fix: datetime caster with datetime object (#514)

Author: brendt

src/Tempest/Mapper/src/Casters/DateTimeCaster.php

@@ -32,6 +32,10 @@ public static function fromProperty(PropertyReflector $property): DateTimeCaster
 
     public function cast(mixed $input): DateTimeInterface
     {
+        if ($input instanceof DateTimeInterface) {
+            return $input;
+        }
+
         if ($this->immutable) {
             $date = DateTimeImmutable::createFromFormat($this->format, $input);
         } else {

tests/Integration/Mapper/Fixtures/ObjectWithBuiltInCasters.php

@@ -10,6 +10,8 @@
 
 final class ObjectWithBuiltInCasters
 {
+    public DateTimeImmutable $dateTimeObject;
+
     public DateTimeImmutable $dateTimeImmutable;
 
     public DateTime $dateTime;

tests/Integration/Mapper/Mappers/ArrayToObjectMapperTestCase.php

@@ -4,6 +4,7 @@
 
 namespace Tests\Tempest\Integration\Mapper\Mappers;
 
+use DateTimeImmutable;
 use InvalidArgumentException;
 use Tempest\Http\Method;
 use function Tempest\map;
@@ -64,6 +65,7 @@ public function test_default_values(): void
     public function test_built_in_casters(): void
     {
         $object = map([
+            'dateTimeObject' => new DateTimeImmutable('2024-01-01 10:10:10'),
             'dateTimeImmutable' => '2024-01-01 10:10:10',
             'dateTime' => '2024-01-01 10:10:10',
             'dateTimeWithFormat' => '01/12/2024 10:10:10',
@@ -72,6 +74,7 @@ public function test_built_in_casters(): void
             'int' => '1',
         ])->to(ObjectWithBuiltInCasters::class);
 
+        $this->assertSame('2024-01-01 10:10:10', $object->dateTimeObject->format('Y-m-d H:i:s'));
         $this->assertSame('2024-01-01 10:10:10', $object->dateTimeImmutable->format('Y-m-d H:i:s'));
         $this->assertSame('2024-01-01 10:10:10', $object->dateTime->format('Y-m-d H:i:s'));
         $this->assertSame('2024-12-01 10:10:10', $object->dateTimeWithFormat->format('Y-m-d H:i:s'));