Problem 2/30 of LeetCode 30-day challenge

happyNumber.js

let isHappy = (inputNum) => {
  // keep track of permutations
  let unhappyNums = [];
  let newSum = inputNum;
  
  // while the inputNum is not in the array
  while(!unhappyNums.includes(newSum)) {
    unhappyNums.push(newSum);
    // calculate new sum by converting to str, 
    // split by character then add the sum of each squared digit
    newSum = newSum.toString().split('').reduce((acc, num) => {
        return acc + (parseInt(num) ** 2);
    }, 0);  
    
    if(newSum === 1){ 
    // if that sum is 1 return true
      return true;
    };
  }
  
  // if inputNum is found in array, 
  // while loop will not start
  // return false
  return false;
};