ACP2E-889: Wrong value of grand total on order refunds which contain discount

Author: Anna Bukatar

app/code/Magento/Sales/Model/Order/Creditmemo/Total/Tax.php

@@ -31,7 +31,8 @@ public function __construct(ResourceInvoice $resourceInvoice, array $data = [])
     }
 
     /**
-     * {@inheritdoc}
+     * @inheritdoc
+     *
      * @SuppressWarnings(PHPMD.NPathComplexity)
      * @SuppressWarnings(PHPMD.CyclomaticComplexity)
      * @SuppressWarnings(PHPMD.ExcessiveMethodLength)
@@ -104,7 +105,9 @@ public function collect(Creditmemo $creditmemo)
                 $baseShippingTaxAmount = $creditmemo->roundPrice($baseShippingTaxAmount, 'base');
                 $totalDiscountTaxCompensation = $creditmemo->roundPrice($totalDiscountTaxCompensation);
                 $baseTotalDiscountTaxCompensation = $creditmemo->roundPrice($baseTotalDiscountTaxCompensation, 'base');
-                if ($taxFactor < 1 && $invoice->getShippingTaxAmount() > 0) {
+                if ($taxFactor < 1 && $invoice->getShippingTaxAmount() > 0 ||
+                    ($order->getShippingDiscountAmount() >= $order->getShippingAmount())
+                ) {
                     $isPartialShippingRefunded = true;
                 }
                 $totalTax += $shippingTaxAmount;
@@ -136,7 +139,9 @@ public function collect(Creditmemo $creditmemo)
                     $baseShippingDiscountTaxCompensationAmount,
                     'base'
                 );
-                if ($part < 1 && $order->getShippingTaxAmount() > 0) {
+                if ($part < 1 && ($order->getShippingTaxAmount() > 0 ||
+                        ($order->getShippingDiscountAmount() >= $order->getShippingAmount()))
+                ) {
                     $isPartialShippingRefunded = true;
                 }
             } elseif ($shippingDelta == $creditmemo->getBaseShippingAmount()) {
@@ -187,7 +192,6 @@ public function collect(Creditmemo $creditmemo)
             $creditmemo->getBaseGrandTotal() + $baseTotalTax + $baseTotalDiscountTaxCompensation
         );
         return $this;
-
     }
 
     /**

app/code/Magento/Sales/Test/Unit/Model/Order/Creditmemo/Total/TaxTest.php

@@ -744,6 +744,68 @@ public function collectDataProvider()
             ],
         ];
 
+        // scenario 7: 1 items, 1 invoiced, rowtotal of  with 8.25 tax rate
+        // shipping is partially returned
+        $result['last_creditmemo_with_discount_for_entire_shipping_all_prices_including_tax'] = [
+            'order_data' => [
+                'data_fields' => [
+                    'shipping_tax_amount' => 0,
+                    'base_shipping_tax_amount' => 0,
+                    'shipping_discount_tax_compensation_amount' => 1.36,
+                    'base_shipping_discount_tax_compensation_amount' => 1.36,
+                    'tax_amount' => 1.22,
+                    'base_tax_amount' => 1.22,
+                    'tax_invoiced' => 1.22,
+                    'base_tax_invoiced' => 1.22,
+                    'shipping_amount' => 13.64,
+                    'shipping_discount_amount' => 15,
+                    'base_shipping_amount' => 13.64,
+                    'discount_tax_compensation_invoiced' => 1.73,
+                    'base_discount_tax_compensation_invoiced' => 1.73
+                ],
+            ],
+            'creditmemo_data' => [
+                'items' => [
+                    'item_1' => [
+                        'order_item' => [
+                            'qty_invoiced' => 1,
+                            'tax_invoiced' => 1.22,
+                            'base_tax_invoiced' => 1.22,
+                            'discount_tax_compensation_amount' => 1.73,
+                            'base_discount_tax_compensation_amount' => 1.73,
+                            'discount_tax_compensation_invoiced' => 1.73,
+                            'base_discount_tax_compensation_invoiced' => 1.73
+                        ],
+                        'is_last' => true,
+                        'qty' => 1,
+                    ],
+                ],
+                'is_last' => true,
+                'data_fields' => [
+                    'shipping_amount' => 0,
+                    'base_shipping_amount' => 0,
+                    'grand_total' => 10.45,
+                    'base_grand_total' => 10.45,
+                    'tax_amount' => 0,
+                    'base_tax_amount' => 0
+                ],
+            ],
+            'expected_results' => [
+                'creditmemo_items' => [
+                    'item_1' => [
+                        'tax_amount' => 1.22,
+                        'base_tax_amount' => 1.22,
+                    ],
+                ],
+                'creditmemo_data' => [
+                    'grand_total' => 13.4,
+                    'base_grand_total' => 13.4,
+                    'tax_amount' => 1.22,
+                    'base_tax_amount' => 1.22,
+                ],
+            ],
+        ];
+
         return $result;
     }