jsENUM.js

//enum is a reserved word in new ES6 reserved words list, that's the reason the method call ENUM_
class Enum_ {
  constructor(...list) {
    const objList = list.reduce((acummulator, value) => {
      acummulator[value] = Symbol(value);
      return acummulator;
    }, {});

    return Object.freeze(objList);
  }
}

//usage examples
const COLORS = new Enum_("RED", "GREEN", "BLUE");
const SIZE = new Enum_("SMALL", "MEDIUM", "LARGE", "HUGE");
const STATUS = new Enum_("SOLD", "AVAILABLE");