Can't able to mock service call in ionic 3 application

hi

I am trying to mock service (http://localhost:8100/assets/data.json) call from https://github.com/kristofferandreasen/simple-ionic-3-app.
But i am able to run server.js. Still not able set up middle ware connection between application and server.js. Could you please suggest how to set up middle ware connection in this application
