Added state cloning if it is object

Memento/Memento.php

@@ -4,11 +4,11 @@ namespace DesignPatterns\Memento;
 
 class Memento
 {
-    /* @var string */
+    /* @var mixed */
     private $state;
 
     /**
-     * @param string $stateToSave
+     * @param mixed $stateToSave
      */
     public function __construct($stateToSave)
     {
@@ -16,7 +16,7 @@ class Memento
     }
 
     /**
-     * @return string
+     * @return mixed
      */
     public function getState()
     {

Memento/Originator.php

@@ -4,14 +4,14 @@ namespace DesignPatterns\Memento;
 
 class Originator
 {
-    /* @var string */
+    /* @var mixed */
     private $state;
 
     // The class could also contain additional data that is not part of the
     // state saved in the memento..
 
     /**
-     * @param string $state
+     * @param mixed $state
      */
     public function setState($state)
     {
@@ -23,7 +23,9 @@ class Originator
      */
     public function saveToMemento()
     {
-        return new Memento($this->state);
+        $state = is_object($this->state) ? clone $this->state : $this->state;
+
+        return new Memento($state);
     }
 
     public function restoreFromMemento(Memento $memento)

Tests/Memento/MementoTest.php

@@ -5,12 +5,12 @@ namespace DesignPatterns\Tests\Memento;
 use DesignPatterns\Memento;
 
 /**
- * MementoTest tests memento design pattern
+ * MementoTest tests the memento pattern
  */
 class MementoTest extends \PHPUnit_Framework_TestCase
 {
 
-    public function testOriginator()
+    public function testStringState()
     {
         $originator = new Memento\Originator();
         $originator->setState("State1");
@@ -33,4 +33,37 @@ class MementoTest extends \PHPUnit_Framework_TestCase
 
         $this->assertAttributeEquals("State2", "state", $originator);
     }
+
+    public function testObjectState()
+    {
+        $originator = new Memento\Originator();
+
+        $foo = new \stdClass();
+        $foo->data = "foo";
+
+        $originator->setState($foo);
+
+        $this->assertAttributeEquals($foo, "state", $originator);
+
+        $savedState = $originator->saveToMemento();
+
+        $this->assertAttributeEquals($foo, "state", $savedState);
+
+        $bar = new \stdClass();
+        $bar->data = "bar";
+
+        $originator->setState($bar);
+
+        $this->assertAttributeEquals($bar, "state", $originator);
+
+        $originator->restoreFromMemento($savedState);
+
+        $this->assertAttributeEquals($foo, "state", $originator);
+
+        $foo->data = null;
+
+        $this->assertAttributeNotEquals($foo, "state", $savedState);
+
+        $this->assertAttributeNotEquals($foo, "state", $originator);
+    }
 }