electron/spec/fixtures/pages/media-id-reset.html

<script>
  const {ipcRenderer} = require('electron')
  navigator.mediaDevices.enumerateDevices().then((devices) => {
    return devices.map((device) => device.deviceId)
                  .filter((deviceId) => deviceId !== "default")
  }).then((deviceIds) => {
    ipcRenderer.send('deviceIds', deviceIds)
  })
</script>