[MM-64867] Upgrade to Electron v37.2.2, some other package changes (#3462)

scripts/watch.js

@@ -1,13 +1,39 @@
 // Copyright (c) 2016-present Mattermost, Inc. All Rights Reserved.
 // See LICENSE.txt for license information.
 
-const electron = require('electron-connect').server.create({path: 'dist/'});
+const {spawn} = require('child_process');
+const path = require('path');
+
 const webpack = require('webpack');
 
 const mainConfig = require('../webpack.config.main.js');
 const preloadConfig = require('../webpack.config.preload.js');
 const rendererConfig = require('../webpack.config.renderer.js');
 
+let electronProcess = null;
+
+function startElectron() {
+    if (electronProcess) {
+        electronProcess.removeAllListeners();
+    }
+    electronProcess = spawn(
+        process.platform === 'win32' ? 'electron.cmd' : 'electron',
+        [path.resolve('dist/')],
+        {stdio: 'inherit'},
+    );
+}
+
+function restartElectron() {
+    if (electronProcess) {
+        electronProcess.kill();
+        electronProcess.on('close', () => {
+            startElectron();
+        });
+    } else {
+        startElectron();
+    }
+}
+
 Promise.all([mainConfig, preloadConfig, rendererConfig].map((config) => {
     return new Promise((resolve) => {
         const compiler = webpack(config);
@@ -18,9 +44,11 @@ Promise.all([mainConfig, preloadConfig, rendererConfig].map((config) => {
             process.stdout.write(stats.toString({colors: true}));
             process.stdout.write('\n');
             if (!stats.hasErrors()) {
-                electron.restart();
+                restartElectron();
             }
             resolve();
         });
     });
-})).then(() => electron.start());
+})).then(() => {
+    startElectron();
+});