When mqtt client gets offline, an error message is trown in the console

[GerganaGeorgiev]

Hello,

I'm developing Next Js 14 app, which usses mqtt as real time data broker.
I'm using simple setup for connecting to mqtt:

const mqttClient: MqttClient = mqtt.connect("ws://my-broker-uri-83", {
  reconnectPeriod: 1000,
  connectTimeout: 30 * 1000,
  keepalive: 60,
});

and after that I'm exposing the mqttClient module to another place, where it's used. (In that particular case in Route Handler GET function).

Everything is working fine, till the moment the broker gets disconnected, which happens every couple of minutes. Then I'm getting this error:

 ⨯ uncaughtException: TypeError: bufferUtil.mask is not a function
    at module.exports.mask (webpack-internal:///(rsc)/./node_modules/ws/lib/buffer-util.js:121:23)
    at Sender.frame (webpack-internal:///(rsc)/./node_modules/ws/lib/sender.js:138:7)
    at Sender.send (webpack-internal:///(rsc)/./node_modules/ws/lib/sender.js:359:16)
    at WebSocket.send (webpack-internal:///(rsc)/./node_modules/ws/lib/websocket.js:476:18)
    at duplex._write (webpack-internal:///(rsc)/./node_modules/ws/lib/stream.js:151:8)
    at doWrite (node:internal/streams/writable:590:12)
    at clearBuffer (node:internal/streams/writable:774:7)
    at onwrite (node:internal/streams/writable:644:7)
    at afterWrite (node:internal/streams/writable:701:5)
    at afterWriteTick (node:internal/streams/writable:687:10)
    at process.processTicksAndRejections (node:internal/process/task_queues:81:21)

It seems like the reconnection works, because I'm getting logs for those events and the app gets automatically reconnected after a few moments after the error has been thrown.
The error is shown only on the server side console, there is no error in the client.
Can you please provide me with some kind of solution or at least ideas what could cause the issue?

[GerganaGeorgiev]

It seems that I had to additionally install the bufferutil library, which is used by ws, which is used by mqtt. This solved my problem.

[robertsLando]

@GerganaGeorgiev this is strange, I think you had some issues while installing ws because if that's a dep of ws it should come with it

[GerganaGeorgiev]

Yes, I guess this happened, because I initially had ws npm packet installed, which I removed. But multiple deleting and installing node_modules didn't solve it.