Unpack and beautify JavaScript

unpack.and.beautify.js

// blog post: http://blog.slashpoundbang.com/post/2428557007/unpack-and-beautify-javascript

// Assumes js_beautify is available: see https://github.com/einars/js-beautify/raw/master/beautify.js
function unpack_and_beautify(value) {
  var position = 0,
      open_string = "eval(function(",
      open_index = -1,
      close_string = "'.split('|'),0,{}))",
      close_index = -1,
      close_length = close_string.length,
      string = '',
      pack;

  while (true) {
    open_index = value.indexOf(open_string, open_index + 1);
    close_index = value.indexOf(close_string, close_index + 1);
    if (open_index == -1 || close_index == -1) {
      string += value.substring(position, value.length);
      break;
    }
    else {
      string += value.substring(position, open_index);
      pack = value.substring(open_index, close_index + close_length);
      try {
        eval("var tmp = String" + pack.substring(4));
        string += tmp;
      }
      catch (e) {
        window.console && console.log && console.log(e, pack);
        string += pack;
      }
      position = close_index + close_length;
    }
  };
  return js_beautify(string, {
    indent_size: 2,
    space_after_anon_function: true,
  });
}