Global functions in CoffeeScript?

Question

Ruby on Rails

I am finally switching to CoffeeScript in my rails project. Before that, everything was written in pure JavaScript. A problem arose immediately.
File1

$ ->
    function1 -> some code

Previously I had:

$(function(){
  function1 = function(){some code}
});

File2

$ ->
  function1()

Previously it was:

$(function(){
  function1();
});

Everything works in pure Javascript. And then it wraps in an additional scope or how to call it correctly and gives an error function1 is not defined
How to get around this problem?