How to force refresh the cached source files upon Ionic build/run?

What I did to solve my problem was to do re-initialize the Android platform.

ionic cordova platform remove android then ionic cordova platform add android

goto task manager and kill java se process

You need to increment your app version on your config.xml (at the top of your project folder) to reflect your changes before running:

<widget id="com.yourapp.id" version="0.0.8" xmlns="http://www.w3.org/ns/widgets" xmlns:cdv="http://cordova.apache.org/ns/1.0"

On this example, increment the attribute version to 0.0.9: version="0.0.9".

Then run android or run ios.