symfony · moinhussain · Apr 13, 2021 · Apr 15, 2021
diff --git a/src/Symfony/Component/Serializer/CHANGELOG.md b/src/Symfony/Component/Serializer/CHANGELOG.md
@@ -9,6 +9,7 @@ CHANGELOG
  * Add normalization formats to `UidNormalizer`
  * Add `CsvEncoder::END_OF_LINE` context option
  * Deprecate creating instances of the annotation classes by passing an array of parameters, use named arguments instead
+ * Added `BackedEnumNormalizer`
 
 5.2.0
 -----

diff --git a/src/Symfony/Component/Serializer/Normalizer/BackedEnumNormalizer.php b/src/Symfony/Component/Serializer/Normalizer/BackedEnumNormalizer.php
@@ -0,0 +1,73 @@
+<?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\Component\Serializer\Normalizer;
+
+use Symfony\Component\Serializer\Exception\NotNormalizableValueException;
+
+final class BackedEnumNormalizer implements NormalizerInterface, DenormalizerInterface, CacheableSupportsMethodInterface
+{
+    /**
+     * {@inheritdoc}
+     *
+     * @param \BackedEnum $object
+     */
+    public function normalize($object, string $format = null, array $context = [])
+    {
+        return $object->value;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function supportsNormalization($data, string $format = null)
+    {
+        if (version_compare(\PHP_VERSION, '8.1', '<')) {
+            return false;
+        }
+
+        return $data instanceof \BackedEnum;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function denormalize($data, string $type, string $format = null, array $context = [])
+    {
+        $denormalized = $type::tryFrom($data);
+
+        if (null === $denormalized) {
+            throw new NotNormalizableValueException(sprintf('The data is not a valid "%s" value.', $type));
+        }
+
+        return $denormalized;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function supportsDenormalization($data, string $type, string $format = null)
+    {
+        if (version_compare(\PHP_VERSION, '8.1', '<')) {
+            return false;
+        }
+
+        return is_a($type, \BackedEnum::class, true);
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function hasCacheableSupportsMethod(): bool
+    {
+        return __CLASS__ === static::class;
+    }
+}
diff --git a/src/Symfony/Component/Serializer/Tests/Fixtures/Normalizer/EnumBackedClassDummy.php b/src/Symfony/Component/Serializer/Tests/Fixtures/Normalizer/EnumBackedClassDummy.php
@@ -0,0 +1,22 @@
+<?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\Component\Serializer\Tests\Fixtures\Normalizer;
+
+class EnumBackedClassDummy
+{
+    public EnumBackedDummy $suit;
+
+    public function __construct(EnumBackedDummy $suit = null)
+    {
+        $this->suit = $suit;
+    }
+}
diff --git a/src/Symfony/Component/Serializer/Tests/Fixtures/Normalizer/EnumBackedDummy.php b/src/Symfony/Component/Serializer/Tests/Fixtures/Normalizer/EnumBackedDummy.php
@@ -0,0 +1,20 @@
+<?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\Component\Serializer\Tests\Fixtures\Normalizer;
+
+enum EnumBackedDummy: string
+{
+    case Hearts = 'H';
+    case Diamonds = 'D';
+    case Clubs = 'C';
+    case Spades = 'S';
+};
diff --git a/src/Symfony/Component/Serializer/Tests/Fixtures/Normalizer/EnumPureClassDummy.php b/src/Symfony/Component/Serializer/Tests/Fixtures/Normalizer/EnumPureClassDummy.php
@@ -0,0 +1,22 @@
+<?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\Component\Serializer\Tests\Fixtures\Normalizer;
+
+class EnumPureClassDummy
+{
+    public EnumPureDummy $suit;
+
+    public function __construct(EnumPureDummy $suit = null)
+    {
+        $this->suit = $suit;
+    }
+}
diff --git a/src/Symfony/Component/Serializer/Tests/Fixtures/Normalizer/EnumPureDummy.php b/src/Symfony/Component/Serializer/Tests/Fixtures/Normalizer/EnumPureDummy.php
@@ -0,0 +1,20 @@
+<?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\Component\Serializer\Tests\Fixtures\Normalizer;
+
+enum EnumPureDummy
+{
+    case Hearts;
+    case Diamonds;
+    case Clubs;
+    case Spades;
+};
diff --git a/src/Symfony/Component/Serializer/Tests/Normalizer/BackedEnumNormalizerTest.php b/src/Symfony/Component/Serializer/Tests/Normalizer/BackedEnumNormalizerTest.php
@@ -0,0 +1,84 @@
+<?php
+
+namespace Symfony\Component\Serializer\Tests\Normalizer;
+
+use PHPUnit\Framework\TestCase;
+use Symfony\Component\Serializer\Exception\NotNormalizableValueException;
+use Symfony\Component\Serializer\Normalizer\BackedEnumNormalizer;
+use Symfony\Component\Serializer\Tests\Fixtures\Normalizer\EnumBackedDummy;
