How to run node.js ES6 file on mac

Can someone help me run a node.js file that has ES6 features? This is my current workflow:

• Save change in file
• npm run build --- builds file to my src/dist folder
• cd into my dist directory
• node
• var file = require('./index.js')
• file.someMethod()

Then when I make a change to my method, I need to repeat all the steps above again.

Does anyone know of a more efficient way to do this?

Thanks in advance!

via John Grayson