feat(database): support union data transfer object casting

Author: innocenzi

packages/database/src/Casters/DataTransferObjectCaster.php

@@ -33,6 +33,16 @@ public static function accepts(PropertyReflector|TypeReflector $type): bool
             ? $type->getType()
             : $type;
 
+        if ($type->isUnion()) {
+            foreach ($type->split() as $memberType) {
+                if (static::accepts($memberType)) {
+                    return true;
+                }
+            }
+
+            return false;
+        }
+
         return $type->isClass() && $type->asClass()->getAttribute(SerializeAs::class) !== null;
     }
 

tests/Integration/Database/DtoSerialization/UnionDtoSerializationTest.php

@@ -0,0 +1,93 @@
+<?php
+
+namespace Tests\Tempest\Integration\Database\DtoSerialization;
+
+use PHPUnit\Framework\Attributes\Test;
+use Tempest\Database\MigratesUp;
+use Tempest\Database\Migrations\CreateMigrationsTable;
+use Tempest\Database\QueryStatement;
+use Tempest\Database\QueryStatements\CreateTableStatement;
+use Tempest\Mapper\MapperConfig;
+use Tempest\Mapper\SerializeAs;
+use Tests\Tempest\Integration\FrameworkIntegrationTestCase;
+
+use function Tempest\Database\query;
+
+final class UnionDtoSerializationTest extends FrameworkIntegrationTestCase
+{
+    #[Test]
+    public function can_serialize_union_object(): void
+    {
+        $config = $this->container->get(MapperConfig::class);
+        $config->serializeAs(TestUnionA::class, 'test_union_a');
+        $config->serializeAs(TestUnionB::class, 'test_union_b');
+        $config->serializeAs(TestNestedObject::class, 'test_object');
+
+        $this->database->migrate(CreateMigrationsTable::class, new class implements MigratesUp {
+            public string $name = '001_union_serialization';
+
+            public function up(): QueryStatement
+            {
+                return new CreateTableStatement('test_wrapper_models')
+                    ->primary()
+                    ->json('property');
+            }
+        });
+
+        query(TestWrapperModel::class)->create(property: new TestUnionA(
+            content: 'abc',
+            testObject: new TestNestedObject('def'),
+        ));
+
+        query(TestWrapperModel::class)->create(property: new TestUnionB(
+            message: '123',
+            testObject: new TestNestedObject('456'),
+        ));
+
+        $results = query(TestWrapperModel::class)->all();
+
+        $this->assertCount(2, $results);
+        $this->assertInstanceOf(TestUnionA::class, $results[0]->property);
+        $this->assertSame('abc', $results[0]->property->content);
+        $this->assertInstanceOf(TestNestedObject::class, $results[0]->property->testObject);
+        $this->assertSame('def', $results[0]->property->testObject->content);
+
+        $this->assertInstanceOf(TestUnionB::class, $results[1]->property);
+        $this->assertSame('123', $results[1]->property->message);
+        $this->assertInstanceOf(TestNestedObject::class, $results[1]->property->testObject);
+        $this->assertSame('456', $results[1]->property->testObject->content);
+    }
+}
+
+final class TestWrapperModel
+{
+    public function __construct(
+        public TestUnionA|TestUnionB $property,
+    ) {}
+}
+
+#[SerializeAs('test_object')]
+final class TestNestedObject
+{
+    public function __construct(
+        public string $content,
+    ) {}
+}
+
+#[SerializeAs('test_union_a')]
+final class TestUnionA
+{
+    public function __construct(
+        public string $content,
+        public TestNestedObject $testObject,
+    ) {}
+}
+
+#[SerializeAs('test_union_b')]
+final class TestUnionB
+{
+    public function __construct(
+        public string $message,
+        public TestNestedObject $testObject,
+    ) {}
+}