Is Uglifier breaking my js?

Question

I'm using rails, uglifier and have just started using coffeescript. My coffee script for handling ajax completion is:

handleAjaxComplete = (xhr, response, status) ->
    myFeatherBox.close() if myFeatherBox?
    if $(xhr.target).hasClass "crud_create"
        #creation button hit
        myFeatherBox = $.featherlight response.responseText, afterOpen: ->
            $('form#frm_create').validate()
            $('#frm_create input[type!=hidden]').first().focus()
            return
    else #etc.

This becomes the following javascript:

handleAjaxComplete = function(xhr, response, status) {
  var new_aka_song_id;
  if (myFeatherBox != null) {
    myFeatherBox.close();
  }
  if ($(xhr.target).hasClass("crud_create")) {
    myFeatherBox = $.featherlight(response.responseText, {
      afterOpen: function() {
        $('form#frm_create').validate();
        $('#frm_create input[type!=hidden]').first().focus();
      }
    });
  } else //etc.

But then when I open the hosted page (it's on heroku), myFeatherBox.close() didn't seem to be running. I checked the uglified code and it seems to have become:

a=function(t,s) {
var o;
if(null!=h&&h.close(),$(t.target).hasClass("crud_create"))
    h=$.featherlight(s.responseText,{
        afterOpen:function(){
            $("form#frm_create").validate(),
            $("#frm_create input[type!=hidden]").first().focus()
        }
    });
else //etc.

(I've added some whitespace where I don't think it will matter to make it a little more readable).

My concern is with the condition on the third line of the uglified code. Am I correct that this is breaking what I'm trying to do? If so, how do I fix my coffee script so that the uglifier plays nice?

Answer 1

a, b 

in this context, is an expression whose value is the value of b (see the comma operator). That's why the uglified test

if(null!=h&&h.close(),$(t.target).hasClass("crud_create"))

is the same as

null!=h && h.close();
if ($(t.target).hasClass("crud_create"))

which is equivalent, due to the short-circuit behavior of &&, to

if (null!=h) h.close();
if ($(t.target).hasClass("crud_create"))

So there doesn't seem to be any problem in this uglyfication.