fix(jsonapi): handle missing attributes in ErrorNormalizer

src/JsonApi/Serializer/ErrorNormalizer.php

@@ -35,7 +35,7 @@ public function __construct(private ?NormalizerInterface $itemNormalizer = null)
     public function normalize(mixed $object, ?string $format = null, array $context = []): array
     {
         $jsonApiObject = $this->itemNormalizer->normalize($object, $format, $context);
-        $error = $jsonApiObject['data']['attributes'];
+        $error = $jsonApiObject['data']['attributes'] ?? [];
         $error['id'] = $jsonApiObject['data']['id'];
         if (isset($error['type'])) {
             $error['links'] = ['type' => $error['type']];
@@ -45,6 +45,11 @@ public function normalize(mixed $object, ?string $format = null, array $context
             $error['code'] = $object->getId();
         }
 
+        // TODO: change this 5.x
+        // if (isset($error['status'])) {
+        //     $error['status'] = (string) $error['status'];
+        // }
+
         if (!isset($error['violations'])) {
             return ['errors' => [$error]];
         }

tests/Fixtures/TestBundle/ApiResource/JsonApiErrorTestResource.php

@@ -0,0 +1,44 @@
+<?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\Tests\Fixtures\TestBundle\ApiResource;
+
+use ApiPlatform\Metadata\Exception\ItemNotFoundException;
+use ApiPlatform\Metadata\Get;
+use ApiPlatform\Metadata\Operation;
+
+#[Get(
+    uriTemplate: '/jsonapi_error_test/{id}',
+    provider: [self::class, 'provide'],
+    formats: ['jsonapi' => ['application/vnd.api+json']],
+)]
+class JsonApiErrorTestResource
+{
+    public string $id;
+    public string $name;
+
+    public static function provide(Operation $operation, array $uriVariables = [], array $context = []): object|array|null
+    {
+        $id = $uriVariables['id'] ?? null;
+
+        if ('existing' === $id) {
+            $resource = new self();
+            $resource->id = $id;
+            $resource->name = 'Existing Resource';
+
+            return $resource;
+        }
+
+        throw new ItemNotFoundException(\sprintf('Resource "%s" not found.', $id));
+    }
+}

tests/Functional/JsonApiTest.php

@@ -0,0 +1,52 @@
+<?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\Tests\Functional;
+
+use ApiPlatform\Symfony\Bundle\Test\ApiTestCase;
+use ApiPlatform\Tests\Fixtures\TestBundle\ApiResource\JsonApiErrorTestResource;
+use ApiPlatform\Tests\SetupClassResourcesTrait;
+
+class JsonApiTest extends ApiTestCase
+{
+    use SetupClassResourcesTrait;
+    protected static ?bool $alwaysBootKernel = false;
+
+    /**
+     * @return class-string[]
+     */
+    public static function getResources(): array
+    {
+        return [
+            JsonApiErrorTestResource::class,
+        ];
+    }
+
+    public function testError(): void
+    {
+        self::createClient()->request('GET', '/jsonapi_error_test/nonexistent', [
+            'headers' => ['accept' => 'application/vnd.api+json'],
+        ]);
+
+        $this->assertResponseStatusCodeSame(400);
+        $this->assertResponseHeaderSame('content-type', 'application/vnd.api+json; charset=utf-8');
+        $this->assertJsonContains([
+            'errors' => [
+                [
+                    'status' => '400',
+                    'detail' => 'Resource "nonexistent" not found.',
+                ],
+            ],
+        ]);
+    }
+}