ANSWER: I've finally got it, turns out I was also looking in the wrong place for the logger file. it places it in the main folder instead of the folder the javascript was in. The code that worked for me was:

var fs = require('fs');
var log = fs.createWriteStream('nodelogger.txt', {flags: 'a', encoding: 'utf-8',mode: 0666});

server.listen(8888);

app.use("/", express.static(__dirname + '/files'));


io.sockets.on('connection', function (socket) {
  socket.on('msg', function (data) {
    io.sockets.emit('new', data);
    log.on('error', function (err) {
      console.log(err);
    });

    console.log(data);
    log.on('error', function(e) { console.error(e); });
    var newdata = JSON.stringify(data);
    log.write(newdata += "\r\n")
  });
});

I'm totally new to Node.js so I could really use some help. I'm trying to log messages from the chat I'm making So far I have this:

var fs = require('fs');
var log = fs.createWriteStream('nodelogger.txt', {'flags': 'a'});

server.listen(8888);

app.use("/", express.static(__dirname + '/files'));


io.sockets.on('connection', function (socket) {
  socket.on('msg', function (data) {
    io.sockets.emit('new', data);
    log.write(data);
    log.on('error', function (err) {
      console.log(err);
    });
  });
});

But I keep getting this error:

events.js:72
        throw er; // Unhandled 'error' event
              ^
TypeError: Invalid non-string/buffer chunk
    at validChunk (_stream_writable.js:150:14)
    at WriteStream.Writable.write (_stream_writable.js:179:12)
    at Socket.<anonymous> (/Users/test/Desktop/Chat/app.js:16:9)
    at Socket.EventEmitter.emit [as $emit] (events.js:95:17)
    at SocketNamespace.handlePacket (/Users/test/Desktop/Chat/node_modules/socket.io/lib/namespace.js:335:22)
    at Manager.onClientMessage (/Users/test/Desktop/Chat/node_modules/socket.io/lib/manager.js:488:38)
    at WebSocket.Transport.onMessage (/Users/test/Desktop/Chat/node_modules/socket.io/lib/transport.js:387:20)
    at Parser.<anonymous> (/Users/test/Desktop/Chat/node_modules/socket.io/lib/transports/websocket/hybi-16.js:39:10)
    at Parser.EventEmitter.emit (events.js:95:17)
    at finish (/Users/test/Desktop/Chat/node_modules/socket.io/lib/transports/websocket/hybi-16.js:288:16)

And I have no idea what it means, can't find it anywhere either. Does anybody have an idea what I'm doing wrong? Thanks in advance!

ANSWER: I've finally got it, turns out I was also looking in the wrong place for the logger file. it places it in the main folder instead of the folder the javascript was in. The code that worked for me was:

var fs = require('fs');
var log = fs.createWriteStream('nodelogger.txt', {flags: 'a', encoding: 'utf-8',mode: 0666});

server.listen(8888);

app.use("/", express.static(__dirname + '/files'));


io.sockets.on('connection', function (socket) {
  socket.on('msg', function (data) {
    io.sockets.emit('new', data);
    log.on('error', function (err) {
      console.log(err);
    });

    console.log(data);
    log.on('error', function(e) { console.error(e); });
    var newdata = JSON.stringify(data);
    log.write(newdata += "\r\n")
  });
});

I'm totally new to Node.js so I could really use some help. I'm trying to log messages from the chat I'm making So far I have this:

var fs = require('fs');
var log = fs.createWriteStream('nodelogger.txt', {'flags': 'a'});

server.listen(8888);

app.use("/", express.static(__dirname + '/files'));


io.sockets.on('connection', function (socket) {
  socket.on('msg', function (data) {
    io.sockets.emit('new', data);
    log.write(data);
    log.on('error', function (err) {
      console.log(err);
    });
  });
});

But I keep getting this error:

events.js:72
        throw er; // Unhandled 'error' event
              ^
TypeError: Invalid non-string/buffer chunk
    at validChunk (_stream_writable.js:150:14)
    at WriteStream.Writable.write (_stream_writable.js:179:12)
    at Socket.<anonymous> (/Users/test/Desktop/Chat/app.js:16:9)
    at Socket.EventEmitter.emit [as $emit] (events.js:95:17)
    at SocketNamespace.handlePacket (/Users/test/Desktop/Chat/node_modules/socket.io/lib/namespace.js:335:22)
    at Manager.onClientMessage (/Users/test/Desktop/Chat/node_modules/socket.io/lib/manager.js:488:38)
    at WebSocket.Transport.onMessage (/Users/test/Desktop/Chat/node_modules/socket.io/lib/transport.js:387:20)
    at Parser.<anonymous> (/Users/test/Desktop/Chat/node_modules/socket.io/lib/transports/websocket/hybi-16.js:39:10)
    at Parser.EventEmitter.emit (events.js:95:17)
    at finish (/Users/test/Desktop/Chat/node_modules/socket.io/lib/transports/websocket/hybi-16.js:288:16)

And I have no idea what it means, can't find it anywhere either. Does anybody have an idea what I'm doing wrong? Thanks in advance!

• javascript
• node.js
• terminal
• entity-relationship
• throw

2 Answers 2

Here you can convert datatype to string and print it. It will work as expected.

Code Error Postman Error

I Found that I was parsing same key and value pair in Postman while hitting Application Programming Interface Resulting in Invalid non-string/buffer chunk