Graphql products query returns only ids for select or multiselect fields

app/code/Magento/CatalogGraphQl/Model/Product/Attributes/Collection.php

@@ -0,0 +1,137 @@
+<?php
+
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+
+declare(strict_types=1);
+
+namespace Magento\CatalogGraphQl\Model\Product\Attributes;
+
+use Magento\CatalogGraphQl\Model\Resolver\Products\Attributes\Collection as AttributesCollection;
+use Magento\CatalogGraphQl\Model\Resolver\Products\DataProvider\Product as ProductDataProvider;
+use Magento\Eav\Model\Entity\Attribute\Frontend\DefaultFrontend;
+use Magento\Framework\Api\SearchCriteriaBuilder;
+use Magento\Framework\Phrase;
+
+/**
+ * Collection for fetching custom attributes for products in filter.
+ */
+class Collection
+{
+    /**
+     * @var int[]
+     */
+    private $productIds = [];
+
+    /**
+     * @var array
+     */
+    private $attributeValueMap = [];
+
+    /**
+     * @var AttributesCollection
+     */
+    private $attributesCollection;
+
+    /**
+     * @var ProductDataProvider
+     */
+    private $productDataProvider;
+
+    /**
+     * @var SearchCriteriaBuilder
+     */
+    private $searchCriteriaBuilder;
+
+    /**
+     * @var DefaultFrontend
+     */
+    private $frontend;
+
+    /**
+     * @param AttributesCollection $attributesCollection
+     * @param ProductDataProvider $productDataProvider
+     * @param SearchCriteriaBuilder $searchCriteriaBuilder
+     * @param DefaultFrontend $frontend
+     */
+    public function __construct(
+        AttributesCollection $attributesCollection,
+        ProductDataProvider $productDataProvider,
+        SearchCriteriaBuilder $searchCriteriaBuilder,
+        DefaultFrontend $frontend
+    ) {
+        $this->attributesCollection = $attributesCollection;
+        $this->productDataProvider = $productDataProvider;
+        $this->searchCriteriaBuilder = $searchCriteriaBuilder;
+        $this->frontend = $frontend;
+    }
+
+    /**
+     * Add product id to attribute collection filter.
+     *
+     * @param int $productId
+     */
+    public function addProductId(int $productId): void
+    {
+        if (!in_array($productId, $this->productIds)) {
+            $this->productIds[] = $productId;
+        }
+    }
+
+    /**
+     * Retrieve attributes values for given product id or empty array
+     *
+     * @param int $productId
+     * @return array
+     */
+    public function getAttributesValueByProductId(int $productId): array
+    {
+        $attributes = $this->fetch();
+        if (!isset($attributes[$productId])) {
+            return [];
+        }
+
+        return $attributes[$productId];
+    }
+
+    /**
+     * Fetch attribute data
+     *
+     * @return array
+     */
+    private function fetch(): array
+    {
+        if (empty($this->productIds) || !empty($this->attributeValueMap)) {
+            return $this->attributeValueMap;
+        }
+
+        $attributes = $this->attributesCollection->getAttributes();
+
+        $this->searchCriteriaBuilder->addFilter('entity_id', $this->productIds, 'in');
+        $products = $this->productDataProvider->getList(
+            $this->searchCriteriaBuilder->create(),
+            ['*'],
+            false,
+            true
+        )->getItems();
+
+        foreach ($products as $productId => $product) {
+            $data = [];
+            foreach ($attributes as $attribute) {
+                $value = $this->frontend->setAttribute($attribute)->getValue($product);
+                if ($value instanceof Phrase) {
+                    $value = (string) $value;
+                }
+                $value = $value ? $value : null;
+                $data[] = [
+                    'value' => $value,
+                    'code' => $attribute->getAttributeCode(),
+                ];
+            }
+            $this->attributeValueMap[$productId] = $data;
+        }
+        return $this->attributeValueMap;
+    }
+}

app/code/Magento/CatalogGraphQl/Model/Resolver/Product/CustomAttributes.php

@@ -0,0 +1,63 @@
+<?php
+
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+
+declare(strict_types=1);
+
+namespace Magento\CatalogGraphQl\Model\Resolver\Product;
+
+use Magento\Framework\Exception\LocalizedException;
+use Magento\Framework\GraphQl\Schema\Type\ResolveInfo;
+use Magento\Framework\GraphQl\Config\Element\Field;
+use Magento\Framework\GraphQl\Query\ResolverInterface;
+use Magento\CatalogGraphQl\Model\Product\Attributes\Collection as AttributesCollection;
+use Magento\Framework\GraphQl\Query\Resolver\ValueFactory;
+
+/**
+ * Retrieves CustomAttributes
+ */
+class CustomAttributes implements ResolverInterface
+{
+    /**
+     * @var AttributesCollection
+     */
+    private $attributesCollection;
+
+    /**
+     * @var ValueFactory
+     */
+    private $valueFactory;
+
+    /**
+     * @param AttributesCollection $attributesCollection
+     * @param ValueFactory $valueFactory
+     */
+    public function __construct(
+        AttributesCollection $attributesCollection,
+        ValueFactory $valueFactory
+    ) {
+        $this->attributesCollection = $attributesCollection;
+        $this->valueFactory = $valueFactory;
+    }
+
+    /**
+     * @inheritdoc
+     */
+    public function resolve(Field $field, $context, ResolveInfo $info, array $value = null, array $args = null)
+    {
+        if (!isset($value['model'])) {
+            throw new LocalizedException(__('"model" value should be specified'));
+        }
+        $product = $value['model'];
+
+        $this->attributesCollection->addProductId((int)$product->getId());
+        $productId = $product->getId();
+        $result = function () use ($productId) {
+            return $this->attributesCollection->getAttributesValueByProductId((int)$productId);
+        };
+        return $this->valueFactory->create($result);
+    }
+}

