Sending string over serial to nodejs app. Why does it get chunked?
It seems I needed to add a parser to SerialPort nodejs module, in order to specify how the input should be treated. 

I changed my code to this:

var SerialPort = require('serialport')
var Readline = SerialPort.parsers.Readline

var serialPort = new SerialPort('/dev/ttyACM0', {
  baudrate: 9600
})

var parser = new Readline()
serialPort.pipe(parser)
parser.on('data', function (data) {
  console.log('data received: ' + data)
})

serialPort.on('open', function () {
  console.log('Communication is on!')
})


Basically, I'm specifying a Readline parser, which matches with the Serial.println function calls on my arduino sketch. Now the console output works as expected:

Communication is on!
data received: Found ILI9341 LCD driver