[Serializer] Fixed BackedEnumNormalizer priority for translatable enum

src/Symfony/Bundle/FrameworkBundle/Resources/config/serializer.php

@@ -219,6 +219,6 @@
             ])
 
         ->set('serializer.normalizer.backed_enum', BackedEnumNormalizer::class)
-            ->tag('serializer.normalizer', ['priority' => -915])
+            ->tag('serializer.normalizer', ['priority' => -880])
     ;
 };

src/Symfony/Bundle/FrameworkBundle/Tests/Fixtures/TranslatableBackedEnum.php

@@ -0,0 +1,27 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Bundle\FrameworkBundle\Tests\Fixtures;
+
+use Symfony\Contracts\Translation\TranslatableInterface;
+use Symfony\Contracts\Translation\TranslatorInterface;
+
+enum TranslatableBackedEnum: string implements TranslatableInterface
+{
+    case Get = 'GET';
+
+    public function trans(TranslatorInterface $translator, ?string $locale = null): string
+    {
+        return match ($this) {
+            self::Get => 'custom_get_string',
+        };
+    }
+}

src/Symfony/Bundle/FrameworkBundle/Tests/Functional/SerializerTest.php

@@ -11,6 +11,8 @@
 
 namespace Symfony\Bundle\FrameworkBundle\Tests\Functional;
 
+use Symfony\Bundle\FrameworkBundle\Tests\Fixtures\TranslatableBackedEnum;
+
 /**
  * @author Kévin Dunglas <dunglas@gmail.com>
  */
@@ -67,6 +69,15 @@ public static function provideNormalizersAndEncodersWithDefaultContextOption():
             ['serializer.encoder.csv.alias'],
         ];
     }
+
+    public function testSerializeTranslatableBackedEnum()
+    {
+        static::bootKernel(['test_case' => 'Serializer']);
+
+        $serializer = static::getContainer()->get('serializer.alias');
+
+        $this->assertEquals('GET', $serializer->serialize(TranslatableBackedEnum::Get, 'yaml'));
+    }
 }
 
 class Foo