Update main.ts

- Updated `main` to follow official quick start code from Electron.

Author: iamWing

src/main/main.ts

@@ -2,33 +2,26 @@
  * Entry point of the Election app.
  */
 import * as path from 'path';
-import * as url from 'url';
 import * as nodeEnv from '_utils/node-env';
 // eslint-disable-next-line import/no-extraneous-dependencies
 import { BrowserWindow, app, ipcMain } from 'electron';
 
 let mainWindow: Electron.BrowserWindow | undefined;
 
-function createWindow(): void {
+function createWindow() {
   // Create the browser window.
   mainWindow = new BrowserWindow({
     height: 600,
     width: 800,
     webPreferences: {
       devTools: nodeEnv.dev,
       preload: path.join(__dirname, './preload.bundle.js'),
-      webSecurity: false,
+      webSecurity: nodeEnv.prod,
     },
   });
 
   // and load the index.html of the app.
-  mainWindow.loadURL(
-    url.format({
-      pathname: path.join(__dirname, './index.html'),
-      protocol: 'file:',
-      slashes: true,
-    }),
-  ).finally(() => { /* no action */ });
+  mainWindow.loadFile('index.html').finally(() => { /* no action */ });
 
   // Emitted when the window is closed.
   mainWindow.on('closed', () => {
@@ -42,23 +35,19 @@ function createWindow(): void {
 // This method will be called when Electron has finished
 // initialization and is ready to create browser windows.
 // Some APIs can only be used after this event occurs.
-app.on('ready', createWindow);
+app.whenReady().then(() => {
+  createWindow();
 
-// Quit when all windows are closed.
-app.on('window-all-closed', () => {
-  // On OS X it is common for applications and their menu bar
-  // to stay active until the user quits explicitly with Cmd + Q
-  if (process.platform !== 'darwin') {
-    app.quit();
-  }
-});
+  app.on('activate', () => {
+    if (BrowserWindow.getAllWindows.length === 0) createWindow();
+  });
+}).finally(() => { /* no action */ });
 
-app.on('activate', () => {
-  // On OS X it"s common to re-create a window in the app when the
-  // dock icon is clicked and there are no other windows open.
-  if (mainWindow === undefined) {
-    createWindow();
-  }
+// Quit when all windows are closed, except on macOS. There, it's common
+// for applications and their menu bar to stay active until the user quits
+// explicitly with Cmd + Q.
+app.on('window-all-closed', () => {
+  if (process.platform !== 'darwin') app.quit();
 });
 
 ipcMain.on('renderer-ready', () => {