Randomize dataset by randomList of unique random values for GAS

randomize.js

function randomList(range, n) {
  //
  var checklist = [], out = [];
  // loop
  for (var i = 0; out.length < n; i++) {
    //
    var num = Math.floor((Math.random() * range));
    // if not in checklist
    if (checklist.indexOf(num) === -1) {
      //
      out.push(num);
      //
      checklist.push(num);
    }
  }
  //
  return out;
}

function randomize(data, n) {
  // out
  var out = [], row, num;
  // random numbers
  var list = randomList(data.length, n);
  // loop
  for (var i = 0; i < list.length; i++) {
    //
    num = list[i];
    row = data[num];
    //
    out.push(row);
  }
  //
  return out;
}