Merge pull request #70 from bshaffer/issue-68

Issue 68 - make CredentialsLoader abstract

src/CredentialsLoader.php

@@ -27,7 +27,7 @@
  * CredentialsLoader contains the behaviour used to locate and find default
  * credentials files on the file system.
  */
-class CredentialsLoader implements FetchAuthTokenInterface
+abstract class CredentialsLoader implements FetchAuthTokenInterface
 {
   const TOKEN_CREDENTIAL_URI = 'https://www.googleapis.com/oauth2/v3/token';
   const ENV_VAR = 'GOOGLE_APPLICATION_CREDENTIALS';
@@ -138,23 +138,6 @@ public static function makeCredentials($scope, Stream $jsonKeyStream)
     }
   }
 
- /**
-  * Implements FetchAuthTokenInterface#fetchAuthToken.
-  */
-  public function fetchAuthToken(ClientInterface $client = null)
-  {
-    return $this->auth->fetchAuthToken($client);
-  }
-
- /**
-  * Implements FetchAuthTokenInterface#getCacheKey.
-  */
-  public function getCacheKey()
-  {
-    return $this->auth->getCacheKey();
-  }
-
-
   /**
    * export a callback function which updates runtime metadata
    *

src/ServiceAccountCredentials.php

@@ -93,6 +93,14 @@ public function __construct($scope, $jsonKey,
     ]);
   }
 
+  /**
+   * Implements FetchAuthTokenInterface#fetchAuthToken.
+   */
+  public function fetchAuthToken(ClientInterface $client = null)
+  {
+    return $this->auth->fetchAuthToken($client);
+  }
+
  /**
   * Implements FetchAuthTokenInterface#getCacheKey.
   */

src/ServiceAccountJwtAccessCredentials.php

@@ -91,4 +91,12 @@ public function fetchAuthToken(ClientInterface $unusedClient = null)
     $access_token = $this->auth->toJwt();
     return array('access_token' => $access_token);
   }
+
+  /**
+   * Implements FetchAuthTokenInterface#getCacheKey.
+   */
+  public function getCacheKey()
+  {
+    return $this->auth->getCacheKey();
+  }
 }

src/UserRefreshCredentials.php

@@ -75,6 +75,14 @@ public function __construct($scope, $jsonKey,
     ]);
   }
 
+  /**
+   * Implements FetchAuthTokenInterface#fetchAuthToken.
+   */
+  public function fetchAuthToken(ClientInterface $client = null)
+  {
+    return $this->auth->fetchAuthToken($client);
+  }
+
  /**
   * Implements FetchAuthTokenInterface#getCacheKey.
   */