Fix date tests for clamp

Author: kylekatarnls

tests/Php86/Php86Test.php

@@ -22,7 +22,15 @@ public function testClampSuccess(array $arguments, $result): void
     {
         [$value, $min, $max] = $arguments;
 
-        $this->assertSame($result, clamp($value, $min, $max));
+        $actual = clamp($value, $min, $max);
+
+        if ($value instanceof \DateTimeImmutable) {
+            $this->assertInstanceOf(\DateTimeImmutable::class, $actual);
+
+            $actual = $actual->format('Y-m-d');
+        }
+
+        $this->assertSame($result, $actual);
     }
 
     public function testClampNanReturn(): void
@@ -86,11 +94,11 @@ public static function provideValidClampInput(): array
                 '2025-08-20',
             ],
             [
-                [new \DateTimeImmutable('2025-08-01'), new \DateTimeImmutable('2025-08-15'), (new \DateTimeImmutable('2025-09-15'))->format('Y-m-d')],
+                [new \DateTimeImmutable('2025-08-01'), new \DateTimeImmutable('2025-08-15'), new \DateTimeImmutable('2025-09-15')],
                 '2025-08-15',
             ],
             [
-                [new \DateTimeImmutable('2025-08-20'), new \DateTimeImmutable('2025-08-15'), (new \DateTimeImmutable('2025-09-15'))->format('Y-m-d')],
+                [new \DateTimeImmutable('2025-08-20'), new \DateTimeImmutable('2025-08-15'), new \DateTimeImmutable('2025-09-15')],
                 '2025-08-20',
             ],
             [
@@ -145,11 +153,11 @@ public static function provideInvalidClampInput(): array
         return [
             [
                 [4, NAN, 6],
-                'clamp(): Argument #2 ($min) must be NAN',
+                'clamp(): Argument #2 ($min) must not be NAN',
             ],
             [
                 [7, 6, NAN],
-                'clamp(): Argument #3 ($max) must be NAN',
+                'clamp(): Argument #3 ($max) must not be NAN',
             ],
             [
                 [1, 3, 2],