--- /dev/null
+<?php
+
+/*
+ * This file is part of Psy Shell.
+ *
+ * (c) 2012-2017 Justin Hileman
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Psy\CodeCleaner;
+
+use PhpParser\Node;
+use PhpParser\Node\Expr\ConstFetch;
+use PhpParser\Node\Expr\Instanceof_ as InstanceofStmt;
+use PhpParser\Node\Scalar;
+use PhpParser\Node\Scalar\Encapsed;
+use Psy\Exception\FatalErrorException;
+
+/**
+ * Validate that the instanceof statement does not receive a scalar value or a non-class constant.
+ *
+ * @author Martin HasoĊ <martin.hason@gmail.com>
+ */
+class InstanceOfPass extends CodeCleanerPass
+{
+ /**
+ * Validate that the instanceof statement does not receive a scalar value or a non-class constant.
+ *
+ * @throws FatalErrorException if a scalar or a non-class constant is given
+ *
+ * @param Node $node
+ */
+ public function enterNode(Node $node)
+ {
+ if (!$node instanceof InstanceofStmt) {
+ return;
+ }
+
+ if (($node->expr instanceof Scalar && !$node->expr instanceof Encapsed) || $node->expr instanceof ConstFetch) {
+ throw new FatalErrorException('instanceof expects an object instance, constant given');
+ }
+ }
+}