You already have the config and data file for YOLO in the test/cfg and test/data subfolders. You will have to download the pre-trained weight file here (258 MB). Or just run this:
cd node-yolo/test
wget http://pjreddie.com/media/files/yolo.weightsAll config and data files courtesy of https://github.com/pjreddie/darknet
Note: you will need ffmpeg to run the darknetTest.js
To test with your webcam:
node darknetTest.js
To test on an image:
node darknetImageTest.js