Ionic 3: What are the steps I need to follow to setup unit, component, page, service testing existing?

My project is 50% done. I am unable to setup testing in Ionic 3.

It is not possible to clone ionic-team/ionic-unit-testing-example and start over. This article by joshmorony is for ionic 2 and steps in it are outdated.

Please provide some good references to ionic 3 testing.