Error bebop.js : Cannot read property 'readUInt8' of undefined

[kolki]

i have encountered this error

TypeError: Cannot read property 'readUInt8' of undefined
at Bebop._packetReceiver (/home/kit/node_modules/node-bebop/lib/bebop.js:301:43)
at emitTwo (events.js:87:13)
at Socket.emit (events.js:172:7)
at UDP.onMessage (dgram.js:480:8)

as i test any command.

in fact i modify bebop.js like this

line 307 FROM

 if ( networkFrame.id === constants.BD_NET_DC_EVENT_ID || networkFrame.id === constants.BD_NET_DC_NAVDATA_ID){

TO

 if ( (networkFrame.id === constants.BD_NET_DC_EVENT_ID ||
  networkFrame.id === constants.BD_NET_DC_NAVDATA_ID) && networkFrame.data !==  undefined) 

it seems sometime data field have lengfh but is empty.

{ type: 4,
  id: 126,
  seq: 53,
  size: 15,
  data: <Buffer 01 04 0f 00 03 00 00 00> }
{ type: 4, id: 126, seq: 54, size: 7 }
/home/kit/node_modules/node-bebop/lib/bebop.js:307
    var commandProject = networkFrame.data.readUInt8(0),
                                          ^

[arapocket]

Keep getting this as well

[Starystars67]

I too am getting this error at the moment

[Starystars67]

Making this edit to /lib/bebop.js allows things to work without this readUInt8 but i dont know what issues it might cause down the line:

`if (networkFrame.id === constants.BD_NET_DC_EVENT_ID ||
networkFrame.id === constants.BD_NET_DC_NAVDATA_ID) {

//var //commandProject = networkFrame.data.readUInt8(0),
    //commandClass = networkFrame.data.readUInt8(1),
    //commandId = networkFrame.data.readUInt16LE(2);

var offset = 4;
var args = {};
var event = null;


try {
  event = commands
    .first({id: commandProject}).class
    .first({id: commandClass}).cmd;
}
catch (err) {
  this.emit("unknown", networkFrame.data);
}

if (event) {

  if (event instanceof Array) {
    event = event[commandId];
    if (!event) {
      this.emit("unknown", networkFrame.data);
      return;
    }
  }

  if (typeof event.arg !== "undefined") {
    if (event.arg instanceof Array) {
      event.arg.forEach(function(arg) {
        if (types.hasOwnProperty(arg.type)) {
          args[arg.name] = types[arg.type]
            .read(networkFrame.data, offset, arg);

          offset += types[arg.type].length;
        }
      });
    }
    else if (event.arg instanceof Object) {
      if (types.hasOwnProperty(event.arg.type)) {
        args[event.arg.name] = types[event.arg.type]
          .read(networkFrame.data, offset, event.arg);
      }
    }
  }

  this.emit(event.name, args);
}

/*switch (commandProject) {
  case constants.ARCOMMANDS_ID_PROJECT_COMMON:
    switch (commandClass) {
      case constants.ARCOMMANDS_ID_COMMON_CLASS_COMMONSTATE:
        switch (commandId) {
          case constants.ARCOMMANDS_ID_COMMON_COMMONSTATE_CMD_BATTERYSTATECHANGED:
            this.navData.battery = networkFrame.data.readUInt8(4);
            this.emit("battery", this.navData.battery);
            break;
        }
        break;
    }
    break;
  case constants.ARCOMMANDS_ID_PROJECT_ARDRONE3:
    switch (commandClass) {
      case constants.ARCOMMANDS_ID_ARDRONE3_CLASS_PILOTINGSTATE:
        switch (commandId) {
          case constants.ARCOMMANDS_ID_ARDRONE3_PILOTINGSTATE_CMD_FLATTRIMCHANGED:
            break;
          case constants.ARCOMMANDS_ID_ARDRONE3_PILOTINGSTATE_CMD_FLYINGSTATECHANGED:
            switch (networkFrame.data.readInt32LE(4)) {
              case constants.ARCOMMANDS_ARDRONE3_PILOTINGSTATE_FLYINGSTATECHANGED_STATE_LANDED:
                this.navData.flyingState = { landed: true };
                this.emit("landed");
                break;
              case constants.ARCOMMANDS_ARDRONE3_PILOTINGSTATE_FLYINGSTATECHANGED_STATE_TAKINGOFF:
                this.navData.flyingState = { takingOff: true };
                this.emit("takingOff");
                break;
              case constants.ARCOMMANDS_ARDRONE3_PILOTINGSTATE_FLYINGSTATECHANGED_STATE_HOVERING:
                this.navData.flyingState = { hovering: true };
                this.emit("hovering");
                break;
              case constants.ARCOMMANDS_ARDRONE3_PILOTINGSTATE_FLYINGSTATECHANGED_STATE_FLYING:
                this.navData.flyingState = { flying: true };
                this.emit("flying");
                break;
              case constants.ARCOMMANDS_ARDRONE3_PILOTINGSTATE_FLYINGSTATECHANGED_STATE_LANDING:
                this.navData.flyingState = { landing: true };
                this.emit("landing");
                break;
              case constants.ARCOMMANDS_ARDRONE3_PILOTINGSTATE_FLYINGSTATECHANGED_STATE_EMERGENCY:
                this.navData.flyingState = { emergency: true };
                this.emit("emergency");
                break;
            }
            break;
        }
        break;
    }
    break;
}*/

}`

[evilqubit]

so what is a permanent fix ?

[alishibli97]

Did you find any solution?? please