--- /dev/null
+<?php
+
+/*
+ * This file is part of the Prophecy.
+ * (c) Konstantin Kudryashov <ever.zet@gmail.com>
+ * Marcello Duarte <marcello.duarte@gmail.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Prophecy\Doubler\ClassPatch;
+
+use Prophecy\Doubler\Generator\Node\ClassNode;
+use Prophecy\Doubler\Generator\Node\MethodNode;
+
+/**
+ * Traversable interface patch.
+ * Forces classes that implement interfaces, that extend Traversable to also implement Iterator.
+ *
+ * @author Konstantin Kudryashov <ever.zet@gmail.com>
+ */
+class TraversablePatch implements ClassPatchInterface
+{
+ /**
+ * Supports nodetree, that implement Traversable, but not Iterator or IteratorAggregate.
+ *
+ * @param ClassNode $node
+ *
+ * @return bool
+ */
+ public function supports(ClassNode $node)
+ {
+ if (in_array('Iterator', $node->getInterfaces())) {
+ return false;
+ }
+ if (in_array('IteratorAggregate', $node->getInterfaces())) {
+ return false;
+ }
+
+ foreach ($node->getInterfaces() as $interface) {
+ if ('Traversable' !== $interface && !is_subclass_of($interface, 'Traversable')) {
+ continue;
+ }
+ if ('Iterator' === $interface || is_subclass_of($interface, 'Iterator')) {
+ continue;
+ }
+ if ('IteratorAggregate' === $interface || is_subclass_of($interface, 'IteratorAggregate')) {
+ continue;
+ }
+
+ return true;
+ }
+
+ return false;
+ }
+
+ /**
+ * Forces class to implement Iterator interface.
+ *
+ * @param ClassNode $node
+ */
+ public function apply(ClassNode $node)
+ {
+ $node->addInterface('Iterator');
+
+ $node->addMethod(new MethodNode('current'));
+ $node->addMethod(new MethodNode('key'));
+ $node->addMethod(new MethodNode('next'));
+ $node->addMethod(new MethodNode('rewind'));
+ $node->addMethod(new MethodNode('valid'));
+ }
+
+ /**
+ * Returns patch priority, which determines when patch will be applied.
+ *
+ * @return int Priority number (higher - earlier)
+ */
+ public function getPriority()
+ {
+ return 100;
+ }
+}