You can at least try decorators with babel using[1]

  $ babel --optional es7.decorators

or

  babel.transform("code", { optional: ["es7.decorators"] });

Here[2] is an article that describes how to use it for mixins

[1] https://babeljs.io/docs/usage/experimental

[2] http://raganwald.com/2015/06/26/decorators-in-es7.html