Merge pull request #6445 from MatMoore/forum_vote_race_condition

Vote buttons should be disabled while in use

AUTHORS

@@ -195,3 +195,4 @@ Dino Cikatić <dcikatic@edx.org>
 Davorin Šego <dsego@edx.org>
 Marko Jevtić <mjevtic@edx.org>
 Ahsan Ulhaq <ahsan@edx.org>
+Mat Moore <mat@mooresoftware.co.uk>

common/static/coffee/spec/discussion/utils_spec.coffee

@@ -25,3 +25,24 @@ describe 'DiscussionUtil', ->
       # if the ajax call ends in failure, the model state should be reverted
       deferred.reject()
       expect(model.attributes).toEqual({hello: false, number: 42})
+
+    it "rolls back the changes if the associated element is disabled", ->
+      spyOn(DiscussionUtil, "safeAjax").andCallThrough()
+
+      model = new Backbone.Model({hello: false, number: 42})
+      updates = {hello: "world"}
+
+      # This is the element that is disabled/enabled while the ajax request is
+      # in progress
+      $elem = jasmine.createSpyObj('$elem', ['attr'])
+      $elem.attr.andReturn(true)
+
+      res = DiscussionUtil.updateWithUndo(model, updates, {foo: "bar", $elem:$elem}, "error message")
+
+      expect($elem.attr).toHaveBeenCalledWith("disabled")
+      expect(DiscussionUtil.safeAjax).toHaveBeenCalled()
+      expect(model.attributes).toEqual({hello: false, number: 42})
+
+      failed = false
+      res.fail(() => failed = true)
+      expect(failed).toBe(true);

common/static/coffee/src/discussion/utils.coffee

@@ -134,8 +134,12 @@ class @DiscussionUtil
 
   @safeAjax: (params) ->
     $elem = params.$elem
+
     if $elem and $elem.attr("disabled")
-      return
+      deferred = $.Deferred()
+      deferred.reject()
+      return deferred.promise()
+
     params["url"] = URI(params["url"]).addSearch ajax: 1
     params["beforeSend"] = ->
       if $elem

common/static/coffee/src/discussion/views/discussion_thread_view.coffee

@@ -127,7 +127,7 @@ if Backbone?
         $loading: elem
         takeFocus: true
         complete: =>
-          @responseRequest = null
+          @responsesRequest = null
         success: (data, textStatus, xhr) =>
           Content.loadContentInfos(data['annotated_content_info'])
           if @isQuestion()