From b60056f960c6f33b1341d41eb0eeea5ea7aff441 Mon Sep 17 00:00:00 2001
From: joshaber <joshaber@gmail.com>
Date: Thu, 3 Dec 2015 11:34:05 -0500
Subject: [PATCH] Added .getUpstreamBranch

---
 src/git-repository-async.js | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/src/git-repository-async.js b/src/git-repository-async.js
index c6d85943a..8bdb8ca22 100644
--- a/src/git-repository-async.js
+++ b/src/git-repository-async.js
@@ -251,9 +251,12 @@ export default class GitRepositoryAsync {
   // * `path` An optional {String} path in the repo to get this information for,
   //   only needed if the repository contains submodules.
   //
-  // Returns a {String} branch name such as `refs/remotes/origin/master`.
+  // Returns a {Promise} which resolves to a {String} branch name such as
+  // `refs/remotes/origin/master`.
   getUpstreamBranch (_path) {
-    throw new Error('Unimplemented')
+    return this._getRepo(_path)
+      .then(repo => repo.getCurrentBranch())
+      .then(branch => Git.Branch.upstream(branch))
   }
 
   // Public: Gets all the local and remote references.