B2B-2258: Add caching capability to the storeConfig GraphQl query

Author: joanhe

app/code/Magento/StoreGraphQl/Model/Cache/Tag/Strategy/StoreConfig.php

@@ -0,0 +1,34 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+declare(strict_types=1);
+
+namespace Magento\StoreGraphQl\Model\Cache\Tag\Strategy;
+
+use Magento\Config\App\Config\Type\System;
+use Magento\Framework\App\Cache\Tag\StrategyInterface;
+use Magento\Framework\App\Config\ValueInterface;
+
+/**
+ * Produce cache tags for store config.
+ */
+class StoreConfig implements StrategyInterface
+{
+    /**
+     * @inheritdoc
+     */
+    public function getTags($object): array
+    {
+        if (!is_object($object)) {
+            throw new \InvalidArgumentException('Provided argument is not an object');
+        }
+
+        if ($object instanceof ValueInterface && $object->isValueChanged()) {
+            return [System::CACHE_TAG];
+        }
+
+        return [];
+    }
+}

app/code/Magento/StoreGraphQl/Model/Resolver/Store/Identity.php

@@ -7,26 +7,23 @@
 
 namespace Magento\StoreGraphQl\Model\Resolver\Store;
 
+use Magento\Config\App\Config\Type\System;
 use Magento\Framework\GraphQl\Query\Resolver\IdentityInterface;
-use Magento\Framework\App\Config;
 
 class Identity implements IdentityInterface
 {
     /**
      * @var string
      */
-    private $cacheTag = Config::CACHE_TAG;
+    private $cacheTag = System::CACHE_TAG;
 
     /**
      * @inheritDoc
      */
     public function getIdentities(array $resolvedData): array
     {
-        $data["id"] =  empty($resolvedData) ? [] : $resolvedData["id"];
         $ids =  empty($resolvedData) ?
-            [] : array_merge([$this->cacheTag], array_map(function ($key) {
-                return sprintf('%s_%s', $this->cacheTag, $key);
-            }, $data));
+            [] : [$this->cacheTag];
         return $ids;
     }
 }

app/code/Magento/StoreGraphQl/etc/di.xml

@@ -0,0 +1,16 @@
+<?xml version="1.0"?>
+<!--
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+-->
+<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:ObjectManager/etc/config.xsd">
+    <type name="Magento\Framework\App\Cache\Tag\Strategy\Factory">
+        <arguments>
+            <argument name="customStrategies" xsi:type="array">
+                <item name="Magento\Framework\App\Config\ValueInterface" xsi:type="object">Magento\StoreGraphQl\Model\Cache\Tag\Strategy\StoreConfig</item>
+            </argument>
+        </arguments>
+    </type>
+</config>