I am learning electronJS .
I have a main.dev.js whose content is :

import { app, BrowserWindow } from 'electron';

let mainWindow = null;

if (process.env.NODE_ENV === 'production') {
  const sourceMapSupport = require('source-map-support');
  sourceMapSupport.install();
}

if (
  process.env.NODE_ENV === 'development' ||
  process.env.DEBUG_PROD === 'true'
) {
  require('electron-debug')();
  const path = require('path');
  const p = path.join(__dirname, '..', 'app', 'node_modules');
  require('module').globalPaths.push(p);
}

const installExtensions = async () => {
  const installer = require('electron-devtools-installer');
  const forceDownload = !!process.env.UPGRADE_EXTENSIONS;
  const extensions = ['REACT_DEVELOPER_TOOLS', 'REDUX_DEVTOOLS'];

  return Promise.all(
    extensions.map(name => installer.default(installer[name], forceDownload))
  ).catch(console.log);
};

/**
 * Add event listeners...
 */

app.on('window-all-closed', () => {
  // Respect the OSX convention of having the application in memory even
  // after all windows have been closed
  if (process.platform !== 'darwin') {
    app.quit();
  }
});

app.on('ready', async () => {
  if (
    process.env.NODE_ENV === 'development' ||
    process.env.DEBUG_PROD === 'true'
  ) {
    await installExtensions();
  }

  mainWindow = new BrowserWindow({
    show: false,
    width: 1024,
    height: 728
  });

  mainWindow.loadURL(`file://${__dirname}/app.html`);

  // @TODO: Use 'ready-to-show' event
  // https://github.com/electron/electron/blob/master/docs/api/browser-window.md#using-ready-to-show-event
  mainWindow.webContents.on('did-finish-load', () => {
    if (!mainWindow) {
      throw new Error('"mainWindow" is not defined');
    }
    if (process.env.START_MINIMIZED) {
      mainWindow.minimize();
    } else {
      mainWindow.show();
      mainWindow.focus();
    }
  });

  mainWindow.on('closed', () => {
    mainWindow = null;
  });
});

Whose output is :

But nothing is happening on click Toggle Developer Tools option.
I am NOT able to find the issue ?

Note :

I want to debug an electron app whose git repo is : git repo
You can also clone the repo if needed ...
I am NOT able to post my question because of this error (please ignore) :
It looks like your post is mostly code; please add some more details.
It looks like your post is mostly code; please add some more details.
It looks like your post is mostly code; please add some more details.