument name="Customer" value="$$createCustomer$$"/>
+        </actionGroup>
+
+        <!-- Add Simple Product to cart -->
+        <amOnPage url="{{StorefrontProductPage.url($$createSimpleProduct.custom_attributes[url_key]$$)}}" stepKey="navigateToSimpleProductPage"/>
+        <waitForPageLoad stepKey="waitForSimpleProductPageLoad"/>
+        <actionGroup ref="AddToCartFromStorefrontProductPageActionGroup" stepKey="addToCartFromStorefrontProductPage">
+            <argument name="productName" value="$$createSimpleProduct.name$$"/>
+        </actionGroup>
+
+        <!-- Delete customer group -->
+        <deleteData createDataKey="createCustomerGroup" stepKey="deleteCustomerGroup"/>
+
+        <!-- Go to shopping cart -->
+        <actionGroup ref="ClickViewAndEditCartFromMiniCartActionGroup" stepKey="goToShoppingCartFromMinicart"/>
+        <actionGroup ref="FillShippingZipForm" stepKey="fillShippingZipForm">
+            <argument name="address" value="US_Address_CA"/>
+        </actionGroup>
+        <click selector="{{CheckoutCartSummarySection.proceedToCheckout}}" stepKey="clickProceedToCheckout"/>
+        <waitForPageLoad stepKey="waitForProceedToCheckout"/>
+
+        <!-- Check that error does not appear and shipping methods are available to select -->
+        <dontSee selector="{{CheckoutCartMessageSection.errorMessage}}" userInput="No such entity with id = $$createCustomerGroup.id$$" stepKey="assertErrorMessage"/>
+        <dontSee selector="{{CheckoutShippingMethodsSection.noQuotesMsg}}" userInput="Sorry, no quotes are available for this order at this time" stepKey="assertNoQuotesMessage"/>
+
+        <!-- Fill customer address data -->
+        <waitForElementVisible selector="{{CheckoutShippingSection.shipHereButton(UK_Not_Default_Address.street[0])}}" stepKey="waitForShipHereVisible"/>
+        <!-- Change address -->
+        <click selector="{{CheckoutShippingSection.shipHereButton(UK_Not_Default_Address.street[0])}}" stepKey="clickShipHere"/>
+
+        <!-- Click next button to open payment section -->
+        <click selector="{{CheckoutShippingGuestInfoSection.next}}" stepKey="clickNext"/>
+        <waitForPageLoad stepKey="waitForShipmentPageLoad"/>
+
+        <!-- Select payment solution -->
+        <checkOption selector="{{CheckoutPaymentSection.billingAddressNotSameCheckbox}}" stepKey="selectPaymentSolution" />
+
+        <!-- Check order summary in checkout -->
+        <waitForElement selector="{{CheckoutPaymentSection.paymentSectionTitle}}" stepKey="waitForPaymentSectionLoaded"/>
+        <click selector="{{CheckoutPaymentSection.placeOrder}}" stepKey="clickPlaceOrderButton"/>
+        <seeElement selector="{{CheckoutSuccessMainSection.success}}" stepKey="orderIsSuccessfullyPlaced"/>
+        <grabTextFrom selector="{{CheckoutSuccessMainSection.orderNumber22}}" stepKey="grabOrderNumber"/>
+
+        <!-- Login as admin -->
+        <actionGroup ref="AdminLoginActionGroup" stepKey="loginAsAdmin"/>
+
+        <!-- Open created order in backend -->
+        <amOnPage url="{{AdminOrdersPage.url}}" stepKey="goToOrders"/>
+        <waitForPageLoad stepKey="waitForOrdersPageLoad"/>
+        <actionGroup ref="OpenOrderByIdActionGroup" stepKey="filterOrderGridById">
+            <argument name="orderId" value="$grabOrderNumber"/>
+        </actionGroup>
+
+        <!-- Assert order total -->
+        <scrollTo selector="{{AdminOrderTotalSection.grandTotal}}" stepKey="scrollToOrderTotalSection"/>
+        <see selector="{{AdminOrderTotalSection.grandTotal}}" userInput="$565.00" stepKey="checkOrderTotalInBackend"/>
+
+        <!-- Assert order addresses -->
+        <see selector="{{AdminShipmentAddressInformationSection.billingAddress}}" userInput="{{UK_Not_Default_Address.street[0]}}" stepKey="seeBillingAddressStreet"/>
+        <see selector="{{AdminShipmentAddressInformationSection.billingAddress}}" userInput="{{UK_Not_Default_Address.city}}" stepKey="seeBillingAddressCity"/>
+        <see selector="{{AdminShipmentAddressInformationSection.billingAddress}}" userInput="{{UK_Not_Default_Address.postcode}}" stepKey="seeBillingAddressPostcode"/>
+        <see selector="{{AdminShipmentAddressInformationSection.shippingAddress}}" userInput="{{UK_Not_Default_Address.street[0]}}" stepKey="seeShippingAddressStreet"/>
+        <see selector="{{AdminShipmentAddressInformationSection.shippingAddress}}" userInput="{{UK_Not_Default_Address.city}}" stepKey="seeShippingAddressCity"/>
+        <see selector="{{AdminShipmentAddressInformationSection.shippingAddress}}" userInput="{{UK_Not_Default_Address.postcode}}" stepKey="seeShippingAddressPostcode"/>
+    </test>
+</tests>

