const listDeviceIds = async () => navigator.mediaDevices.enumerateDevices()
    .then(devices => devices.map(device => device.deviceId))
    .then(ids => ids.join(","));

const go = async () => {
  const devicesThen = await listDeviceIds()
  console.log(devicesThen)
  const devicesNow = await new Promise(resolve => {
    setTimeout(() => {
        resolve(listDeviceIds())
    }, 5000)
  })
  console.log(devicesNow)
  console.log("Equal?", devicesNow === devicesThen)
}

go()