Show commits ahead/behind upstream in status bar

src/app/git.coffee

@@ -27,9 +27,11 @@ class Git
     ignore: 1 << 14
 
   statuses: null
+  upstream: null
 
   constructor: (path, options={}) ->
     @statuses = {}
+    @upstream = {ahead: 0, behind: 0}
     @repo = GitRepository.open(path)
     refreshOnWindowFocus = options.refreshOnWindowFocus ? true
     if refreshOnWindowFocus

src/app/repository-status-handler.coffee

@@ -9,8 +9,10 @@ module.exports =
       statuses = {}
       for path, status of repo.getRepo().getStatuses()
         statuses[fs.join(workingDirectoryPath, path)] = status
+      upstream = repo.getAheadBehindCounts() ? {ahead: 0, behind: 0}
       repo.destroy()
     else
+      upstream = {}
       statuses = {}
 
-    callTaskMethod('statusesLoaded', statuses)
+    callTaskMethod('statusesLoaded', {statuses, upstream})

src/app/repository-status-task.coffee

@@ -9,8 +9,9 @@ class RepositoryStatusTask extends Task
   started: ->
     @callWorkerMethod('loadStatuses', @repo.getPath())
 
-  statusesLoaded: (statuses) ->
+  statusesLoaded: ({statuses, upstream}) ->
     @done()
-    unless _.isEqual(statuses, @repo.statuses)
-      @repo.statuses = statuses
-      @repo.trigger 'statuses-changed'
+    statusesUnchanged = _.isEqual(statuses, @repo.statuses) and _.isEqual(upstream, @repo.upstream)
+    @repo.statuses = statuses
+    @repo.upstream = upstream
+    @repo.trigger 'statuses-changed' unless statusesUnchanged

src/packages/status-bar/lib/status-bar-view.coffee

@@ -17,6 +17,8 @@ class StatusBarView extends View
       @span class: 'git-branch', outlet: 'branchArea', =>
         @span class: 'octicons branch-icon'
         @span class: 'branch-label', outlet: 'branchLabel'
+        @span class: 'octicons commits-ahead-label', outlet: 'commitsAhead'
+        @span class: 'octicons commits-behind-label', outlet: 'commitsBehind'
         @span class: 'git-status', outlet: 'gitStatusIcon'
       @span class: 'file-info', =>
         @span class: 'current-path', outlet: 'currentPath'
@@ -82,6 +84,16 @@ class StatusBarView extends View
     @gitStatusIcon.addClass('git-status octicons')
     return unless git?
 
+    if git.upstream.ahead > 0
+      @commitsAhead.text(git.upstream.ahead).show()
+    else
+      @commitsAhead.hide()
+
+    if git.upstream.behind > 0
+      @commitsBehind.text(git.upstream.behind).show()
+    else
+      @commitsBehind.hide()
+
     status = git.statuses[path]
     if git.isStatusModified(status)
       @gitStatusIcon.addClass('modified-status-icon')