Use persistent background pages (sindresorhus#221)

Author: notlmn

source/background.js

@@ -19,7 +19,8 @@ async function scheduleNextAlarm(interval) {
 	// Delay less than 1 minute will cause a warning
 	const delayInMinutes = Math.max(Math.ceil(intervalValue / 60), 1);
 
-	browser.alarms.create({delayInMinutes});
+	browser.alarms.clearAll();
+	browser.alarms.create('update', {delayInMinutes});
 }
 
 async function handleLastModified(newLastModified) {
@@ -47,15 +48,12 @@ async function updateNotificationCount() {
 
 function handleError(error) {
 	scheduleNextAlarm();
-
 	renderError(error);
 }
 
 function handleOfflineStatus() {
-	renderWarning('offline');
-
-	// Keep schedule for next alarm to keep background active
 	scheduleNextAlarm();
+	renderWarning('offline');
 }
 
 async function update() {
@@ -80,14 +78,6 @@ function handleInstalled(details) {
 	}
 }
 
-function handleConnectionStatus() {
-	if (navigator.onLine) {
-		update();
-	} else {
-		handleOfflineStatus();
-	}
-}
-
 async function onMessage(message) {
 	if (message === 'update') {
 		await addHandlers();
@@ -125,11 +115,11 @@ async function addHandlers() {
 }
 
 function init() {
-	window.addEventListener('online', handleConnectionStatus);
-	window.addEventListener('offline', handleConnectionStatus);
+	window.addEventListener('online', update);
+	window.addEventListener('offline', update);
 
 	browser.alarms.onAlarm.addListener(update);
-	browser.alarms.create({when: Date.now() + 2000});
+	scheduleNextAlarm();
 
 	browser.runtime.onMessage.addListener(onMessage);
 	browser.runtime.onInstalled.addListener(handleInstalled);

source/manifest.json

@@ -23,7 +23,7 @@
 		"notifications"
 	],
 	"background": {
-		"persistent": false,
+		"persistent": true,
 		"scripts": [
 			"browser-polyfill.min.js",
 			"background.js"