Script – 13-45 Feb 2

function palindromeIndex(s) {
  let re = /[\W_]/g;

  let lowRegStr = s.toLowerCase().replace(re, "").split("");
  let reverseStr = s.toLowerCase().replace(re, "").split("").reverse();
  let removed;
  let removedRev;

  if (lowRegStr.join("") === reverseStr.join("")) {
    return -1;
  }

  for (let i = 0, k = s.length - 1; i < s.length; i++, k--) {
    removed = lowRegStr.splice(i, 1);
    removedRev = reverseStr.splice(k, 1);

    if (lowRegStr.join("") === reverseStr.join("")) {
      return i;
    }
    lowRegStr.splice(i, 0, ...removed);
    reverseStr.splice(k, 0, ...removedRev);
  }

  return -1;
}
console.log(palindromeIndex("eye"));