Palindrome substring of string

function palindromeSubstring(str) {
  let palindromeArr = [];
  for (let i = 0; i < str.length; i++) {
    let low = i;
    let high = str.length - 1;
    let endIndex = high;
    while (low <= high) {
      if (str[low] == str[high]) {
        low++;
        high--;
      } else {
        if (low == i) {
          high--;
        }
        endIndex = high;
        low = i;
      }
    }
    palindromeArr.push(str.substring(i, endIndex + 1));
  }
  return palindromeArr;
}

console.log(palindromeSubstring("abaab"));
console.log(palindromeSubstring("abcd"));
console.log(palindromeSubstring("acbcdcb"));
console.log(palindromeSubstring("abccba"));
console.log(palindromeSubstring("racecar"));
console.log(palindromeSubstring("aaaa"));
console.log(palindromeSubstring("aabbaa"));