Extract dedicated ThisDependentNodeVisitor class

Replace inline NodeFinder usage with a dedicated NodeVisitor class
for detecting $this-dependent expressions in trait context.

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

Author: phpstan-bot

src/Rules/Comparison/ImpossibleCheckTypeHelper.php

@@ -8,9 +8,7 @@
 use PhpParser\Node\Expr\FuncCall;
 use PhpParser\Node\Expr\MethodCall;
 use PhpParser\Node\Expr\StaticCall;
-use PhpParser\Node\Expr\Variable;
-use PhpParser\Node\Name;
-use PhpParser\NodeFinder;
+use PhpParser\NodeTraverser;
 use PHPStan\Analyser\MutatingScope;
 use PHPStan\Analyser\Scope;
 use PHPStan\Analyser\TypeSpecifier;
@@ -424,22 +422,12 @@ private function isExpressionDependentOnTraitContext(Scope $scope, Expr $expr):
 
 	private static function isExpressionDependentOnThis(Expr $expr): bool
 	{
-		$nodeFinder = new NodeFinder();
-		return $nodeFinder->findFirst([$expr], static function (Node $node): bool {
-			if ($node instanceof Variable && $node->name === 'this') {
-				return true;
-			}
-
-			if (
-				($node instanceof Expr\StaticPropertyFetch || $node instanceof Expr\StaticCall)
-				&& $node->class instanceof Name
-				&& in_array($node->class->toString(), ['self', 'static', 'parent'], true)
-			) {
-				return true;
-			}
+		$visitor = new ThisDependentNodeVisitor();
+		$traverser = new NodeTraverser();
+		$traverser->addVisitor($visitor);
+		$traverser->traverse([$expr]);
 
-			return false;
-		}) !== null;
+		return $visitor->isFound();
 	}
 
 	private static function isSpecified(Scope $scope, Expr $node, Expr $expr): bool

src/Rules/Comparison/ThisDependentNodeVisitor.php

@@ -0,0 +1,50 @@
+<?php declare(strict_types = 1);
+
+namespace PHPStan\Rules\Comparison;
+
+use Override;
+use PhpParser\Node;
+use PhpParser\Node\Expr;
+use PhpParser\Node\Expr\Variable;
+use PhpParser\Node\Name;
+use PhpParser\NodeVisitorAbstract;
+use function in_array;
+
+final class ThisDependentNodeVisitor extends NodeVisitorAbstract
+{
+
+	private bool $found = false;
+
+	#[Override]
+	public function beforeTraverse(array $nodes): ?array
+	{
+		$this->found = false;
+		return null;
+	}
+
+	#[Override]
+	public function enterNode(Node $node): ?int
+	{
+		if ($node instanceof Variable && $node->name === 'this') {
+			$this->found = true;
+			return self::STOP_TRAVERSAL;
+		}
+
+		if (
+			($node instanceof Expr\StaticPropertyFetch || $node instanceof Expr\StaticCall)
+			&& $node->class instanceof Name
+			&& in_array($node->class->toString(), ['self', 'static', 'parent'], true)
+		) {
+			$this->found = true;
+			return self::STOP_TRAVERSAL;
+		}
+
+		return null;
+	}
+
+	public function isFound(): bool
+	{
+		return $this->found;
+	}
+
+}