phpjs/experimental/language/__FUNCTION__.js

php.js offers community built php functions in javascript

function __FUNCTION__() {
  // http://kevin.vanzonneveld.net
  // +   original by: Brett Zamir (http://brett-zamir.me)
  // %        note 1: Not a function in PHP, so in experimental
  // %        note 2: This function depends on the non-standard caller property of Function instances
  // *     example 1: function myFunc () {return __FUNCTION__();}
  // *     example 1: myFunc();
  // *     returns 1: 'myFunc'

  var getFuncName = function(fn) {
    var name = (/\W*function\s+([\w\$]+)\s*\(/).exec(fn);
    if (!name) {
      return '(Anonymous)';
    }
    return name[1];
  };
  return arguments.callee.caller && getFuncName(arguments.callee.caller);
}