Better way to integrate JS-centric tests in a Rails application

We have a Rails-app defining several React components. These component are easily integrated in the Rails views through react-rails... So far so good.

But questions & doubts are raising while we start talking about testing flow: How to efficiently & elegantly test these components [in/a]side the Ruby-based tests flow? (I mean JS-testing pure JS code)

I would be pleased to use some tools like Mocha, Enzyme & so on...

Any advice, feedback or best-pratices on this topic?