fix(graphql): add unit test for interitance case

src/GraphQl/Tests/State/Provider/ResolverProviderTest.php

@@ -15,6 +15,9 @@
 
 use ApiPlatform\GraphQl\Resolver\QueryItemResolverInterface;
 use ApiPlatform\GraphQl\State\Provider\ResolverProvider;
+use ApiPlatform\GraphQl\Tests\Fixtures\ApiResource\ChildFoo;
+use ApiPlatform\GraphQl\Tests\Fixtures\ApiResource\ParentFoo;
+use ApiPlatform\Metadata\GraphQl\Query;
 use ApiPlatform\Metadata\GraphQl\QueryCollection;
 use ApiPlatform\State\ProviderInterface;
 use PHPUnit\Framework\TestCase;
@@ -35,4 +38,18 @@ public function testProvide(): void
         $provider = new ResolverProvider($decorated, $resolverLocator);
         $this->assertEquals($res, $provider->provide($operation, [], $context));
     }
+
+    public function testProvideInheritedClass(): void
+    {
+        $res = new ChildFoo();
+        $operation = new Query(class: ParentFoo::class, resolver: 'foo');
+        $context = [];
+        $decorated = $this->createMock(ProviderInterface::class);
+        $resolverMock = $this->createMock(QueryItemResolverInterface::class);
+        $resolverMock->expects($this->once())->method('__invoke')->willReturn($res);
+        $resolverLocator = $this->createMock(ContainerInterface::class);
+        $resolverLocator->expects($this->once())->method('get')->with('foo')->willReturn($resolverMock);
+        $provider = new ResolverProvider($decorated, $resolverLocator);
+        $this->assertEquals($res, $provider->provide($operation, [], $context));
+    }
 }