var { app, BrowserWindow } = require("electron");
var mainWindow = null;

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

require("electron-reload")(__dirname);

app.on("ready", function() {
  mainWindow = new BrowserWindow({
    width: 225,
    height: 225,
    transparent: true,
    frame: false,
    alwaysOnTop: true,
    resizable: false
  });
  mainWindow.loadURL("file://" + __dirname + "/index.html");
  mainWindow.on("closed", function() {
    mainWindow = null;
  });
});

const { app, BrowserWindow } = require("electron");
var mainWindow = null;

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

require("electron-reload")(__dirname);

app.on("ready", function() {
  mainWindow = new BrowserWindow({
    width: 225,
    height: 225,
    transparent: true,
    frame: false,
    alwaysOnTop: true,
    resizable: false
  });
  mainWindow.loadURL("file://" + __dirname + "/index.html");
  mainWindow.on("closed", function() {
    mainWindow = null;
  });
});

Use const instead of var
Use const instead of var
