add fixture with date time diff

tests/Rules/NarrowPublicClassMethodParamTypeRule/Fixture/SkipDateTimeMix.php

@@ -0,0 +1,23 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Rector\TypePerfect\Tests\Rules\NarrowPublicClassMethodParamTypeRule\Fixture;
+
+final class SkipDateTimeMix
+{
+    public function markDate(
+        \DateTimeInterface $date
+    ): bool
+    {
+        return true;
+    }
+
+    static public function run(): void
+    {
+        $skipDateTimeMix = new SkipDateTimeMix();
+        $skipDateTimeMix->markDate(
+            new \DateTimeImmutable('15:30')
+        );
+    }
+}

tests/Rules/NarrowPublicClassMethodParamTypeRule/NarrowPublicClassMethodParamTypeRuleTest.php

@@ -26,6 +26,7 @@ public function testRule(array $filePaths, array $expectedErrorsWithLines): void
 
     public static function provideData(): Iterator
     {
+        yield [[__DIR__ . '/Fixture/SkipDateTimeMix.php'], []];
         yield [[__DIR__ . '/Fixture/SkipNonPublicClassMethod.php'], []];
 
         // skip first class callables as anything can be passed there