Zero-width char exploit

index.js

const toZW = (text) => {
        const zeroPad = num => '00000000'.slice(String(num).length) + num;

  const textToBinary = username => (
    username.split('').map(char => zeroPad(char.charCodeAt(0).toString(2))).join(' ')
  );

  const binaryToZeroWidth = binary => (
    binary.split('').map((binaryNum) => {
      const num = parseInt(binaryNum, 10);
      if (num === 1) {
        return ''; // invisible ​
      } else if (num === 0) {
        return ''; // invisible ‌
      }
      return '‍'; // invisible ‍
    }).join('') // invisible 
  );

  const binaryUsername = textToBinary(username);
  const zeroWidthUsername = binaryToZeroWidth(binaryUsername);
  return zeroWidthUsername;
}

console.log( "'" + toZW('ls') + "'" );