handle DateTimeInterface objects

Author: michalsn

system/Entity/Entity.php

@@ -31,6 +31,7 @@
 use CodeIgniter\Entity\Exceptions\CastException;
 use CodeIgniter\I18n\Time;
 use DateTime;
+use DateTimeInterface;
 use Exception;
 use JsonSerializable;
 use ReturnTypeWillChange;
@@ -374,6 +375,11 @@ private function normalizeValue(mixed $data): mixed
                     '__class' => $data::class,
                     '__enum'  => $data instanceof BackedEnum ? $data->value : $data->name,
                 ];
+            } elseif ($data instanceof DateTimeInterface) {
+                return [
+                    '__class'    => $data::class,
+                    '__datetime' => $data->format(DATE_ATOM),
+                ];
             } else {
                 $objectData = get_object_vars($data);
             }

tests/system/Entity/EntityTest.php

@@ -21,6 +21,7 @@
 use CodeIgniter\Test\ReflectionHelper;
 use DateTime;
 use DateTimeInterface;
+use DateTimeZone;
 use JsonSerializable;
 use PHPUnit\Framework\Attributes\DataProvider;
 use PHPUnit\Framework\Attributes\Group;
@@ -2169,4 +2170,32 @@ public function testSyncOriginalWithEnumValues(): void
         $this->assertSame(ColorEnum::class, $colorData['__class']);
         $this->assertSame('GREEN', $colorData['__enum']);
     }
+
+    public function testHasChangedWithDateTimeInterface(): void
+    {
+        $entity = new class () extends Entity {
+            protected $attributes = [
+                'created_at' => null,
+            ];
+        };
+
+        // Test with Time object
+        $entity->created_at = Time::parse('2024-01-01 12:00:00', 'UTC');
+        $entity->syncOriginal();
+
+        $this->assertFalse($entity->hasChanged('created_at'));
+
+        $entity->created_at = Time::parse('2024-12-31 23:59:59', 'UTC');
+        $this->assertTrue($entity->hasChanged('created_at'));
+
+        $entity->syncOriginal();
+        $entity->created_at = Time::parse('2024-12-31 23:59:59', 'UTC');
+        $this->assertFalse($entity->hasChanged('created_at'));
+
+        // Test timezone difference detection
+        $entity->created_at = new DateTime('2024-01-01 12:00:00', new DateTimeZone('UTC'));
+        $entity->syncOriginal();
+        $entity->created_at = new DateTime('2024-01-01 12:00:00', new DateTimeZone('America/New_York'));
+        $this->assertTrue($entity->hasChanged('created_at'));
+    }
 }