state param for AbstractProvider::getAuthorizationUrl()

src/Provider/AbstractProvider.php

@@ -85,7 +85,7 @@ abstract class AbstractProvider implements ProviderInterface
 
     public function getAuthorizationUrl($options = array())
     {
-        $this->state = md5(uniqid(rand(), true));
+        $this->state = isset($options['state']) ? $options['state'] : md5(uniqid(rand(), true));
 
         $params = array(
             'client_id' => $this->clientId,

test/src/Provider/AbstractProviderTest.php

@@ -33,4 +33,12 @@ class AbstractProviderTest extends \PHPUnit_Framework_TestCase
         $grant = new \StdClass;
         $this->provider->getAccessToken($grant, array('invalid_parameter' => 'none'));
     }
+    
+    public function testAuthorizationUrlStateParam()
+    {
+        $this->assertContains('state=XXX', $this->provider->getAuthorizationUrl([
+            'state' => 'XXX'
+        ]));
+    }
+    
 }