Tests for serialport on node v0.10.x , the outputs are the same for both v0.8.21 and v0.10.2

Output

data received: Th
data received: is i
data received: s so
data received: me s
data received: eria
data received: l da
data received: ta

data received: T
data received: his 
data received: is s
data received: ome 
data received: seri
data received: al d
data received: ata
data received: 

data received: This
data received:  is 
data received: some
data received:  ser
data received: ial 
data received: data
data received: 

data received: Thi
data received: s is
data received:  som
data received: e se
data received: rial
data received:  dat
data received: a

data received: Th
data received: is i
data received: s so
data received: me s
data received: eria
data received: l d
data received: ata
data received: 

serialTest.js

var serialport = require( 'serialport' );
var SerialPort = serialport.SerialPort;

var sp = new SerialPort( '/dev/cu.usbmodemfa1331', {

  baudrate : 9600
} );


sp.on('data', function(data) {
	console.log('data received: ' + data);
});
sp.write("ls\n", function(err, results) {
	console.log('err ' + err);
	console.log('results ' + results);
});

sketch.ino

void setup(){
  Serial.begin( 9600 );
}

void loop(){
   Serial.println( "This is some serial data" );
   delay( 1000 );
}