MAGETWO-72280: [Backport] Tier price saving percentage wrong when VAT is included in price #8833 2.1.x

Author: interio-zz

app/code/Magento/Bundle/Pricing/Price/TierPrice.php

@@ -7,7 +7,6 @@
 namespace Magento\Bundle\Pricing\Price;
 
 use Magento\Catalog\Pricing\Price\RegularPrice;
-use Magento\Framework\Pricing\Amount\AmountInterface;
 
 /**
  * Bundle tier prices model
@@ -90,13 +89,4 @@ public function isPercentageDiscount()
     {
         return true;
     }
-
-    /**
-     * @param AmountInterface $amount
-     * @return float
-     */
-    public function getSavePercent(AmountInterface $amount)
-    {
-        return round($amount->getBaseAmount());
-    }
 }

app/code/Magento/Bundle/Test/Unit/Pricing/Price/TierPriceTest.php

@@ -181,10 +181,27 @@ public function providerForGetterTierPriceList()
     /**
      * @dataProvider providerForTestGetSavePercent
      */
-    public function testGetSavePercent($baseAmount, $savePercent)
+    public function testGetSavePercent($baseAmount, $tierPrice, $savePercent)
     {
+        /** @var \Magento\Framework\Pricing\Amount\AmountInterface|\PHPUnit_Framework_MockObject_MockObject $amount */
         $amount = $this->getMockForAbstractClass('Magento\Framework\Pricing\Amount\AmountInterface');
-        $amount->expects($this->once())->method('getBaseAmount')->willReturn($baseAmount);
+        $amount->expects($this->any())
+            ->method('getValue')
+            ->will($this->returnValue($tierPrice));
+
+        $priceAmount = $this->getMockForAbstractClass('Magento\Framework\Pricing\Amount\AmountInterface');
+        $priceAmount->expects($this->any())
+            ->method('getValue')
+            ->will($this->returnValue($baseAmount));
+
+        $price = $this->getMock('Magento\Framework\Pricing\Price\PriceInterface');
+        $price->expects($this->any())
+            ->method('getAmount')
+            ->will($this->returnValue($priceAmount));
+
+        $this->priceInfo->expects($this->any())
+            ->method('getPrice')
+            ->will($this->returnValue($price));
 
         $this->assertEquals($savePercent, $this->model->getSavePercent($amount));
     }
@@ -195,10 +212,8 @@ public function testGetSavePercent($baseAmount, $savePercent)
     public function providerForTestGetSavePercent()
     {
         return [
-            'no fraction' => [10.0000, 10],
-            'lower half'  => [10.1234, 10],
-            'half way'    => [10.5000, 11],
-            'upper half'  => [10.6789, 11],
+            'no fraction' => [9.0000, 8.1, 10],
+            'lower half'  => [9.1234, 8.3, 9],
         ];
     }
 }

app/code/Magento/Catalog/Pricing/Price/TierPrice.php

@@ -203,14 +203,20 @@ protected function getBasePrice()
     }
 
     /**
+     * Calculates savings percentage according to the given tier price amount
+     * and related product price amount.
+     *
      * @param AmountInterface $amount
      * @return float
      */
     public function getSavePercent(AmountInterface $amount)
     {
-        return ceil(
-            100 - ((100 / $this->priceInfo->getPrice(FinalPrice::PRICE_CODE)->getValue())
-                * $amount->getBaseAmount())
+        $productPriceAmount = $this->priceInfo->getPrice(
+            FinalPrice::PRICE_CODE
+        )->getAmount();
+
+        return round(
+            100 - ((100 / $productPriceAmount->getValue()) * $amount->getValue())
         );
     }
 

app/code/Magento/Catalog/Test/Unit/Pricing/Price/TierPriceTest.php

@@ -10,6 +10,8 @@
 
 use Magento\Catalog\Pricing\Price\TierPrice;
 use Magento\Catalog\Pricing\Price\FinalPrice;
+use Magento\Framework\Pricing\Amount\AmountInterface;
+use Magento\Framework\Pricing\Price\PriceInterface;
 use Magento\Customer\Model\Group;
 use Magento\Customer\Model\GroupManagement;
 
@@ -361,27 +363,37 @@ public function providerForGetterTierPriceList()
     }
 
     /**
-     * @covers \Magento\Catalog\Pricing\Price\TierPrice::__construct
-     * @covers \Magento\Catalog\Pricing\Price\TierPrice::getSavePercent
-     * @covers \Magento\Catalog\Pricing\Price\TierPrice::getBasePrice
+     * @param float $basePrice
+     * @param float $tierPrice
+     * @param float $savedPercent
+     *
      * @dataProvider dataProviderGetSavePercent
      */
     public function testGetSavePercent($basePrice, $tierPrice, $savedPercent)
     {
-        $price = $this->getMock('Magento\Framework\Pricing\Price\PriceInterface');
+        /** @var AmountInterface|\PHPUnit_Framework_MockObject_MockObject $amount */
+        $amount = $this->getMockForAbstractClass(AmountInterface::class);
 
-        $this->priceInfo->expects(static::atLeastOnce())
-            ->method('getPrice')
-            ->with(FinalPrice::PRICE_CODE)
-            ->willReturn($price);
-        $price->expects(static::atLeastOnce())
+        $amount->expects($this->any())
+            ->method('getValue')
+            ->willReturn($tierPrice);
+
+        $basePriceAmount = $this->getMockForAbstractClass(AmountInterface::class);
+
+        $basePriceAmount->expects($this->any())
             ->method('getValue')
             ->willReturn($basePrice);
 
-        $amount = $this->getMockForAbstractClass('Magento\Framework\Pricing\Amount\AmountInterface');
-        $amount->expects($this->atLeastOnce())
-            ->method('getBaseAmount')
-            ->will($this->returnValue($tierPrice));
+        $price = $this->getMockForAbstractClass(PriceInterface::class);
+
+        $price->expects($this->any())
+            ->method('getAmount')
+            ->willReturn($basePriceAmount);
+
+        $this->priceInfo->expects($this->any())
+            ->method('getPrice')
+            ->with(FinalPrice::PRICE_CODE)
+            ->willReturn($price);
 
         $this->assertEquals($savedPercent, $this->model->getSavePercent($amount));
     }