electron/spec/fixtures/pages/permissions/notification.html

<script>
var n1 = new Notification('Electron Notification.requestPermission test 1')
var n2 = new Notification('Electron Notification.requestPermission test 2')
Notification.requestPermission().then((result) => {
  n1.close()
  n2.close()

  require('electron').ipcRenderer.send('message', result)
})
</script>