magento · lbajsarowicz · Sep 4, 2026
diff --git a/app/code/Magento/CatalogInventoryGraphQl/Model/Resolver/OnlyXLeftInStockResolver.php b/app/code/Magento/CatalogInventoryGraphQl/Model/Resolver/OnlyXLeftInStockResolver.php
@@ -9,9 +9,11 @@
 
 use Magento\Catalog\Api\Data\ProductInterface;
 use Magento\Catalog\Api\ProductRepositoryInterface;
+use Magento\Catalog\Model\Product;
 use Magento\CatalogInventory\Api\StockRegistryInterface;
 use Magento\CatalogInventory\Model\Configuration;
 use Magento\Framework\App\Config\ScopeConfigInterface;
+use Magento\Framework\DataObject;
 use Magento\Framework\Exception\LocalizedException;
 use Magento\Framework\GraphQl\Schema\Type\ResolveInfo;
 use Magento\Framework\GraphQl\Config\Element\Field;
@@ -49,31 +51,55 @@ public function resolve(Field $field, $context, ResolveInfo $info, ?array $value
             throw new LocalizedException(__('"model" value should be specified'));
         }
 
-        $product = $value['model'];
-        if ($product->getTypeId() === self::PRODUCT_TYPE_CONFIGURABLE) {
-            $variant = $this->productRepositoryInterface->get($product->getSku());
-            return $this->getOnlyXLeftQty($variant);
+        $thresholdQty = (float)$this->scopeConfig->getValue(
+            Configuration::XML_PATH_STOCK_THRESHOLD_QTY,
+            ScopeInterface::SCOPE_STORE
+        );
+        if ($thresholdQty === 0.0) {
+            return null;
+        }
+
+        return $this->getOnlyXLeftQty($this->getConfiguredProduct($value['model']), $thresholdQty);
+    }
+
+    /**
+     * Get the product the stock data belongs to
+     *
+     * @param ProductInterface $product
+     * @return ProductInterface
+     * @throws LocalizedException
+     */
+    private function getConfiguredProduct(ProductInterface $product): ProductInterface
+    {
+        if ($product->getTypeId() !== self::PRODUCT_TYPE_CONFIGURABLE || !$product instanceof Product) {
+            return $product;
+        }
+
+        // A configurable cart item carries the selected child in the "simple_product" custom option, which is also
+        // what Configurable::getSku() reports; outside a cart item there is no such option and no variant to resolve.
+        $option = $product->getCustomOption('simple_product');
+        $variant = $option instanceof DataObject ? $option->getProduct() : null;
+        if ($variant instanceof ProductInterface) {
+            return $variant;
         }
-        return $this->getOnlyXLeftQty($product);
+
+        if ($product->getSku() !== $product->getData('sku')) {
+            return $this->productRepositoryInterface->get($product->getSku());
+        }
+
+        return $product;
     }
 
     /**
      * Get product qty left when "Catalog > Inventory > Stock Options > Only X left Threshold" is greater than 0
      *
      * @param ProductInterface $product
+     * @param float $thresholdQty
      *
      * @return null|float
      */
-    private function getOnlyXLeftQty(ProductInterface $product): ?float
+    private function getOnlyXLeftQty(ProductInterface $product, float $thresholdQty): ?float
     {
-        $thresholdQty = (float)$this->scopeConfig->getValue(
-            Configuration::XML_PATH_STOCK_THRESHOLD_QTY,
-            ScopeInterface::SCOPE_STORE
-        );
-        if ($thresholdQty === 0.0) {
-            return null;
-        }
-
         $stockItem = $this->stockRegistry->getStockItem($product->getId());
 
