Merge branch 'comment-error' into 'master'

Add error for ajax:error when submitting comments

Fixes #13814
![Screen_Shot_2016-02-25_at_1.54.56_PM](/uploads/d70d706d306079df1b00d70f09affb63/Screen_Shot_2016-02-25_at_1.54.56_PM.png)
cc @dblessing 

See merge request !2976

app/assets/javascripts/notes.js.coffee

@@ -30,6 +30,9 @@ class @Notes
     $(document).on "ajax:success", ".js-main-target-form", @addNote
     $(document).on "ajax:success", ".js-discussion-note-form", @addDiscussionNote
 
+    # catch note ajax errors
+    $(document).on "ajax:error", ".js-main-target-form", @addNoteError
+
     # change note in UI after update
     $(document).on "ajax:success", "form.edit-note", @updateNote
 
@@ -309,6 +312,10 @@ class @Notes
   addNote: (xhr, note, status) =>
     @renderNote(note)
 
+  addNoteError: (xhr, note, status) =>
+    flash = new Flash('Your comment could not be submitted! Please check your network connection and try again.', 'alert')
+    flash.pinTo('.md-area')
+
   ###
   Called in response to the new note form being submitted
 

features/steps/project/source/browse_files.rb

@@ -361,7 +361,7 @@ class Spinach::Features::ProjectSourceBrowseFiles < Spinach::FeatureSteps
   end
 
   step 'I can see the new rendered SVG image' do
-    expect(find('.file-content')).to have_css('img')
+    expect(page).to have_css('.file-content img')
   end
 
   private