+use Symfony\Component\Serializer\Tests\Fixtures\Normalizer\EnumPureDummy;
+
+class BackedEnumNormalizerTest extends TestCase
+{
+    /**
+     * @var BackedEnumNormalizer
+     */
+    private $normalizer;
+
+    protected function setUp(): void
+    {
+        $this->normalizer = new BackedEnumNormalizer();
+    }
+
+    /**
+     * @requires PHP >= 8.1
+     */
+    public function testSupportsNormalization()
+    {
+        $this->assertTrue($this->normalizer->supportsNormalization(EnumBackedDummy::Diamonds));
+        $this->assertFalse($this->normalizer->supportsNormalization(EnumPureDummy::Diamonds));
+        $this->assertFalse($this->normalizer->supportsNormalization(new \stdClass()));
+    }
+
+    /**
+     * @requires PHP < 8.1
+     */
+    public function testSupportsNormalizationEnumUnsupported()
+    {
+        $this->assertFalse($this->normalizer->supportsNormalization(new \stdClass()));
+    }
+
+    /**
+     * @requires PHP >= 8.1
+     */
+    public function testNormalize()
+    {
+        $this->assertSame('D', $this->normalizer->normalize(EnumBackedDummy::Diamonds));
+    }
+
+    /**
+     * @requires PHP >= 8.1
+     */
+    public function testSupportsDenormalization()
+    {
+        $this->assertTrue($this->normalizer->supportsDenormalization('D', EnumBackedDummy::class));
+        $this->assertFalse($this->normalizer->supportsDenormalization('D', EnumPureDummy::class));
+        $this->assertFalse($this->normalizer->supportsDenormalization('D', \stdClass::class));
+    }
+
+    /**
+     * @requires PHP < 8.1
+     */
+    public function testSupportsDenormalizationEnumUnsupported()
+    {
+        $this->assertFalse($this->normalizer->supportsDenormalization('D', \stdClass::class));
+    }
+
+    /**
+     * @requires PHP >= 8.1
+     */
+    public function testDenormalize()
+    {
+        $this->assertEquals(EnumBackedDummy::Diamonds, $this->normalizer->denormalize('D', EnumBackedDummy::class));
+    }
+
+    /**
+     * @requires PHP >= 8.1
+     */
+    public function testDenormalizeThrowsException()
+    {
+        $this->expectException(NotNormalizableValueException::class);
+
+        $this->normalizer->denormalize('Z', EnumBackedDummy::class);
+    }
+}
diff --git a/src/Symfony/Component/Serializer/Tests/SerializerTest.php b/src/Symfony/Component/Serializer/Tests/SerializerTest.php
@@ -33,6 +33,7 @@
 use Symfony\Component\Serializer\Mapping\Loader\AnnotationLoader;
 use Symfony\Component\Serializer\Normalizer\AbstractObjectNormalizer;
 use Symfony\Component\Serializer\Normalizer\ArrayDenormalizer;
+use Symfony\Component\Serializer\Normalizer\BackedEnumNormalizer;
 use Symfony\Component\Serializer\Normalizer\CustomNormalizer;
 use Symfony\Component\Serializer\Normalizer\DenormalizerAwareInterface;
 use Symfony\Component\Serializer\Normalizer\DenormalizerInterface;
@@ -52,6 +53,8 @@
 use Symfony\Component\Serializer\Tests\Fixtures\DummyMessageNumberOne;
 use Symfony\Component\Serializer\Tests\Fixtures\DummyMessageNumberTwo;
 use Symfony\Component\Serializer\Tests\Fixtures\NormalizableTraversableDummy;
+use Symfony\Component\Serializer\Tests\Fixtures\Normalizer\EnumBackedClassDummy;
+use Symfony\Component\Serializer\Tests\Fixtures\Normalizer\EnumBackedDummy;
 use Symfony\Component\Serializer\Tests\Fixtures\TraversableDummy;
 use Symfony\Component\Serializer\Tests\Normalizer\TestDenormalizer;
 use Symfony\Component\Serializer\Tests\Normalizer\TestNormalizer;
@@ -645,6 +648,30 @@ public function testDeserializeAndUnwrap()
             $serializer->deserialize($jsonData, __NAMESPACE__.'\Model', 'json', [UnwrappingDenormalizer::UNWRAP_PATH => '[baz][inner]'])
         );
     }
+
+    /**
+     * @requires PHP >= 8.1
+     */
+    public function testSerializeBackedEnum()
+    {
+        $serializer = new Serializer([new BackedEnumNormalizer(), new ObjectNormalizer()], ['json' => new JsonEncoder()]);
+        $card = new EnumBackedClassDummy(EnumBackedDummy::Diamonds);
+        $serialized = $serializer->serialize($card, 'json');
+
+        $this->assertEquals('{"suit":"D"}', $serialized);
+    }
+
+    /**
+     * @requires PHP >= 8.1
+     */
+    public function testDeserializeBackedEnum()
+    {
+        $serialized = '{"suit": "D"}';
+        $serializer = new Serializer([new BackedEnumNormalizer(), new ObjectNormalizer()], ['json' => new JsonEncoder()]);
+        $card = $serializer->deserialize($serialized, EnumBackedClassDummy::class, 'json');
+
+        $this->assertEquals(EnumBackedDummy::Diamonds, $card->suit);
+    }
 }
 
 class Model