Move script inside of MergeRequestTabs class

app/assets/javascripts/application.js.coffee

@@ -225,16 +225,6 @@ $ ->
         if $gutterIcon.hasClass('fa-angle-double-right')
           $gutterIcon.closest('a').trigger('click')
 
-  $(document)
-    .off 'shown.bs.tab', '.merge-request-tabs a[data-toggle="tab"]'
-    .on 'shown.bs.tab', '.merge-request-tabs a[data-toggle="tab"]', (e) ->
-      action = $(e.target).attr("data-action")
-      if action is 'diffs' 
-        $gutterIcon = $('.gutter-toggle').find('i')
-        if $gutterIcon.hasClass('fa-angle-double-right')
-          $gutterIcon.closest('a').trigger('click')
-
-
   $(document)
     .off 'click', 'aside .gutter-toggle'
     .on 'click', 'aside .gutter-toggle', (e) ->

app/assets/javascripts/merge_request_tabs.js.coffee

@@ -70,6 +70,7 @@ class @MergeRequestTabs
       @loadCommits($target.attr('href'))
     else if action == 'diffs'
       @loadDiff($target.attr('href'))
+      @shrinkView()
     else if action == 'builds'
       @loadBuilds($target.attr('href'))
 
@@ -185,3 +186,10 @@ class @MergeRequestTabs
 
   expandViewContainer: ->
     $('.container-fluid').removeClass('container-limited')
+
+  shrinkView: ->
+    $gutterIcon = $('.gutter-toggle i')
+
+    # Only when sidebar is collapsed
+    if $gutterIcon.is('.fa-angle-double-right')
+      $gutterIcon.closest('a').trigger('click')