Add regression test for class-level isPure check with promoted properties

Verifies that @phpstan-all-methods-pure correctly propagates to methods
in classes with promoted constructor properties, even when the method's
$resolvedPhpDoc is null. This is a non-regression test for the isPure
condition moved outside the `if ($resolvedPhpDoc !== null)` block.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: phpstan-bot

tests/PHPStan/Rules/Pure/PureMethodRuleTest.php

@@ -279,6 +279,18 @@ public function testAllMethodsArePure(): void
 		]);
 	}
 
+	#[RequiresPhp('>= 8.0')]
+	public function testBug14138Pure(): void
+	{
+		$this->treatPhpDocTypesAsCertain = true;
+		$this->analyse([__DIR__ . '/data/bug-14138-pure.php'], [
+			[
+				'Impure echo in pure method Bug14138Pure\PureClassWithSideEffect::doSomething().',
+				31,
+			],
+		]);
+	}
+
 	public function testBug12382(): void
 	{
 		$this->treatPhpDocTypesAsCertain = true;

tests/PHPStan/Rules/Pure/data/bug-14138-pure.php

@@ -0,0 +1,34 @@
+<?php // lint >= 8.0
+
+namespace Bug14138Pure;
+
+/**
+ * @phpstan-all-methods-pure
+ */
+class PureClassWithPromotedProperties
+{
+	public function __construct(
+		protected int $value
+	) {}
+
+	public function getValue(): int
+	{
+		return $this->value;
+	}
+}
+
+/**
+ * @phpstan-all-methods-pure
+ */
+class PureClassWithSideEffect
+{
+	public function __construct(
+		protected int $value
+	) {}
+
+	public function doSomething(): int
+	{
+		echo 'side effect';
+		return $this->value;
+	}
+}