Setup workbox to generate service worker

package.json

@@ -91,6 +91,8 @@
 		"dev": "electron .",
 		"dist": "electron-builder",
 		"beta": "electron-builder --windows portable",
+		"pwa": "node ./scripts/generate_pwa.js",
+		"prepublish": "npm run bundle && npm run pwa",
 		"webapp": "git checkout gh-pages && git merge master && git push && git checkout master"
 	},
 	"devDependencies": {
@@ -99,7 +101,8 @@
 		"electron-builder": "^22.9.1",
 		"electron-notarize": "^1.0.0",
 		"webpack": "^5.21.2",
-		"webpack-cli": "^4.5.0"
+		"webpack-cli": "^4.5.0",
+		"workbox-build": "^6.1.0"
 	},
 	"dependencies": {
 		"electron-updater": "^4.3.1"

scripts/generate_pwa.js

@@ -0,0 +1,22 @@
+const workbox = require('workbox-build');
+
+workbox.generateSW({
+	cacheId: 'blockbench',
+	globDirectory: './',
+	globPatterns: [
+		'./index.html',
+		'./favicon.png',
+		'./service_worker.js',
+
+		'./js/**/*',
+		'./lib/**/*',
+		'./css/**/*',
+		'./assets/**/*',
+		'./font/*',
+		'./lang/*',
+	],
+	swDest: './service_worker.js',
+	sourcemap: false
+}).then(({count, size}) => {
+	console.log(`Generated service-worker, which will precache ${count} files, totaling ${(size/1e6).toFixed(2)} MB.`);
+});