ACP2E-3332: Issue sales rules with Fixed amount discount and "Maximum Qty Discount is Applied To"

Author: abukatar

app/code/Magento/SalesRule/Model/Rule/Action/Discount/ByFixed.php

@@ -27,8 +27,9 @@ public function calculate($rule, $item, $qty)
         $itemPrice = $this->validator->getItemPrice($item);
         $baseItemPrice = $this->validator->getItemBasePrice($item);
 
-        $discountAmountMin = min(($itemPrice * $qty) - $itemDiscountAmount, $discountAmount * $qty);
-        $baseDiscountAmountMin = min(($baseItemPrice * $qty) - $itemBaseDiscountAmount, $baseDiscountAmount * $qty);
+        $discountAmountMin = min(($itemPrice * $item->getQty()) - $itemDiscountAmount, $discountAmount * $qty);
+        $baseDiscountAmountMin =
+            min(($baseItemPrice * $item->getQty()) - $itemBaseDiscountAmount, $baseDiscountAmount * $qty);
 
         $discountData->setAmount($discountAmountMin);
         $discountData->setBaseAmount($baseDiscountAmountMin);

app/code/Magento/SalesRule/Model/Utility.php

@@ -147,8 +147,9 @@ public function minFix(
         $itemDiscountAmount = $item->getDiscountAmount();
         $itemBaseDiscountAmount = $item->getBaseDiscountAmount();
 
-        $discountAmount = min($itemDiscountAmount + $discountData->getAmount(), $itemPrice * $qty);
-        $baseDiscountAmount = min($itemBaseDiscountAmount + $discountData->getBaseAmount(), $baseItemPrice * $qty);
+        $discountAmount = min($itemDiscountAmount + $discountData->getAmount(), $itemPrice * $item->getQty());
+        $baseDiscountAmount =
+            min($itemBaseDiscountAmount + $discountData->getBaseAmount(), $baseItemPrice * $item->getQty());
 
         $discountData->setAmount($discountAmount);
         $discountData->setBaseAmount($baseDiscountAmount);

app/code/Magento/SalesRule/Test/Unit/Model/Rule/Action/Discount/ByFixedTest.php

@@ -123,9 +123,9 @@ public function testCalculate(
                     'getQuote',
                     'getAddress',
                     'getOptionByCode',
+                    'getQty'
                 ]
             )->getMock();
-
         $this->validator->expects(
             $this->atLeastOnce()
         )->method(
@@ -170,32 +170,12 @@ public function testCalculate(
         )->with(
             $ruleData['discountAmount'],
             $store
-        )->willReturn(
-            $validItemData['baseOriginalPrice']
-        );
-
-        $rule->expects(
-            $this->atLeastOnce()
-        )->method(
-            'getDiscountAmount'
         )->willReturn(
             $ruleData['discountAmount']
         );
 
-        $item->expects(
-            $this->atLeastOnce()
-        )->method(
-            'getDiscountAmount'
-        )->willReturn(
-            $itemData['discountAmount']
-        );
-        $item->expects(
-            $this->atLeastOnce()
-        )->method(
-            'getBaseDiscountAmount'
-        )->willReturn(
-            $itemData['baseDiscountAmount']
-        );
+        $this->setUpMockData($ruleData, $rule);
+        $this->setUpMockData($itemData, $item);
         $item->expects($this->atLeastOnce())->method('getQuote')->willReturn($quote);
 
         $discountData->expects($this->once())->method('setAmount')->with($expectedDiscountData['amount']);
@@ -218,6 +198,22 @@ public function testCalculate(
         $this->assertEquals($discountData, $this->model->calculate($rule, $item, $qty));
     }
 
+    /**
+     * Sets up mock object data
+     *
+     * @param array $data
+     * @param MockObject $mockObject
+     * @return void
+     */
+    private function setUpMockData(array $data, MockObject $mockObject): void
+    {
+        foreach ($data as $method => $returnValue) {
+            $mockObject->expects($this->atLeastOnce())
+                ->method('get' . ucfirst($method))
+                ->willReturn($returnValue);
+        }
+    }
+
     /**
      * @return array
      */
@@ -227,7 +223,7 @@ public function calculateDataProvider()
             [
                 'qty' => 2,
                 'ruleData' => ['discountAmount' => 100],
-                'itemData' => ['discountAmount' => 139, 'baseDiscountAmount' => 139],
+                'itemData' => ['discountAmount' => 139, 'baseDiscountAmount' => 139, 'qty' => 2],
                 'validItemData' => [
                     'price' => 139,
                     'basePrice' => 139,
@@ -240,6 +236,23 @@ public function calculateDataProvider()
                     'originalAmount' => 0,
                     'baseOriginalAmount' => 0,
                 ],
+            ],
+            [
+                'qty' => 1,
+                'ruleData' => ['discountAmount' => 1000],
+                'itemData' => ['discountAmount' => 9100, 'baseDiscountAmount' => 9100, 'qty' => 13],
+                'validItemData' => [
+                    'price' => 9000,
+                    'basePrice' => 9000,
+                    'originalPrice' => 9000,
+                    'baseOriginalPrice' => 9000,
+                ],
+                'expectedDiscountData' => [
+                    'amount' => 1000,
+                    'baseAmount' => 1000,
+                    'originalAmount' => 0,
+                    'baseOriginalAmount' => 0,
+                ],
             ]
         ];
     }

app/code/Magento/SalesRule/Test/Unit/Model/UtilityTest.php

@@ -426,6 +426,7 @@ public function testMinFix(): void
         $this->getItemBasePrice();
         $this->item->setDiscountAmount($amount);
         $this->item->setBaseDiscountAmount($baseAmount);
+        $this->item->setQty($qty);
         $discountData = $this->createMock(Data::class);
         $discountData->expects($this->atLeastOnce())
             ->method('getAmount')