Update test to match style

Author: oddevan

tests/Records/DateTimeInterfaceExample.php

@@ -0,0 +1,13 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Crell\Serde\Records;
+
+use DateTimeInterface;
+
+class DateTimeInterfaceExample {
+    public function __construct(
+        public DateTimeInterface $interfaceProperty,
+    ) {}
+}

tests/SerdeTestCases.php

@@ -26,6 +26,7 @@
 use Crell\Serde\Records\ClassWithReducibleProperty;
 use Crell\Serde\Records\CompoundTypes;
 use Crell\Serde\Records\DateTimeExample;
+use Crell\Serde\Records\DateTimeInterfaceExample;
 use Crell\Serde\Records\DictionaryKeyTypes;
 use Crell\Serde\Records\Drupal\EmailItem;
 use Crell\Serde\Records\Drupal\FieldItemList;
@@ -339,6 +340,11 @@ public static function round_trip_examples(): iterable
                 arrayMap: ['a' => [1, 2, 3]],
             ),
         ];
+        yield 'datetimeinterface_type' => [
+            'data' => new DateTimeInterfaceExample(
+                interfaceProperty: new \DateTimeImmutable('2025-12-25 12:34:56.789'),
+            ),
+        ];
     }
 
     public static function value_object_flatten_examples(): \Generator
@@ -1059,27 +1065,6 @@ public function datetime_fields_support_custom_output_format(): void
         self::assertEquals($expected, $result);
     }
 
-    #[Test]
-    public function datetime_field_can_be_datetimeinterface(): void
-    {
-        $s = new SerdeCommon(formatters: $this->formatters);
-
-        $timeString = '2025-12-25 12:34:56.789';
-        $stampImmutable = new \DateTimeImmutable($timeString);
-
-        $data = new class($stampImmutable) {
-            public function __construct(public readonly \DateTimeInterface $stamp) {}
-        };
-
-        $serialized = $s->serialize($data, $this->format);
-
-        $this->validateSerialized($serialized, __FUNCTION__);
-
-        $result = $s->deserialize($serialized, from: $this->format, to: get_class($data));
-
-        self::assertEquals($data, $result);
-    }
-
     #[Test]
     public function unixtime_fields_in_range_are_supported(): void
     {