fix(graphql): item resolver inheritance error

src/GraphQl/Resolver/Factory/ItemResolverFactory.php

@@ -106,7 +106,7 @@ private function getResourceClass(?object $item, ?string $resourceClass, string
             return $itemClass;
         }
 
-        if ($resourceClass !== $itemClass) {
+        if ($resourceClass !== $itemClass && !$item instanceof $resourceClass) {
             throw new \UnexpectedValueException(sprintf($errorMessage, (new \ReflectionClass($resourceClass))->getShortName(), (new \ReflectionClass($itemClass))->getShortName()));
         }
 

src/GraphQl/Tests/Fixtures/ApiResource/ChildFoo.php

@@ -0,0 +1,18 @@
+<?php
+
+/*
+ * This file is part of the API Platform project.
+ *
+ * (c) Kévin Dunglas <[email protected]>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+declare(strict_types=1);
+
+namespace ApiPlatform\GraphQl\Tests\Fixtures\ApiResource;
+
+class ChildFoo extends ParentFoo
+{
+}

src/GraphQl/Tests/Fixtures/ApiResource/ParentFoo.php

@@ -0,0 +1,18 @@
+<?php
+
+/*
+ * This file is part of the API Platform project.
+ *
+ * (c) Kévin Dunglas <[email protected]>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+declare(strict_types=1);
+
+namespace ApiPlatform\GraphQl\Tests\Fixtures\ApiResource;
+
+class ParentFoo
+{
+}

src/GraphQl/Tests/Resolver/Factory/ItemResolverFactoryTest.php

@@ -18,7 +18,9 @@
 use ApiPlatform\GraphQl\Resolver\Stage\SecurityPostDenormalizeStageInterface;
 use ApiPlatform\GraphQl\Resolver\Stage\SecurityStageInterface;
 use ApiPlatform\GraphQl\Resolver\Stage\SerializeStageInterface;
+use ApiPlatform\GraphQl\Tests\Fixtures\ApiResource\ChildFoo;
 use ApiPlatform\GraphQl\Tests\Fixtures\ApiResource\Dummy;
+use ApiPlatform\GraphQl\Tests\Fixtures\ApiResource\ParentFoo;
 use ApiPlatform\Metadata\GraphQl\Query;
 use GraphQL\Type\Definition\ResolveInfo;
 use PHPUnit\Framework\TestCase;
@@ -245,4 +247,22 @@ public function testResolveCustomBadItem(): void
 
         ($this->itemResolverFactory)($resourceClass, $rootClass, $operation)($source, $args, null, $info);
     }
+
+    public function testResolveInheritedClass(): void
+    {
+        $resourceClass = ParentFoo::class;
+        $rootClass = $resourceClass;
+        $operationName = 'custom_query';
+        $operation = (new Query())->withName($operationName);
+        $source = ['source'];
+        $args = ['args'];
+        $info = $this->prophesize(ResolveInfo::class)->reveal();
+        $info->fieldName = 'field';
+        $resolverContext = ['source' => $source, 'args' => $args, 'info' => $info, 'is_collection' => false, 'is_mutation' => false, 'is_subscription' => false];
+
+        $readStageItem = new ChildFoo();
+        $this->readStageProphecy->__invoke($resourceClass, $rootClass, $operation, $resolverContext)->shouldBeCalled()->willReturn($readStageItem);
+
+        ($this->itemResolverFactory)($resourceClass, $rootClass, $operation)($source, $args, null, $info);
+    }
 }