Re-reading this article http://ify.io/lazy-loading-in-angularjs/ suggested to keep a $contentProvider
instance inside Angular App.
I came up with this code in my app.js
demoApp.config(function ($controllerProvider) {
demoApp.controller = $controllerProvider.register;
});
It enables me to write my controller as expected in a external javascript file :
angular.module("demoApp").controller('MouseTestCtrlA', fn);
Hope this can help !