Add extension attributes sample code

Author: shochdoerfer

magento/composer.json

@@ -21,6 +21,8 @@
         "cweagans/composer-patches": "^1.7",
         "magento/composer-dependency-version-audit-plugin": "~0.1",
         "magento/composer-root-update-plugin": "~2.0",
+        "magento/module-catalog": "^104.0",
+        "magento/module-inventory-api": "^1.2",
         "magento/product-community-edition": "2.4.5",
         "swissup/module-search-mysql-legacy": "^1.1",
         "yireo/magento2-replace-all": "^4.2"

src/BitExpert_PHPStanTests/Helper/TestExtAttributes.php

@@ -0,0 +1,29 @@
+<?php
+
+declare(strict_types=1);
+
+namespace BitExpert\PHPStanTests\Helper;
+
+/**
+ * Test Extension attributes
+ */
+class TestExtAttributes
+{
+    public function __construct(
+        \Magento\Catalog\Api\Data\ProductExtension $productExt,
+        \Magento\InventoryApi\Api\Data\StockExtension $stockExt
+    )
+    {
+        // access extension attributes defined in extension_attributes.xml in the module
+        $productExt->setAdditionalName('Additional name');
+        $name = $productExt->getAdditionalName();
+        $productExt->setAdditionalId(99);
+        $id = $productExt->getAdditionalId();
+
+        $stockExt->setSalesChannels(null);
+        $channels = $stockExt->getSalesChannels();
+
+        // access extension attribute defined in Magento_CatalogInventory
+        $stockItem = $productExt->getStockItem();
+    }
+}

src/BitExpert_PHPStanTests/composer.json

@@ -4,7 +4,9 @@
   "license": "Apache-2.0",
   "require": {
     "php": "~8.1.0",
-    "magento/framework": "~103.0.5"
+    "magento/framework": "~103.0.5",
+    "magento/module-inventory-api": "^1.2",
+    "magento/module-catalog": "^104.0"
   },
   "repositories": [
     {

src/BitExpert_PHPStanTests/etc/extension_attributes.xml

@@ -0,0 +1,10 @@
+<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:Api/etc/extension_attributes.xsd">
+    <extension_attributes for="Magento\Catalog\Api\Data\ProductInterface">
+        <attribute code="additional_name" type="string"/>
+        <attribute code="additional_id" type="int"/>
+    </extension_attributes>
+
+    <extension_attributes for="Magento\InventoryApi\Api\Data\StockInterface">
+        <attribute code="sales_channels" type="Magento\InventorySalesApi\Api\Data\SalesChannelInterface[]" />
+    </extension_attributes>
+</config>