It's a breaking change but one I would personally love :)
Instead of referencing authService, you could provide the loginConfirmed and loginCancelled callbacks directly on the event arguments of the broadcast. That would remove a dependency. Example:
$rootScope.$on('event:auth-loginRequired', function (args) {
signin().then(
function() {
args.loginConfirmed();
},
function() {
args.loginCancelled();
});
});
Let me know if you'd like me to suggest a pull request!