How to run another node.js script and then kill it

I want my testing script to be able to run my server and then kill it at the end of testing. In fact I will probably want to do this mulitple times in the testing script. I tired exec with shelljs. But that seems to me from running any commands after I start my server for testing it also seems like it would be hard to find the sever to kill it after starting it (especially on different OSes). How might I do such a thing?