preload.js

// https://medium.com/cameron-nokes/how-to-create-a-hybrid-electron-app-53553ece0889

// in preload scripts, we have access to node.js and electron APIs
// the remote web app will not have access, so this is safe
const { ipcRenderer, ipc, remote } = require('electron');
const storage = require('electron-json-storage');
const ReconnectingWebSocket = require('rws').ReconnectingWebSocket;

init();

function init() {
    console.log('PRELOADING');
  // Expose a bridging API to by setting an global on `window`.
  // We'll add methods to it here first, and when the remote web app loads,
  // it'll add some additional methods as well.
  //
  // !CAREFUL! do not expose any functionality or APIs that could compromise the
  // user's computer. E.g. don't directly expose core Electron (even IPC) or node.js modules.
  window.Bridge = {
      getGlobal: remote.getGlobal,
      ipcRenderer: ipcRenderer,
      ReconnectingWebSocket: ReconnectingWebSocket,
      storage: {
          get: storage.get,
          getMany: storage.getMany,
          set: storage.set
      }
  }
}