bug #416 [Live] Support (de)hydrating nullable backed Enum's (kbond)

This PR was merged into the 2.x branch.

Discussion
----------

[Live] Support (de)hydrating nullable backed Enum's

| Q             | A
| ------------- | ---
| Bug fix?      | yes
| New feature?  | no
| Tickets       | Fix #414
| License       | MIT

Commits
-------

bfd7f8d [Live] support (de)hydrating Enum's

src/LiveComponent/src/LiveComponentHydrator.php

@@ -166,12 +166,15 @@ public function hydrate(object $component, array $data, string $componentName):
             }
 
             $value = $dehydratedValue;
+            $type = $property->getType() instanceof \ReflectionNamedType ? $property->getType() : null;
 
             if ($method = $liveProp->hydrateMethod()) {
                 // TODO: Error checking
                 $value = $component->$method($dehydratedValue);
-            } elseif ($property->getType() instanceof \ReflectionNamedType && !$property->getType()->isBuiltin()) {
-                $value = $this->normalizer->denormalize($value, $property->getType()->getName(), 'json', [self::LIVE_CONTEXT => true]);
+            } elseif (!$value && $type && $type->allowsNull() && is_a($type->getName(), \BackedEnum::class, true) && !\in_array($value, array_map(fn (\BackedEnum $e) => $e->value, $type->getName()::cases()))) {
+                $value = null;
+            } elseif (null !== $value && $type && !$type->isBuiltin()) {
+                $value = $this->normalizer->denormalize($value, $type->getName(), 'json', [self::LIVE_CONTEXT => true]);
             }
 
             foreach ($liveProp->exposed() as $exposedProperty) {

src/LiveComponent/tests/Fixtures/Component/WithEnums.php

@@ -0,0 +1,29 @@
+<?php
+
+namespace Symfony\UX\LiveComponent\Tests\Fixtures\Component;
+
+use Symfony\UX\LiveComponent\Attribute\AsLiveComponent;
+use Symfony\UX\LiveComponent\Attribute\LiveProp;
+use Symfony\UX\LiveComponent\DefaultActionTrait;
+use Symfony\UX\LiveComponent\Tests\Fixtures\Enum\EmptyStringEnum;
+use Symfony\UX\LiveComponent\Tests\Fixtures\Enum\IntEnum;
+use Symfony\UX\LiveComponent\Tests\Fixtures\Enum\StringEnum;
+use Symfony\UX\LiveComponent\Tests\Fixtures\Enum\ZeroIntEnum;
+
+#[AsLiveComponent('with_enum')]
+final class WithEnums
+{
+    use DefaultActionTrait;
+
+    #[LiveProp(writable: true)]
+    public ?IntEnum $int = null;
+
+    #[LiveProp(writable: true)]
+    public ?StringEnum $string = null;
+
+    #[LiveProp(writable: true)]
+    public ?ZeroIntEnum $zeroInt = null;
+
+    #[LiveProp(writable: true)]
+    public ?EmptyStringEnum $emptyString = null;
+}

src/LiveComponent/tests/Fixtures/Enum/EmptyStringEnum.php

@@ -0,0 +1,8 @@
+<?php
+
+namespace Symfony\UX\LiveComponent\Tests\Fixtures\Enum;
+
+enum EmptyStringEnum: string
+{
+    case EMPTY = '';
+}

src/LiveComponent/tests/Fixtures/Enum/IntEnum.php

@@ -0,0 +1,9 @@
+<?php
+
+namespace Symfony\UX\LiveComponent\Tests\Fixtures\Enum;
+
+enum IntEnum: int
+{
+    case HIGH = 10;
+    case LOW = 1;
+}

src/LiveComponent/tests/Fixtures/Enum/StringEnum.php

@@ -0,0 +1,9 @@
+<?php
+
+namespace Symfony\UX\LiveComponent\Tests\Fixtures\Enum;
+
+enum StringEnum: string
+{
+    case PENDING = 'pending';
+    case ACTIVE = 'active';
+}

