Test NullsafeFirstClassCallableRule

Move the nullsafe first-class callable coverage out of MethodCallableRuleTest
into a dedicated NullsafeFirstClassCallableRuleTest.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Author: phpstan-bot

tests/PHPStan/Rules/Methods/MethodCallableRuleTest.php

@@ -59,17 +59,6 @@ public function testBug13596(): void
 		$this->analyse([__DIR__ . '/data/bug-13596.php'], []);
 	}
 
-	#[RequiresPhp('>= 8.1.0')]
-	public function testNullsafe(): void
-	{
-		$this->analyse([__DIR__ . '/data/method-callable-nullsafe.php'], [
-			[
-				'Cannot combine nullsafe operator with Closure creation.',
-				20,
-			],
-		]);
-	}
-
 	#[RequiresPhp('>= 8.1.0')]
 	public function testRule(): void
 	{

tests/PHPStan/Rules/Methods/NullsafeFirstClassCallableRuleTest.php

@@ -0,0 +1,31 @@
+<?php declare(strict_types = 1);
+
+namespace PHPStan\Rules\Methods;
+
+use PHPStan\Rules\Rule;
+use PHPStan\Testing\RuleTestCase;
+use PHPUnit\Framework\Attributes\RequiresPhp;
+
+/**
+ * @extends RuleTestCase<NullsafeFirstClassCallableRule>
+ */
+class NullsafeFirstClassCallableRuleTest extends RuleTestCase
+{
+
+	protected function getRule(): Rule
+	{
+		return new NullsafeFirstClassCallableRule();
+	}
+
+	#[RequiresPhp('>= 8.1.0')]
+	public function testRule(): void
+	{
+		$this->analyse([__DIR__ . '/data/nullsafe-first-class-callable.php'], [
+			[
+				'Cannot combine nullsafe operator with Closure creation.',
+				20,
+			],
+		]);
+	}
+
+}