how to combine multiple instances of navigator.serviceWorker.register('sw.js') - service-worker

Question

for example in my index.html I have a code to detect an update for service worker and the code is like this:
if ('serviceWorker' in navigator) {
navigator.serviceWorker.register('sw.js').then(reg => {
reg.addEventListener('updatefound', () => {
// A wild service worker has appeared in reg.installing!
newWorker = reg.installing;
newWorker.addEventListener('statechange', () => {
// Has network.state changed?
switch (newWorker.state) {
case 'installed':
if (navigator.serviceWorker.controller) {
// new update available
showUpdateBar();
}
// No update available
break;
}
});
});
});
let refreshing;
navigator.serviceWorker.addEventListener('controllerchange', function () {
if (refreshing) return;
window.location.reload();
refreshing = true;
});
}
then in pushManager.js the code is like:
navigator.serviceWorker.register('sw.js')
.then(function (registration) {
messaging.useServiceWorker(registration);
// Request for permission
messaging.requestPermission()
.then(function() {
console.log('Notification permission granted.');
// TODO(developer): Retrieve an Instance ID token for use with FCM.
messaging.getToken()
.then(function(currentToken) {
if (currentToken) {
console.log('Token: ' + currentToken)
sendTokenToServer(currentToken);
// updateSubscriptionOnServer(currentToken);
} else {
console.log('No Instance ID token available. Request permission to generate one.');
setTokenSentToServer(false);
}
})
......
The pushManagr.js is included in both login/index.html and index.html.
I think that calling navigator.serviceWorker.register at multiple places will have adverse effect.
so how I can combine the two instances into one.

Answer 1

If possible, remove the registration of the serviceworker from pushManager.
If you want the registration instance of the serviceworker,use the api getRegistration()
navigator.serviceWorker.getRegistration(/*scope*/).then(function(registration) {
if(registration){
// Move all your firebase messaging code to here
messaging.useServiceWorker(registration);
}
});