gistfile1.txt

Ember.autoComputed = function () {
  var args = Array.prototype.slice(arguments);
  
  if (!args.length) return;
  
  var func = args.pop();
  
  if (typeof func !== 'function') return;
  
  var depKeys = args.slice(0, -1);
  
  if (!depKeys.length) return Ember.computed(func);
  
  var str = func.toString();

  var funcDef = str.substr(0, str.indexOf('{'}));
  var openParIndex = funcDef.indexOf('(');
  var closeParIndex = funcDef.indexOf(')');
  var funcArgs = funcDef.substr(openParIndex + 1, closeParIndex - openParIndex - 1);
  var newArgs = funcArgs.length ? funcArgs.split(", ") : [];
  var funcBodyStartIdx = str.indexOf('{');
  var funcBodyEndIdx = str.lastIndexOf('}');
  var funcBody = str.substr(funcBodyStartIdx + 1, funcBodyEndIdx - funcBodyStartIdx - 1);

  var newFunc = [];
  
  for (var i = 0, depKey; i < depKeys.length; i++) {
    depKey = depKeys[i];
    newFunc.push("var " + depKey + " = this.get('" + depKey + "');"));
  }
  
  newFunc.push(funcBody);
  newFunc = newFunc.join("\n");
  newArgs.push(newFunc);
  
  var computedProps = depKeys.concat([Function.apply(null, newArgs)])
  
  return Ember.computed.apply(null, computedProps);
}