when the password is incorrent,only close event, no error event

[liu-xinhui]

const mqtt = require("mqtt");
        const client = mqtt.connect("ws://third.elevatorstar.com:7004/mqtt", {
          clientId: this.device.id,
          username: this.device.id,
          password: this.device.secret + "1",
          reconnectPeriod: 0,
        });
        client.on("connect", function() {
          console.log("connect");
        });

        client.on("close", () => {
          console.log("close");
        });

        client.on("error", function(error) {
          console.log(error);
        });

The error event no call when password is incorrent

[liu-xinhui]

if i enable reconnect,only reconnect and close event.
When the error event call?

[liu-xinhui]

when the password is incorrent, 4.3.4 no error event.but 4.2.1 is no this problem

this is the 4.2.1 error message，4.3.4 no this

Error: Connection refused: Bad username or password
    at MqttClient._handleConnack (client.js:1184)
    at MqttClient._handlePacket (client.js:424)
    at work (client.js:321)
    at Writable.writable._write (client.js:335)
    at doWrite (_stream_writable.js:428)
    at writeOrBuffer (_stream_writable.js:417)
    at Writable.write (_stream_writable.js:334)
    at Duplexify.ondata (_stream_readable.js:619)
    at Duplexify.emit (events.js:153)
    at addChunk (_stream_readable.js:291)

[liu-xinhui]

I have try 4.3.4, 4.3.0, 4.2.8, 4.2.6，4.2.1.
only 4.2.1 has the error msg. This big problem has occured a year ago, but no one find？

[caoyawu]

I tested 4.3.4, it's work well and i got the error message

[liu-xinhui]

@caoyawu you can try my server，ws://121.40.115.160:7024/mqtt

[caoyawu]

@liu-xinhui I get "Connection refused: Not authorized" for "ws://121.40.115.160:7024/mqtt"

[liu-xinhui]

http://jsrun.net/Fj9Kp/edit

you can try online,also only close,no error

[caoyawu]

[liu-xinhui]

@caoyawu
It should print error message every time， not sometimes print or sometimes not.
I have tried reconnect. Fortunately, you can get an error after try many times.
unfortunately, there are no error after hundreds of times

you can change https://unpkg.com/mqtt@4.3.5/dist/mqtt.min.js to https://unpkg.com/mqtt@4.2.1/dist/mqtt.min.js
will always show error msg.

[YoDaMa]

@liu-xinhui can you verify that the MQTT spec defines this behavior. I'm wondering if the behavior you expected in 4.2.1 but no longer see in more recent versions was a bug.

[Karl-Sparticle]

It happen to me also for 4.3.7.
I have try this version https://unpkg.com/mqtt@4.2.1/dist/mqtt.min.js. There is error event if default options was used.

[robertsLando]

MQTT 5.0.0 BETA is now available! Try it out and give us feedback: npm i mqtt@beta. It may fix your issues

[robertsLando]

Try to reproduce the issue with MQTT v5 and feel free to reopen in case the bug persists