ACP2E-3463: Invalid discount calculation with priority

Author: aplapana

app/code/Magento/SalesRule/Helper/CartFixedDiscount.php

@@ -1,6 +1,6 @@
 <?php
 /**
- * Copyright 2024 Adobe
+ * Copyright 2020 Adobe
  * All Rights Reserved.
  */
 declare(strict_types=1);

app/code/Magento/SalesRule/Test/Unit/Helper/CartFixedDiscountTest.php

@@ -0,0 +1,88 @@
+<?php
+/**
+ * Copyright 2024 Adobe
+ * All Rights Reserved.
+ */
+declare(strict_types=1);
+
+namespace Magento\SalesRule\Test\Unit\Helper;
+
+use Magento\Framework\App\Config\ScopeConfigInterface;
+use Magento\Framework\Pricing\PriceCurrencyInterface;
+use Magento\Quote\Model\Cart\ShippingMethodConverter;
+use Magento\SalesRule\Helper\CartFixedDiscount;
+use Magento\SalesRule\Model\DeltaPriceRound;
+use PHPUnit\Framework\TestCase;
+use PHPUnit\Framework\MockObject\MockObject;
+
+class CartFixedDiscountTest extends TestCase
+{
+    /**
+     * @var DeltaPriceRound|MockObject
+     */
+    private DeltaPriceRound $deltaPriceRound;
+
+    /**
+     * @var PriceCurrencyInterface|MockObject
+     */
+    private PriceCurrencyInterface $priceCurrency;
+
+    /**
+     * @var ShippingMethodConverter|MockObject
+     */
+    private ShippingMethodConverter $shippingMethodConverter;
+
+    /**
+     * @var ScopeConfigInterface|MockObject
+     */
+    private ScopeConfigInterface $scopeConfig;
+
+    /**
+     * @inhertidoc
+     */
+    protected function setUp(): void
+    {
+        parent::setUp();
+
+        $this->deltaPriceRound = $this->createMock(DeltaPriceRound::class);
+        $this->priceCurrency = $this->createMock(PriceCurrencyInterface::class);
+        $this->shippingMethodConverter = $this->createMock(ShippingMethodConverter::class);
+        $this->scopeConfig = $this->createMock(ScopeConfigInterface::class);
+    }
+
+    /**
+     * @return void
+     */
+    public function testGetDiscountedAmountProportionally(): void
+    {
+        $ruleDiscount = 5;
+        $qty = 2.0;
+        $baseItemPrice = 10.0;
+        $baseItemDiscountAmount = 0.0;
+        $baseRuleTotalsDiscount = 10;
+        $discountType = 'fixed';
+        $expected = 5.0;
+
+        $cartFixedDiscount = new CartFixedDiscount(
+            $this->deltaPriceRound,
+            $this->priceCurrency,
+            $this->shippingMethodConverter,
+            $this->scopeConfig
+        );
+        $this->deltaPriceRound->expects($this->once())
+            ->method('round')
+            ->with(5, $discountType)
+            ->willReturn($expected);
+        $this->assertSame(
+            $expected,
+            $cartFixedDiscount->getDiscountedAmountProportionally(
+                $ruleDiscount,
+                $qty,
+                $baseItemPrice,
+                $baseItemDiscountAmount,
+                $baseRuleTotalsDiscount,
+                $discountType
+            )
+        );
+    }
+}