Support setting refreshToken

src/Token/AccessToken.php

@@ -22,7 +22,7 @@
  *
  * @link http://tools.ietf.org/html/rfc6749#section-1.4 Access Token (RFC 6749, §1.4)
  */
-class AccessToken implements AccessTokenInterface, ResourceOwnerAccessTokenInterface
+class AccessToken implements AccessTokenInterface, ResourceOwnerAccessTokenInterface, SettableRefreshTokenInterface
 {
     /**
      * @var string
@@ -169,6 +169,14 @@ public function getRefreshToken()
         return $this->refreshToken;
     }
 
+    /**
+     * @inheritdoc
+     */
+    public function setRefreshToken($refreshToken)
+    {
+        $this->refreshToken = $refreshToken;
+    }
+
     /**
      * @inheritdoc
      */

src/Token/SettableRefreshTokenInterface.php

@@ -0,0 +1,26 @@
+<?php
+/**
+ * This file is part of the league/oauth2-client library
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ *
+ * @copyright Copyright (c) Alex Bilbie <[email protected]>
+ * @license http://opensource.org/licenses/MIT MIT
+ * @link http://thephpleague.com/oauth2-client/ Documentation
+ * @link https://packagist.org/packages/league/oauth2-client Packagist
+ * @link https://github.com/thephpleague/oauth2-client GitHub
+ */
+
+namespace League\OAuth2\Client\Token;
+
+interface SettableRefreshTokenInterface
+{
+    /**
+     * Sets or replaces the refresh token with the provided refresh token.
+     *
+     * @param string $refreshToken
+     * @return void
+     */
+    public function setRefreshToken($refreshToken);
+}

test/src/Token/AccessTokenTest.php

@@ -123,6 +123,23 @@ public function testGetRefreshToken()
         self::tearDownForBackwardsCompatibility();
     }
 
+    public function testSetRefreshToken()
+    {
+        $refreshToken = 'refresh_token';
+
+        $options = [
+            'access_token' => 'access_token',
+        ];
+
+        $token = $this->getAccessToken($options);
+
+        $token->setRefreshToken($refreshToken);
+
+        $this->assertEquals($refreshToken, $token->getRefreshToken());
+
+        self::tearDownForBackwardsCompatibility();
+    }
+
     public function testHasNotExpiredWhenPropertySetInFuture()
     {
         $options = [