This post will probably give away my amateur status with the node stack but here goes...
I've been using the Karma test runner and
gulp watch task a lot while working on Aurelia and some personal projects. One thing I found annoying was there didn't seem to be anyway to stop these tasks and get back to the command prompt. Tonight I set my mind to it, "googled harder" and was happy to find that
CTRL + C does the trick.