react/packages/react-devtools/app.js

// @flow

const { app, BrowserWindow } = require('electron'); // Module to create native browser window.
const { join } = require('path');

const argv = require('minimist')(process.argv.slice(2));
const projectRoots = argv._;

let mainWindow = null;

app.on('window-all-closed', function() {
  app.quit();
});

app.on('ready', function() {
  // Create the browser window.
  mainWindow = new BrowserWindow({
    width: 800,
    height: 600,
    icon: join(__dirname, 'icons/icon128.png'),
    frame: false,
    //titleBarStyle: 'customButtonsOnHover',
    webPreferences: {
      nodeIntegration: true,
    },
  });

  // and load the index.html of the app.
  mainWindow.loadURL('file://' + __dirname + '/app.html'); // eslint-disable-line no-path-concat
  mainWindow.webContents.executeJavaScript(
    // We use this so that RN can keep relative JSX __source filenames
    // but "click to open in editor" still works. js1 passes project roots
    // as the argument to DevTools.
    'window.devtools.setProjectRoots(' + JSON.stringify(projectRoots) + ')'
  );

  // Emitted when the window is closed.
  mainWindow.on('closed', function() {
    mainWindow = null;
  });
});