app.js

var _reg = null;

async function initSW() {
    return new Promise((resolve, reject) => {
        navigator.serviceWorker.register("sw9.js", { scope: '/' }).then(function (reg) {
            _reg = reg;
            if (_reg.active === null) {
                var installingWorker = _reg.installing;
                installingWorker.onstatechange = function (stateEvt) {
                    if (stateEvt.target.state === "activated") {
                        console.log('cold reload SW activated, resolving!!!');
                        resolve();
                    }
                };
            } else {
                console.log('warm reload SW active:' + _reg.active.scriptURL);
                _installingWarmWorker = _reg.installing;
                if (_installingWarmWorker) {
                    console.log('We are going to install SW:' + _installingWarmWorker.scriptURL);
                    _reg.onupdatefound = function (newreg) {

                        _reg = null;

                        newreg.currentTarget.installing.onstatechange = function (stateEvt) {
                            console.log('warm reload.onstatechange: svc wkr stateEvt.target.state:' + stateEvt.target.state);
                            if (stateEvt.target.state === 'activated') {
                                console.log('warm reload: svc wkr state is activated, resolving now!!!');
                                resolve();
                                _reg = newreg.currentTarget;
                            }
                        };
                    };
                } else {
                    console.log('Posting claim');
                    reg.active.postMessage('claim');
                    resolve();
                }
            }
        });
    });
}

let _resolveIdComplete = null;
let _winId = null;
async function getId() {
    return new Promise((resolve, reject) => {
        _resolveIdComplete = resolve;
        _reg.active.postMessage('resolveId');
    })
}
function handleResolve(Id) {
    console.log('SW is activated!!! proceed');
    _winId = Id;
}

async function init() {
    await initSW();
    await getId().then(handleResolve);
}

async function main() {
    await init();

    // This is the starting!!!
    console.log('Creating worker with winId:' + _winId);
    let w = new Worker('worker.js');
    //w.postMessage({eventType:'initWndId', wndId:_winId});
    w.postMessage(_winId);
}

main();

navigator.serviceWorker.addEventListener('message', function (e) {
    if (e.data.resolveIdDone = 1) {
        console.log('app.js received resolveIdDone!!!');
        _resolveIdComplete(e.data.winId);
    }
});