PubSub.subscribe('new_fib', new_fib => console.log(`new fib arrived!: ${new_fib}`));

let range = (n) => {
  let new_range = [];
  for(let i = 0; i < n; i += 1) {
    new_range.push(i);
  }
  return new_range
}

let first_ten_fib = range(10).map((num, i, arr) => {
  let new_fib;
  if(i === 0) {
    new_fib = 0;

  } else if(i === 1) {
    new_fib = 1;

  } else {
    new_fib =  arr[i - 1] + arr[ i - 2];

  }
  PubSub.publish('new_fib', new_fib);
  return new_fib;
});