fix(doctrine): guard unmapped relation links in ORM handleLinks

src/Doctrine/Orm/State/LinksHandlerTrait.php

@@ -88,6 +88,13 @@ private function handleLinks(QueryBuilder $queryBuilder, array $identifiers, Que
             $joinProperties = $doctrineClassMetadata->getIdentifierFieldNames();
 
             if ($link->getFromProperty() && !$link->getToProperty()) {
+                // The link was built from the property's native type (LinkFactory), but the
+                // property may not be a mapped Doctrine association (e.g. a transient,
+                // resource-typed self reference). There is nothing to join on, skip it.
+                if (!$fromClassMetadata->hasAssociation($link->getFromProperty())) {
+                    continue;
+                }
+
                 $joinAlias = $queryNameGenerator->generateJoinAlias('m');
                 $associationMapping = $fromClassMetadata->getAssociationMapping($link->getFromProperty()); // @phpstan-ignore-line
                 $relationType = $associationMapping['type'];

src/Doctrine/Orm/Tests/State/ItemProviderTest.php

@@ -282,6 +282,7 @@ public function testGetSubresourceFromProperty(): void
         $queryBuilderMock->expects($this->once())->method('setParameter')->with('id_p1', 1, Types::INTEGER);
 
         $employeeClassMetadataMock = $this->createMock(ClassMetadata::class);
+        $employeeClassMetadataMock->method('hasAssociation')->with('company')->willReturn(true);
         $employeeClassMetadataMock->method('getAssociationMapping')->with('company')->willReturn(
             class_exists(ManyToOneAssociationMapping::class) ?
                 new ManyToOneAssociationMapping('company', Employee::class, Company::class) :

tests/Fixtures/TestBundle/Entity/GraphQlTransientSelfReference/TransientSelfReference.php

@@ -0,0 +1,46 @@
+<?php
+
+/*
+ * This file is part of the API Platform project.
+ *
+ * (c) Kévin Dunglas <dunglas@gmail.com>
+ *
+ * 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\Tests\Fixtures\TestBundle\Entity\GraphQlTransientSelfReference;
+
+use ApiPlatform\Metadata\ApiResource;
+use ApiPlatform\Metadata\GraphQl\Query;
+use Doctrine\ORM\Mapping as ORM;
+
+#[ApiResource(graphQlOperations: [new Query()])]
+#[ORM\Entity]
+class TransientSelfReference
+{
+    #[ORM\Id]
+    #[ORM\Column(type: 'integer')]
+    #[ORM\GeneratedValue(strategy: 'AUTO')]
+    public ?int $id = null;
+
+    #[ORM\Column(type: 'string')]
+    public ?string $name = null;
+
+    // Typed as the resource class but NOT a Doctrine association: a transient,
+    // runtime-only self reference. LinkFactory builds a relation link from the
+    // native type, but the ORM has no association mapping to join on.
+    private ?self $relatedButNotMapped = null;
+
+    public function getRelatedButNotMapped(): ?self
+    {
+        return $this->relatedButNotMapped;
+    }
+
+    public function setRelatedButNotMapped(?self $related): void
+    {
+        $this->relatedButNotMapped = $related;
+    }
+}

tests/Functional/GraphQl/TransientSelfReferenceTest.php

@@ -0,0 +1,82 @@
+<?php
+
+/*
+ * This file is part of the API Platform project.
+ *
+ * (c) Kévin Dunglas <dunglas@gmail.com>
+ *
+ * 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\Tests\Functional\GraphQl;
+
+use ApiPlatform\Symfony\Bundle\Test\ApiTestCase;
+use ApiPlatform\Tests\Fixtures\TestBundle\Entity\GraphQlTransientSelfReference\TransientSelfReference;
+use ApiPlatform\Tests\RecreateSchemaTrait;
+use ApiPlatform\Tests\SetupClassResourcesTrait;
+
+/**
+ * A GraphQL item query must not crash when the resource has a public property
+ * typed as the resource class but not mapped as a Doctrine association. The
+ * relation link built from the native type has no association mapping to join
+ * on, so the ORM LinksHandlerTrait must skip it instead of throwing
+ * "No mapping found for field ... on class ...".
+ *
+ * @see https://github.com/api-platform/core/issues/8292
+ */
+final class TransientSelfReferenceTest extends ApiTestCase
+{
+    use RecreateSchemaTrait;
+    use SetupClassResourcesTrait;
+
+    protected static ?bool $alwaysBootKernel = false;
+
+    /**
+     * @return class-string[]
+     */
+    public static function getResources(): array
+    {
+        return [TransientSelfReference::class];
+    }
+
+    public function testItemQueryWithTransientResourceTypedPropertyDoesNotCrash(): void
+    {
+        if ($this->isMongoDB()) {
+            $this->markTestSkipped('TransientSelfReference is ORM-only.');
+        }
+
+        $this->recreateSchema([TransientSelfReference::class]);
+
+        $manager = $this->getManager();
+        $first = new TransientSelfReference();
+        $first->name = 'First';
+        $manager->persist($first);
+        $second = new TransientSelfReference();
+        $second->name = 'Second';
+        $manager->persist($second);
+        $manager->flush();
+
+        // Query the second item: proves the identifier-self link still applies
+        // WHERE id=X after the unmapped relation link is skipped.
+        $iri = '/transient_self_references/'.$second->id;
+
+        $response = self::createClient()->request('POST', '/graphql', ['json' => [
+            'query' => <<<GRAPHQL
+            {
+              transientSelfReference(id: "{$iri}") {
+                id
+                name
+              }
+            }
+            GRAPHQL,
+        ]]);
+
+        $this->assertResponseIsSuccessful();
+        $json = $response->toArray(false);
+        $this->assertArrayNotHasKey('errors', $json, json_encode($json['errors'] ?? null));
+        $this->assertSame('Second', $json['data']['transientSelfReference']['name']);
+    }
+}