expected translation

var adapter;

adapter = {};

adapter.destroy = function() {
  var _i, _len, _ref, adapter;
  _ref = [1, 2, 3];
  for (_i = 0, _len = _ref.length; _i < _len; _i++) {
    adapter = _ref[_i];
    adapter = null;
  }
};

adapter.destroy();

console.log(adapter);

source

adapter={}
adapter.destroy = ()->
    for adapter in [1,2,3]
        adapter = null # this will destroy variable not in scope
    return
adapter.destroy()
console.log adapter

translation

var adapter;

adapter = {};

adapter.destroy = function() {
  var _i, _len, _ref;
  _ref = [1, 2, 3];
  for (_i = 0, _len = _ref.length; _i < _len; _i++) {
    adapter = _ref[_i];
    adapter = null;
  }
};

adapter.destroy();

console.log(adapter);