partial app.js for R.O.A.S.

matildem.js

if('serviceWorker' in navigator){
	navigator.serviceWorker
		.register('./service-worker.js')
		.then(function(){
            window.isUpdateAvailable = new Promise(function (resolve, reject) {
                if ('serviceWorker' in navigator && ['localhost', '127'].indexOf(location.hostname) === -1) {
                    navigator.serviceWorker.register('service-worker.js').then(function (reg) {
                        reg.onupdatefound = function () {
                            var installingWorker = reg.installing;
                            installingWorker.onstatechange = function () {
                                switch (installingWorker.state) {
                                    case 'installed':
                                        if (navigator.serviceWorker) {
                                            resolve(true);
                                            alert('There is an update available for this app, please reload.');
                                        } else {
                                            // no update available
                                            resolve(false);
                                        }
                                        break;
                                }
                            };
                        };
                    }).catch(function (err) {
                        return console.error('[SW ERROR]', err);
                    });
                }
            });
			console.log('loaded service worker');
		});
}