         $stockCurrentQty = $this->stockRegistry->getStockStatus(

diff --git a/app/code/Magento/CatalogInventoryGraphQl/Model/Resolver/StockStatus.php b/app/code/Magento/CatalogInventoryGraphQl/Model/Resolver/StockStatus.php
@@ -0,0 +1,127 @@
+<?php
+/**
+ * Copyright 2026 Adobe
+ * All Rights Reserved.
+ */
+declare(strict_types=1);
+
+namespace Magento\CatalogInventoryGraphQl\Model\Resolver;
+
+use Magento\Catalog\Api\Data\ProductInterface;
+use Magento\CatalogInventory\Api\StockConfigurationInterface;
+use Magento\CatalogInventory\Model\StockRegistryPreloader;
+use Magento\Framework\Exception\LocalizedException;
+use Magento\Framework\GraphQl\Config\Element\Field;
+use Magento\Framework\GraphQl\Query\Resolver\BatchRequestItemInterface;
+use Magento\Framework\GraphQl\Query\Resolver\BatchResolverInterface;
+use Magento\Framework\GraphQl\Query\Resolver\BatchResponse;
+use Magento\Framework\GraphQl\Query\Resolver\ContextInterface;
+use Magento\Quote\Model\Quote\Item;
+
+/**
+ * Resolve the stock status of all products of a single response with one stock status query.
+ */
+class StockStatus implements BatchResolverInterface
+{
+    /**
+     * In Stock return code
+     */
+    private const IN_STOCK = "IN_STOCK";
+
+    /**
+     * Out of Stock return code
+     */
+    private const OUT_OF_STOCK = "OUT_OF_STOCK";
+
+    /**
+     * @param StockRegistryPreloader $stockRegistryPreloader
+     * @param StockConfigurationInterface $stockConfiguration
+     * @param StockStatusProvider $stockStatusProvider
+     */
+    public function __construct(
+        private readonly StockRegistryPreloader $stockRegistryPreloader,
+        private readonly StockConfigurationInterface $stockConfiguration,
+        private readonly StockStatusProvider $stockStatusProvider
+    ) {
+    }
+
+    /**
+     * @inheritdoc
+     */
+    public function resolve(ContextInterface $context, Field $field, array $requests): BatchResponse
+    {
+        $productIds = [];
+        foreach ($requests as $request) {
+            if (!$this->isCartItemRequest($request)) {
+                $productIds[] = (int)$this->getProduct($request)->getId();
+            }
+        }
+
+        $stockStatuses = [];
+        if ($productIds) {
+            $preloaded = $this->stockRegistryPreloader->preloadStockStatuses(
+                array_values(array_unique($productIds)),
+                (int)$this->stockConfiguration->getDefaultScopeId()
+            );
+            foreach ($preloaded as $stockStatus) {
+                $stockStatuses[(int)$stockStatus->getProductId()] = (int)$stockStatus->getStockStatus();
+            }
+        }
+
+        $response = new BatchResponse();
+        foreach ($requests as $request) {
+            if ($this->isCartItemRequest($request)) {
+                $response->addResponse(
+                    $request,
+                    $this->stockStatusProvider->resolve(
+                        $field,
+                        $context,
+                        $request->getInfo(),
+                        $request->getValue(),
+                        $request->getArgs()
+                    )
+                );
+                continue;
+            }
+
+            $productId = (int)$this->getProduct($request)->getId();
+            $response->addResponse(
+                $request,
+                empty($stockStatuses[$productId]) ? self::OUT_OF_STOCK : self::IN_STOCK
+            );
+        }
+
+        return $response;
+    }
+
+    /**
+     * Get the product a request has been made for
+     *
+     * @param BatchRequestItemInterface $request
+     * @return ProductInterface
+     * @throws LocalizedException
+     */
+    private function getProduct(BatchRequestItemInterface $request): ProductInterface
+    {
+        $value = $request->getValue() ?? [];
+        if (!array_key_exists('model', $value) || !$value['model'] instanceof ProductInterface) {
+            throw new LocalizedException(__('"model" value should be specified'));
+        }
+
+        return $value['model'];
+    }
+
+    /**
+     * Cart items keep their own stock status semantics and are delegated to the single-item resolver
+     *
+     * @param BatchRequestItemInterface $request
+     * @return bool
+     * @throws LocalizedException
+     */
+    private function isCartItemRequest(BatchRequestItemInterface $request): bool
+    {
+        $this->getProduct($request);
+
+        return ($request->getValue()['cart_item'] ?? null) instanceof Item;
+    }
+}
diff --git a/...Magento/CatalogInventoryGraphQl/Test/Unit/Model/Resolver/OnlyXLeftInStockResolverTest.php b/...Magento/CatalogInventoryGraphQl/Test/Unit/Model/Resolver/OnlyXLeftInStockResolverTest.php
@@ -9,14 +9,15 @@
 
 use PHPUnit\Framework\TestCase;
 use PHPUnit\Framework\MockObject\MockObject;
+use Magento\Catalog\Api\ProductRepositoryInterface;
 use Magento\CatalogInventoryGraphQl\Model\Resolver\OnlyXLeftInStockResolver;
 use Magento\Framework\App\Config\ScopeConfigInterface;
 use Magento\Framework\GraphQl\Config\Element\Field;
 use Magento\GraphQl\Model\Query\ContextInterface;
-use Magento\Framework\TestFramework\Unit\Helper\ObjectManager;
 use Magento\Framework\GraphQl\Schema\Type\ResolveInfo;
 use Magento\CatalogInventory\Api\StockRegistryInterface;
 use Magento\Catalog\Model\Product;
+use Magento\Quote\Model\Quote\Item\Option;
 use Magento\Store\Api\Data\StoreInterface;
 use Magento\CatalogInventory\Api\Data\StockItemInterface;
 use Magento\CatalogInventory\Api\Data\StockStatusInterface;
@@ -26,13 +27,6 @@
  */
 class OnlyXLeftInStockResolverTest extends TestCase
 {
-    /**
-     * Object Manager Instance
-     *
-     * @var ObjectManager
-     */
-    private $objectManager;
-
     /**
      * Testable Object
      *
@@ -65,6 +59,11 @@ class OnlyXLeftInStockResolverTest extends TestCase
      */
     private $stockRegistryMock;
 
