Which is the simplest way to add ES6 to a Rails 5.1 app?

Hi! As of Rails 5.1.4, which is the most simple way to use ES6 in a Rails application?

If you write your Javascript using webpacker, it will use ES6 out of the box.

For the asset pipeline, there's a sprockets-es6 gem.

I've heard about ES6 recently but I'm a little confused.

What is ES6 and what is the benefit of using it in Rails?

It's the next "version" of JS. Thus no specific upside of using it "in Rails". http://es6-features.org