ENGCOM-6477: [Catalog] covered product ViewModel AddToCompareAvailability by Unit Test #26050

 - Merge Pull Request #26050 from srsathish92/magento2:2.4-unit-test/catalog-viewmodel-addtocompareavailability
 - Merged commits:
   1. f075d4e
   2. 0b806f9
   3. 97fe3ff
   4. 9e042b6
   5. a308d4a

Author: magento-engcom-team

app/code/Magento/Catalog/Test/Unit/ViewModel/Product/Checker/AddToCompareAvailabilityTest.php

@@ -0,0 +1,105 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+
+declare(strict_types=1);
+
+namespace Magento\Catalog\Test\Unit\ViewModel\Product\Checker;
+
+use Magento\Catalog\ViewModel\Product\Checker\AddToCompareAvailability;
+use Magento\CatalogInventory\Api\StockConfigurationInterface;
+use Magento\Catalog\Model\Product;
+use Magento\Catalog\Model\Product\Attribute\Source\Status;
+use Magento\Framework\TestFramework\Unit\Helper\ObjectManager;
+use PHPUnit\Framework\MockObject\MockObject;
+
+/**
+ * Unit test for Magento\Catalog\ViewModel\Product\Checker\AddToCompareAvailability.
+ */
+class AddToCompareAvailabilityTest extends \PHPUnit\Framework\TestCase
+{
+
+    /**
+     * @var AddToCompareAvailability
+     */
+    private $viewModel;
+
+    /**
+     * @var StockConfigurationInterface|MockObject
+     */
+    protected $stockConfigurationMock;
+
+    /**
+     * @inheritdoc
+     */
+    protected function setUp(): void
+    {
+
+        $objectManager = new ObjectManager($this);
+
+        $this->stockConfigurationMock =
+            $this->getMockBuilder(StockConfigurationInterface::class)
+            ->getMock();
+
+        $this->viewModel = $objectManager->getObject(
+            AddToCompareAvailability::class,
+            [
+                'stockConfiguration' => $this->stockConfigurationMock
+            ]
+        );
+    }
+
+    /**
+     * Test IsAvailableForCompare() with data provider
+     *
+     * @param bool $status
+     * @param bool $isSalable
+     * @param array $isInStock
+     * @param bool $isShowOutOfStock
+     * @param bool $expectedBool
+     * @return void
+     * @dataProvider isAvailableForCompareDataProvider
+     */
+    public function testIsAvailableForCompare($status, $isSalable, $isInStock, $isShowOutOfStock, $expectedBool): void
+    {
+        $productMock = $this->getMockBuilder(Product::class)
+            ->disableOriginalConstructor()
+            ->getMock();
+
+        $productMock->expects($this->once())
+            ->method('getStatus')
+            ->willReturn($status);
+
+        $productMock->expects($this->any())
+            ->method('isSalable')
+            ->willReturn($isSalable);
+
+        $productMock->expects($this->any())
+            ->method('getQuantityAndStockStatus')
+            ->willReturn($isInStock);
+
+        $this->stockConfigurationMock->expects($this->any())
+            ->method('isShowOutOfStock')
+            ->willReturn($isShowOutOfStock);
+
+        $this->assertEquals($expectedBool, $this->viewModel->isAvailableForCompare($productMock));
+    }
+
+    /**
+     * Data provider for isAvailableForCompare()
+     *
+     * @return array
+     */
+    public function isAvailableForCompareDataProvider(): array
+    {
+        return [
+            [Status::STATUS_ENABLED, true, ['is_in_stock' => true], false, true],
+            [Status::STATUS_ENABLED, true, ['is_in_stock' => false], true, true],
+            [Status::STATUS_ENABLED, true, [], false, true],
+            [Status::STATUS_ENABLED, false, [], false, false],
+            [Status::STATUS_DISABLED, true, ['is_in_stock' => true], false, false]
+        ];
+    }
+}