magento#25675 Added Unit tests to test QuoteItemQtyList::getQty method

app/code/Magento/CatalogInventory/Test/Unit/Model/Quote/Item/QuantityValidator/QuoteItemQtyListTest.php

@@ -0,0 +1,64 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+
+namespace Magento\CatalogInventory\Test\Unit\Model\Quote\Item\QuantityValidator;
+
+use Magento\Framework\TestFramework\Unit\Helper\ObjectManager;
+use PHPUnit\Framework\TestCase;
+use Magento\CatalogInventory\Model\Quote\Item\QuantityValidator\QuoteItemQtyList;
+
+/**
+ * Class QuoteItemQtyListTest
+ */
+class QuoteItemQtyListTest extends TestCase
+{
+    /**
+     * @var QuoteItemQtyList
+     */
+    private $quoteItemQtyList;
+
+    /**
+     * @var int
+     */
+    private $itemQtyTestValue;
+
+    protected function setUp()
+    {
+        $objectManagerHelper = new ObjectManager($this);
+        $this->quoteItemQtyList = $objectManagerHelper->getObject(QuoteItemQtyList::class);
+    }
+
+    /**
+     * This tests the scenario when item has not quote_item_id and after save gets a value.
+     *
+     * @return void
+     */
+    public function testSingleQuoteItemQty()
+    {
+        $this->itemQtyTestValue = 1;
+        $qty = $this->quoteItemQtyList->getQty(125, null, 11232, 1);
+        $this->assertEquals($this->itemQtyTestValue, $qty);
+
+        $qty = $this->quoteItemQtyList->getQty(125, 1, 11232, 1);
+        $this->assertEquals($this->itemQtyTestValue, $qty);
+    }
+
+    /**
+     * This tests the scenario when item has been added twice to the cart.
+     *
+     * @return void
+     */
+    public function testMultipleQuoteItemQty()
+    {
+        $this->itemQtyTestValue = 1;
+        $qty = $this->quoteItemQtyList->getQty(127, 1, 112, 1);
+        $this->assertEquals($this->itemQtyTestValue, $qty);
+
+        $this->itemQtyTestValue = 2;
+        $qty = $this->quoteItemQtyList->getQty(127, 2, 112, 1);
+        $this->assertEquals($this->itemQtyTestValue, $qty);
+    }
+}