app/code/Magento/CatalogGraphQl/etc/schema.graphqls

@@ -123,6 +123,12 @@ interface ProductInterface @typeResolver(class: "Magento\\CatalogGraphQl\\Model\
     categories: [CategoryInterface] @doc(description: "The categories assigned to a product.") @resolver(class: "Magento\\CatalogGraphQl\\Model\\Resolver\\Categories") @cache(cacheIdentity: "Magento\\CatalogGraphQl\\Model\\Resolver\\Category\\CategoriesIdentity")
     canonical_url: String @doc(description: "The relative canonical URL. This value is returned only if the system setting 'Use Canonical Link Meta Tag For Products' is enabled.") @resolver(class: "Magento\\CatalogGraphQl\\Model\\Resolver\\Product\\CanonicalUrl")
     media_gallery: [MediaGalleryInterface] @doc(description: "An array of media gallery objects.") @resolver(class: "Magento\\CatalogGraphQl\\Model\\Resolver\\Product\\MediaGallery")
+    custom_attributes: [CustomAttribute] @doc(description: "An array of custom product attributes.") @resolver(class: "Magento\\CatalogGraphQl\\Model\\Resolver\\Product\\CustomAttributes")
+}
+
+type CustomAttribute {
+    code: String! 
+    value: String 
 }
 
 interface PhysicalProductInterface @typeResolver(class: "Magento\\CatalogGraphQl\\Model\\ProductInterfaceTypeResolverComposite") @doc(description: "Contains attributes specific to tangible products.") {

dev/tests/api-functional/testsuite/Magento/GraphQl/Catalog/ProductsWithCustomAttributesTest.php

@@ -0,0 +1,106 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+declare (strict_types = 1);
+
+namespace Magento\GraphQl\Catalog;
+
+use Magento\TestFramework\TestCase\GraphQlAbstract;
+
+/**
+ * Test class for product with custom attributes
+ */
+class ProductsWithCustomAttributesTest extends GraphQlAbstract
+{
+    /**
+     * @magentoApiDataFixture Magento/Catalog/_files/products_with_multiselect_attribute.php
+     */
+    public function testQueryProductWithMultiSelectCustomAttribute()
+    {
+        if (!$this->cleanCache()) {
+            $this->fail('Cache could not be cleaned properly.');
+        }
+
+        $multiSelectAttribute = "multiselect_attribute";
+        $value = 'Option 2, Option 3, Option 4 "!@#$%^&*';
+        $query = <<<QUERY
+{
+  products(filter: {sku: {eq: "simple_ms_2" }}) {
+    items {
+      name
+      custom_attributes{
+        code
+        value
+      }
+    }
+  }
+}
+QUERY;
+        $response = $this->graphQlQuery($query);
+        $this->assertArrayHasKey('products', $response);
+        $this->assertArrayHasKey('items', $response['products']);
+        $this->assertCount(1, $response['products']['items']);
+        $this->assertArrayHasKey(0, $response['products']['items']);
+        $this->assertArrayHasKey('custom_attributes', $response['products']['items'][0]);
+        $customAttributes = $response['products']['items'][0]['custom_attributes'];
+        $this->assertCustomAttribute($customAttributes, $multiSelectAttribute, $value);
+    }
+
+    /**
+     * @magentoApiDataFixture Magento/Catalog/_files/product_simple_with_custom_attribute.php
+     */
+    public function testQueryProductWithTextCustomAttribute()
+    {
+        if (!$this->cleanCache()) {
+            $this->fail('Cache could not be cleaned properly.');
+        }
+        $prductSku = 'simple';
+        $textAttribute = "attribute_code_custom";
+        $value = 'customAttributeValue';
+        $query = <<<QUERY
+{
+    products(filter: {sku: {eq: "{$prductSku}"}})
+    {
+        items
+        {
+            custom_attributes{
+                code
+                value
+              }
+        }
+    }
+}
+QUERY;
+
+        $response = $this->graphQlQuery($query);
+        $this->assertArrayHasKey('products', $response);
+        $this->assertArrayHasKey('items', $response['products']);
+        $this->assertCount(1, $response['products']['items']);
+        $this->assertArrayHasKey(0, $response['products']['items']);
+        $this->assertArrayHasKey('custom_attributes', $response['products']['items'][0]);
+        $customAttributes = $response['products']['items'][0]['custom_attributes'];
+        $this->assertCustomAttribute($customAttributes, $textAttribute, $value);
+    }
+
+    /**
+     * @param array $customAttributes
+     * @param string $searchAttribute
+     * @param string $actualValue
+     */
+    private function assertCustomAttribute($customAttributes, $searchAttribute, $actualValue)
+    {
+        $flag = false;
+        $customAttributeValue = "";
+        foreach ($customAttributes as $attributes) {
+            if ($attributes['code'] == $searchAttribute) {
+                $flag = true;
+                $customAttributeValue = $attributes['value'];
+                break;
+            }
+        }
+        $this->assertStringContainsString($actualValue, $customAttributeValue);
+        $this->assertEquals(true, $flag);
+    }
+}