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

@@ -10,6 +10,7 @@
 use Magento\Directory\Model\AllowedCountries;
 use Magento\Framework\Api\AttributeValueFactory;
 use Magento\Framework\Api\ExtensionAttribute\JoinProcessorInterface;
+use Magento\Framework\Exception\NoSuchEntityException;
 use Magento\Framework\Model\AbstractExtensibleModel;
 use Magento\Quote\Api\Data\PaymentInterface;
 use Magento\Quote\Model\Quote\Address;
@@ -1104,7 +1105,22 @@ public function getCustomerTaxClassId()
         //if (!$this->getData('customer_group_id') && !$this->getData('customer_tax_class_id')) {
         $groupId = $this->getCustomerGroupId();
         if ($groupId !== null) {
-            $taxClassId = $this->groupRepository->getById($this->getCustomerGroupId())->getTaxClassId();
+            $taxClassId = null;
+            try {
+                $taxClassId = $this->groupRepository->getById($this->getCustomerGroupId())->getTaxClassId();
+            } catch (NoSuchEntityException $e) {
+                /**
+                 * A customer MAY create a quote and AFTER that customer group MAY be deleted.
+                 * That breaks a quote because it still refers no a non-existent customer group.
+                 * In such a case we should load a new customer group id from the current customer
+                 * object and use it to retrieve tax class and update quote.
+                 */
+                $groupId = $this->getCustomer()->getGroupId();
+                $this->setCustomerGroupId($groupId);
+                if ($groupId !== null) {
+                    $taxClassId = $this->groupRepository->getById($groupId)->getTaxClassId();
+                }
+            }
             $this->setCustomerTaxClassId($taxClassId);
         }
 

app/code/Magento/Quote/Test/Unit/Model/QuoteTest.php

@@ -30,7 +30,9 @@
 use Magento\Framework\DataObject\Copy;
 use Magento\Framework\DataObject\Factory;
 use Magento\Framework\Event\Manager;
+use Magento\Framework\Exception\NoSuchEntityException;
 use Magento\Framework\Model\Context;
+use Magento\Framework\Phrase;
 use Magento\Framework\TestFramework\Unit\Helper\ObjectManager;
 use Magento\Quote\Api\Data\CartInterface;
 use Magento\Quote\Model\Quote;
@@ -640,6 +642,48 @@ public function testGetCustomerTaxClassId()
         $this->assertEquals($taxClassId, $result);
     }
 
+    /**
+     * Test case when non-existent customer group is stored into the quote.
+     * In such a case we should get a NoSuchEntityException exception and try
+     * to get a valid customer group from the current customer object.
+     */
+    public function testGetCustomerTaxClassIdForNonExistentCustomerGroup()
+    {
+        $customerId = 1;
+        $nonExistentGroupId = 100;
+        $groupId = 1;
+        $taxClassId = 1;
+        $groupMock = $this->getMockForAbstractClass(GroupInterface::class, [], '', false);
+        $this->groupRepositoryMock->expects($this->at(0))
+            ->method('getById')
+            ->with($nonExistentGroupId)
+            ->willThrowException(new NoSuchEntityException(new Phrase('Entity Id does not exist')));
+        $customerMock = $this->getMockForAbstractClass(
+            CustomerInterface::class,
+            [],
+            '',
+            false
+        );
+        $customerMock->expects($this->once())
+            ->method('getGroupId')
+            ->willReturn($groupId);
+        $this->customerRepositoryMock->expects($this->once())
+            ->method('getById')
+            ->with($customerId)
+            ->willReturn($customerMock);
+        $this->groupRepositoryMock->expects($this->at(1))
+            ->method('getById')
+            ->with($groupId)
+            ->willReturn($groupMock);
+        $groupMock->expects($this->once())
+            ->method('getTaxClassId')
+            ->willReturn($taxClassId);
+        $this->quote->setData('customer_id', $customerId);
+        $this->quote->setData('customer_group_id', $nonExistentGroupId);
+        $result = $this->quote->getCustomerTaxClassId();
+        $this->assertEquals($taxClassId, $result);
+    }
+
     public function testGetAllAddresses()
     {
         $id = 1;