src/LiveComponent/tests/Fixtures/Enum/ZeroIntEnum.php

@@ -0,0 +1,8 @@
+<?php
+
+namespace Symfony\UX\LiveComponent\Tests\Fixtures\Enum;
+
+enum ZeroIntEnum: int
+{
+    case ZERO = 0;
+}

src/LiveComponent/tests/Integration/LiveComponentHydratorTest.php

@@ -17,6 +17,10 @@
 use Symfony\UX\LiveComponent\Tests\Fixtures\Component\Component3;
 use Symfony\UX\LiveComponent\Tests\Fixtures\Component\ComponentWithArrayProp;
 use Symfony\UX\LiveComponent\Tests\Fixtures\Entity\Entity1;
+use Symfony\UX\LiveComponent\Tests\Fixtures\Enum\EmptyStringEnum;
+use Symfony\UX\LiveComponent\Tests\Fixtures\Enum\IntEnum;
+use Symfony\UX\LiveComponent\Tests\Fixtures\Enum\StringEnum;
+use Symfony\UX\LiveComponent\Tests\Fixtures\Enum\ZeroIntEnum;
 use Symfony\UX\LiveComponent\Tests\LiveComponentTestHelper;
 use Zenstruck\Foundry\Test\Factories;
 use Zenstruck\Foundry\Test\ResetDatabase;
@@ -279,4 +283,60 @@ public function testCanDehydrateAndHydrateComponentsWithEmptyAttributes(): void
 
         $this->assertSame([], $mounted->getAttributes()->all());
     }
+
+    /**
+     * @requires PHP >= 8.1
+     */
+    public function testCanHydrateEnums(): void
+    {
+        $mounted = $this->mountComponent('with_enum');
+
+        $dehydrated = $this->dehydrateComponent($mounted);
+
+        $this->assertNull($dehydrated['int']);
+        $this->assertNull($dehydrated['string']);
+
+        $mounted = $this->hydrateComponent($this->getComponent('with_enum'), $dehydrated, $mounted->getName());
+
+        $this->assertNull($mounted->getComponent()->int);
+        $this->assertNull($mounted->getComponent()->string);
+
+        $dehydrated['int'] = IntEnum::LOW->value;
+        $dehydrated['string'] = StringEnum::PENDING->value;
+
+        $mounted = $this->hydrateComponent($this->getComponent('with_enum'), $dehydrated, $mounted->getName());
+
+        $this->assertSame(IntEnum::LOW, $mounted->getComponent()->int);
+        $this->assertSame(StringEnum::PENDING, $mounted->getComponent()->string);
+
+        $dehydrated['int'] = null;
+        $dehydrated['string'] = null;
+
+        $mounted = $this->hydrateComponent($this->getComponent('with_enum'), $dehydrated, $mounted->getName());
+
+        $this->assertNull($mounted->getComponent()->int);
+        $this->assertNull($mounted->getComponent()->string);
+
+        $dehydrated['int'] = '';
+        $dehydrated['string'] = '';
+
+        $mounted = $this->hydrateComponent($this->getComponent('with_enum'), $dehydrated, $mounted->getName());
+
+        $this->assertNull($mounted->getComponent()->int);
+        $this->assertNull($mounted->getComponent()->string);
+
+        $dehydrated['zeroInt'] = 0;
+        $dehydrated['emptyString'] = '';
+
+        $mounted = $this->hydrateComponent($this->getComponent('with_enum'), $dehydrated, $mounted->getName());
+
+        $this->assertSame(ZeroIntEnum::ZERO, $mounted->getComponent()->zeroInt);
+        $this->assertSame(EmptyStringEnum::EMPTY, $mounted->getComponent()->emptyString);
+
+        $dehydrated['zeroInt'] = '0';
+
+        $mounted = $this->hydrateComponent($this->getComponent('with_enum'), $dehydrated, $mounted->getName());
+
+        $this->assertSame(ZeroIntEnum::ZERO, $mounted->getComponent()->zeroInt);
+    }
 }