At StackShare[0] we're using the webpack-rails gem to use React and ES6 javascript.

https://github.com/mipearson/webpack-rails

It would be awesome if someone could write a migration guide for this switch. I'm sure a lot of Rails teams are using the webpack-rails gem and are planning to switch to the official gem.

[0] - https://stackshare.io/stackshare/stackshare