.js and .map files in /src/?

Does anybody know why .js and .map files are showing up in my /src/ tree? I keep deleting them, but they keep coming back. (ionic 2 RC 1)

I’m seeing this suddenly now in the latest ionic version 2.0.1. For the past few weeks or so I haven’t seen these then the other day they showed up.

It makes my file tree look cluttered, does anyone know how to remove/exclude these from showing up. Screenshot attached