4 files changed, 69 insertions, 1 deletions
diff --git a/platform/javascript/js/engine/config.js b/platform/javascript/js/engine/config.js
index ba61b14eb7..2e5e1ed0d1 100644
--- a/platform/javascript/js/engine/config.js
+++ b/platform/javascript/js/engine/config.js
@@ -107,6 +107,13 @@ const InternalConfig = function (initConfig) { // eslint-disable-line no-unused-
 		 */
 		experimentalVK: false,
 		/**
+		 * The progressive web app service worker to install.
+		 * @memberof EngineConfig
+		 * @default
+		 * @type {string}
+		 */
+		serviceWorker: '',
+		/**
 		 * @ignore
 		 * @type {Array.<string>}
 		 */
@@ -225,6 +232,8 @@ const InternalConfig = function (initConfig) { // eslint-disable-line no-unused-
 	 */
 	Config.prototype.update = function (opts) {
 		const config = opts || {};
+		// NOTE: We must explicitly pass the default, accessing it via
+		// the key will fail due to closure compiler renames.
 		function parse(key, def) {
 			if (typeof (config[key]) === 'undefined') {
 				return def;
@@ -247,6 +256,7 @@ const InternalConfig = function (initConfig) { // eslint-disable-line no-unused-
 		this.persistentDrops = parse('persistentDrops', this.persistentDrops);
 		this.experimentalVK = parse('experimentalVK', this.experimentalVK);
 		this.focusCanvas = parse('focusCanvas', this.focusCanvas);
+		this.serviceWorker = parse('serviceWorker', this.serviceWorker);
 		this.gdnativeLibs = parse('gdnativeLibs', this.gdnativeLibs);
 		this.fileSizes = parse('fileSizes', this.fileSizes);
 		this.args = parse('args', this.args);
diff --git a/platform/javascript/js/engine/engine.js b/platform/javascript/js/engine/engine.js
index 17a8df9e29..d2ba595083 100644
--- a/platform/javascript/js/engine/engine.js
+++ b/platform/javascript/js/engine/engine.js
@@ -189,6 +189,9 @@ const Engine = (function () {
 							preloader.preloadedFiles.length = 0; // Clear memory
 							me.rtenv['callMain'](me.config.args);
 							initPromise = null;
+							if (me.config.serviceWorker && 'serviceWorker' in navigator) {
+								navigator.serviceWorker.register(me.config.serviceWorker);
+							}
 							resolve();
 						});
 					});
diff --git a/platform/javascript/js/libs/library_godot_input.js b/platform/javascript/js/libs/library_godot_input.js
index 7a4d0d8126..1e64c260f8 100644
--- a/platform/javascript/js/libs/library_godot_input.js
+++ b/platform/javascript/js/libs/library_godot_input.js
@@ -87,7 +87,7 @@ const GodotInputGamepads = {
 		},
 
 		init: function (onchange) {
-			GodotEventListeners.samples = [];
+			GodotInputGamepads.samples = [];
 			function add(pad) {
 				const guid = GodotInputGamepads.get_guid(pad);
 				const c_id = GodotRuntime.allocString(pad.id);
diff --git a/platform/javascript/js/libs/library_godot_os.js b/platform/javascript/js/libs/library_godot_os.js
index 662d215443..12d06a8d51 100644
--- a/platform/javascript/js/libs/library_godot_os.js
+++ b/platform/javascript/js/libs/library_godot_os.js
@@ -368,3 +368,58 @@ const GodotEventListeners = {
 	},
 };
 mergeInto(LibraryManager.library, GodotEventListeners);
+
+const GodotPWA = {
+
+	$GodotPWA__deps: ['$GodotRuntime', '$GodotEventListeners'],
+	$GodotPWA: {
+		hasUpdate: false,
+
+		updateState: function (cb, reg) {
+			if (!reg) {
+				return;
+			}
+			if (!reg.active) {
+				return;
+			}
+			if (reg.waiting) {
+				GodotPWA.hasUpdate = true;
+				cb();
+			}
+			GodotEventListeners.add(reg, 'updatefound', function () {
+				const installing = reg.installing;
+				GodotEventListeners.add(installing, 'statechange', function () {
+					if (installing.state === 'installed') {
+						GodotPWA.hasUpdate = true;
+						cb();
+					}
+				});
+			});
+		},
+	},
+
+	godot_js_pwa_cb__sig: 'vi',
+	godot_js_pwa_cb: function (p_update_cb) {
+		if ('serviceWorker' in navigator) {
+			const cb = GodotRuntime.get_func(p_update_cb);
+			navigator.serviceWorker.getRegistration().then(GodotPWA.updateState.bind(null, cb));
+		}
+	},
+
+	godot_js_pwa_update__sig: 'i',
+	godot_js_pwa_update: function () {
+		if ('serviceWorker' in navigator && GodotPWA.hasUpdate) {
+			navigator.serviceWorker.getRegistration().then(function (reg) {
+				if (!reg || !reg.waiting) {
+					return;
+				}
+				reg.waiting.postMessage('update');
+			});
+			return 0;
+		}
+		return 1;
+	},
+};
+
+autoAddDeps(GodotPWA, '$GodotPWA');
+mergeInto(LibraryManager.library, GodotPWA);