+    /**
+     * @var ProductRepositoryInterface|MockObject
+     */
+    private $productRepositoryMock;
+
     /**
      * @var Product|MockObject
      */
@@ -91,14 +90,13 @@ class OnlyXLeftInStockResolverTest extends TestCase
 
     protected function setUp(): void
     {
-        $this->objectManager = new ObjectManager($this);
-
         $this->contextMock = $this->createMock(ContextInterface::class);
         $this->fieldMock = $this->createMock(Field::class);
         $this->resolveInfoMock = $this->createMock(ResolveInfo::class);
         $this->productModelMock = $this->createMock(Product::class);
         $this->scopeConfigMock = $this->createMock(ScopeConfigInterface::class);
         $this->stockRegistryMock = $this->createMock(StockRegistryInterface::class);
+        $this->productRepositoryMock = $this->createMock(ProductRepositoryInterface::class);
         $this->storeMock = $this->createMock(StoreInterface::class);
         $this->stockItemMock = $this->createMock(StockItemInterface::class);
         $this->stockStatusMock = $this->createMock(StockStatusInterface::class);
@@ -110,12 +108,10 @@ protected function setUp(): void
             ->willReturn($this->stockStatusMock);
         $this->storeMock->expects($this->atMost(1))->method('getWebsiteId')->willReturn(1);
 
-        $this->resolver = $this->objectManager->getObject(
-            OnlyXLeftInStockResolver::class,
-            [
-                'scopeConfig' => $this->scopeConfigMock,
-                'stockRegistry' => $this->stockRegistryMock
-            ]
+        $this->resolver = new OnlyXLeftInStockResolver(
+            $this->scopeConfigMock,
+            $this->stockRegistryMock,
+            $this->productRepositoryMock
         );
     }
 
@@ -174,6 +170,8 @@ public function testResolveNoThresholdQty()
         $this->stockItemMock->expects($this->never())->method('getMinQty');
         $this->stockStatusMock->expects($this->never())->method('getQty');
         $this->stockRegistryMock->expects($this->never())->method('getStockItem');
+        $this->productRepositoryMock->expects($this->never())->method('get');
+        $this->productModelMock->expects($this->never())->method('getTypeId');
         $this->scopeConfigMock->method('getValue')->willReturn($thresholdQty);
 
         $this->assertEquals(
@@ -186,4 +184,57 @@ public function testResolveNoThresholdQty()
             )
         );
     }
+
+    public function testResolveConfigurableWithoutSelectedVariant()
+    {
+        $this->scopeConfigMock->method('getValue')->willReturn(200);
+        $this->productModelMock->method('getTypeId')->willReturn('configurable');
+        $this->productModelMock->method('getCustomOption')->with('simple_product')->willReturn(null);
+        $this->productModelMock->method('getSku')->willReturn('parent_configurable');
+        $this->productModelMock->method('getData')->with('sku')->willReturn('parent_configurable');
+        $this->productRepositoryMock->expects($this->never())->method('get');
+        $this->stockRegistryMock->expects($this->once())->method('getStockItem')->with(1)
+            ->willReturn($this->stockItemMock);
+        $this->stockItemMock->method('getMinQty')->willReturn(0);
+        $this->stockStatusMock->method('getQty')->willReturn(100);
+
+        $this->assertEquals(
+            100,
+            $this->resolver->resolve(
+                $this->fieldMock,
+                $this->contextMock,
+                $this->resolveInfoMock,
+                ['model' => $this->productModelMock]
+            )
+        );
+    }
+
+    public function testResolveConfigurableUsesSimpleProductOption()
+    {
+        $variantMock = $this->createMock(Product::class);
+        $variantMock->method('getId')->willReturn(42);
+        $variantMock->method('getStore')->willReturn($this->storeMock);
+
+        $optionMock = $this->createMock(Option::class);
+        $optionMock->method('getProduct')->willReturn($variantMock);
+
+        $this->scopeConfigMock->method('getValue')->willReturn(200);
+        $this->productModelMock->method('getTypeId')->willReturn('configurable');
+        $this->productModelMock->method('getCustomOption')->with('simple_product')->willReturn($optionMock);
+        $this->productRepositoryMock->expects($this->never())->method('get');
+        $this->stockRegistryMock->expects($this->once())->method('getStockItem')->with(42)
+            ->willReturn($this->stockItemMock);
+        $this->stockItemMock->method('getMinQty')->willReturn(0);
+        $this->stockStatusMock->method('getQty')->willReturn(7);
+
+        $this->assertEquals(
+            7,
+            $this->resolver->resolve(
+                $this->fieldMock,
+                $this->contextMock,
+                $this->resolveInfoMock,
+                ['model' => $this->productModelMock]
+            )
+        );
+    }
 }