testing Arduino serial interaction

SerialTest.ino

const int TESTPIN = 11;
String label = "Tick";
char buffer[33];

void setup() {
  // put your setup code here, to run once:
  pinMode(TESTPIN, OUTPUT);
  Serial.begin(9600);
}

void loop() {

  int index = 0;
  bool hasData = false;

  while (Serial.available() > 0) {
    hasData = true;
    buffer[index] = Serial.read();
    index++;
    if (index >= 32) {
      break;
    }
  }
  buffer[index] = "\0";

  if (hasData == true) {
    label = buffer;
    label.trim();
  }
  
  
  digitalWrite(TESTPIN, HIGH);
  delay(500);
  digitalWrite(TESTPIN, LOW);
  delay(500);
  Serial.println(label);
}