text: /**
   * Given a number, replace this number with
   * the sum of its digits until we get to a one digit number.
   *
   * @param {Number} n
   * @return {Number}
   *
   * @example
   * For 100, the result should be 1 (1 + 0 + 0 = 1)
   * For 91, the result should be 1 (9 + 1 = 10, 1 + 0 = 1)
   *
   */
  function getSumOfDigits(n) {
    let newNumber = n;
    while (newNumber > 9) {
      newNumber = newNumber.toString().split('').reduce((acc, cur) => acc + +cur, 0);
    }
    return newNumber;
  }
  
  module.exports = getSumOfDigits;
  