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

- configurable products are added to product widget result list if child products match rule

Author: aplapana

app/code/Magento/ConfigurableProduct/Plugin/CatalogWidget/Block/Product/ProductsListPlugin.php

@@ -0,0 +1,86 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+
+declare(strict_types=1);
+
+namespace Magento\ConfigurableProduct\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\Framework\App\ResourceConnection;
+use Magento\Framework\Exception\LocalizedException;
+
+class ProductsListPlugin
+{
+    /**
+     * @var CollectionFactory
+     */
+    protected CollectionFactory $productCollectionFactory;
+
+    /**
+     * @var Visibility
+     */
+    protected Visibility $catalogProductVisibility;
+
+    /**
+     * @var ResourceConnection
+     */
+    protected ResourceConnection $resource;
+
+    /**
+     * @param CollectionFactory $productCollectionFactory
+     * @param Visibility $catalogProductVisibility
+     * @param ResourceConnection $resource
+     */
+    public function __construct(
+        CollectionFactory  $productCollectionFactory,
+        Visibility         $catalogProductVisibility,
+        ResourceConnection $resource
+    ) {
+        $this->productCollectionFactory = $productCollectionFactory;
+        $this->catalogProductVisibility = $catalogProductVisibility;
+        $this->resource = $resource;
+    }
+
+    /**
+     * Adds configurable products to the item list if child products are already part of the collection
+     *
+     * @param ProductsList $subject
+     * @param Collection $result
+     * @return Collection
+     * @throws LocalizedException
+     * @SuppressWarnings(PHPMD.UnusedFormalParameter)
+     */
+    public function afterCreateCollection(ProductsList $subject, Collection $result): Collection
+    {
+        if ($result->count()) {
+            $connection = $this->resource->getConnection();
+            $productIds = $connection->fetchCol(
+                $connection
+                ->select()
+                ->from(['e' => $this->resource->getTableName('catalog_product_entity')], ['link_table.parent_id'])
+                ->joinInner(
+                    ['link_table' => $this->resource->getTableName('catalog_product_super_link')],
+                    'link_table.product_id = e.entity_id',
+                    []
+                )
+                ->where('link_table.product_id IN (?)', $result->getAllIds())
+            );
+
+            $configurableProductCollection = $this->productCollectionFactory->create();
+            $configurableProductCollection->setVisibility($this->catalogProductVisibility->getVisibleInCatalogIds());
+            $configurableProductCollection->addIdFilter($productIds);
+
+            foreach ($configurableProductCollection->getItems() as $item) {
+                $result->addItem($item);
+            }
+        }
+
+        return $result;
+    }
+}

app/code/Magento/ConfigurableProduct/etc/frontend/di.xml

@@ -23,4 +23,7 @@
             </argument>
         </arguments>
     </type>
+    <type name="Magento\CatalogWidget\Block\Product\ProductsList">
+        <plugin name="configurable_product_widget_product_list" type="Magento\ConfigurableProduct\Plugin\CatalogWidget\Block\Product\ProductsListPlugin" />
+    </type>
 </config>