ACP2E-1992: Configurable on sale products not visible in products carousel

- added unit tests

Author: aplapana

app/code/Magento/ConfigurableProduct/Test/Unit/Plugin/CatalogWidget/Block/Product/ProductListPluginTest.php

@@ -0,0 +1,115 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+declare(strict_types=1);
+
+namespace Magento\ConfigurableProduct\Test\Unit\Plugin\CatalogWidget\Block\Product;
+
+use Magento\Catalog\Model\Product\Visibility;
+use Magento\Catalog\Model\ResourceModel\Product\Collection;
+use Magento\Catalog\Model\ResourceModel\Product\CollectionFactory;
+use Magento\CatalogWidget\Block\Product\ProductsList;
+use Magento\ConfigurableProduct\Plugin\CatalogWidget\Block\Product\ProductsListPlugin;
+use Magento\Framework\App\ResourceConnection;
+use Magento\Framework\DB\Adapter\AdapterInterface;
+use PHPUnit\Framework\TestCase;
+use PHPUnit\Framework\MockObject\MockObject;
+use Magento\Framework\DB\Select;
+use Magento\Framework\DataObject;
+
+class ProductListPluginTest extends TestCase
+{
+    /**
+     * @var CollectionFactory|MockObject
+     */
+    protected CollectionFactory $productCollectionFactory;
+
+    /**
+     * @var Visibility|MockObject
+     */
+    protected Visibility $catalogProductVisibility;
+
+    /**
+     * @var ResourceConnection|MockObject
+     */
+    protected ResourceConnection $resource;
+
+    /**
+     * @var ProductsListPlugin
+     */
+    protected ProductsListPlugin $plugin;
+
+    protected function setUp(): void
+    {
+        $this->productCollectionFactory = $this->createMock(CollectionFactory::class);
+        $this->catalogProductVisibility = $this->createMock(Visibility::class);
+        $this->resource = $this->createMock(ResourceConnection::class);
+
+        $this->plugin = new ProductsListPlugin(
+            $this->productCollectionFactory,
+            $this->catalogProductVisibility,
+            $this->resource
+        );
+
+        parent::setUp();
+    }
+
+    /**
+     * @return void
+     * @throws \Magento\Framework\Exception\LocalizedException
+     */
+    public function testAfterCreateCollectionNoCount(): void
+    {
+        $subject = $this->createMock(ProductsList::class);
+        $result = $this->createMock(Collection::class);
+        $result->expects($this->once())->method('count')->willReturn(0);
+
+        $this->assertSame($result, $this->plugin->afterCreateCollection($subject, $result));
+    }
+
+    /**
+     * @return void
+     * @throws \Magento\Framework\Exception\LocalizedException
+     */
+    public function testAfterCreateCollectionSuccess(): void
+    {
+        $subject = $this->createMock(ProductsList::class);
+        $result = $this->createMock(Collection::class);
+        $result->expects($this->once())->method('count')->willReturn(1);
+        $result->expects($this->once())->method('getAllIds')->willReturn([1]);
+        $result->expects($this->once())->method('addItem');
+
+        $select = $this->createMock(Select::class);
+        $select->expects($this->once())
+            ->method('from')
+            ->with(['e' => 'catalog_product_entity'], ['link_table.parent_id'])
+            ->willReturn($select);
+        $select->expects($this->once())
+            ->method('joinInner')
+            ->with(
+                ['link_table' => 'catalog_product_super_link'],
+                'link_table.product_id = e.entity_id',
+                []
+            )->willReturn($select);
+        $select->expects($this->once())->method('where')->with('link_table.product_id IN (?)', [1]);
+        $connection = $this->createMock(AdapterInterface::class);
+        $connection->expects($this->once())->method('select')->willReturn($select);
+        $connection->expects($this->once())->method('fetchCol')->willReturn([2]);
+        $this->resource->expects($this->once())->method('getConnection')->willReturn($connection);
+        $this->resource->expects($this->exactly(2))
+            ->method('getTableName')
+            ->withConsecutive(['catalog_product_entity'], ['catalog_product_super_link'])
+            ->willReturnOnConsecutiveCalls('catalog_product_entity', 'catalog_product_super_link');
+
+        $collection = $this->createMock(Collection::class);
+        $this->productCollectionFactory->expects($this->once())->method('create')->willReturn($collection);
+        $this->catalogProductVisibility->expects($this->once())->method('getVisibleInCatalogIds');
+        $collection->expects($this->once())->method('setVisibility');
+        $collection->expects($this->once())->method('addIdFilter');
+        $collection->expects($this->once())->method('getItems')->willReturn([new DataObject()]);
+
+        $this->plugin->afterCreateCollection($subject, $result);
+    }
+}