Recent Node.js versions support modern JavaScript syntax. Let's use some of these shiny new JavaScript features to improve the tests we wrote in the preceding section.
EcmaScript 6
We'll be using EcmaScript 6 (EcmaScript 2015) features here. To learn more about EcmaScript 6 (EcmaScript 2015) see http://es6-features.org.
For this to work, we'll need at least Node version 5 installed, and preferably Node version 6 or greater.
Managing Node Versions
Check out nvm (https://github.com/creationix/nvm) or n (https://github.com/tj/n) for an easy way to switch between Node versions.
Node 6 and above should support all the syntax we'll be using; Node v5 will support all of it as long as we pass a special flag.
Transpilation For versions ...
