Longest Substring that contains no repeated Characters Algorithm

Given a string s, find the length of the longest substring that contains no repeated characters.

Example Input: "nnNfdfdf" Answer: 4

const solution = (s) => {
    let left = 0;
    let right = 1;
    let max = 0;
    
    while (right <= s.length) {
        const substring = s.slice(left,right);
        
        max = Math.max(substring.length, max)
        
        const foundIndex = substring.indexOf(s[right])
        if (foundIndex !== -1){
            left += foundIndex+1;
            right++;
        } else {
            right++;
        }
    }
    return max
};

console.log(solution('nnNfdfdf'))