function parseStringNumbers (parser) {
  const length = parser.buffer.length - 1;
  var offset = parser.offset;
  var number = 0;
  var res = '';

  if (parser.buffer[offset] === 45) {
    res += '-';
    offset++;
  }

  while (offset < length) {
    var c1 = parser.buffer[offset++];
    if (c1 === 13) { // \r\n
      parser.offset = offset + 1;
      if (number !== 0) {
        res += number;
      }
      return res
    } else if (number > 429496728) {
      res += (number * 10) + (c1 - 48);
      number = 0;
    } else if (c1 === 48 && number === 0) {
      res += 0;
    } else {
      number = (number * 10) + (c1 - 48);
    }
  }
}
Used for integer numbers in case of the returnNumbers option

Reading the string as parts of n SMI is more efficient than
using a string directly.

@param {JavascriptRedisParser} parser
@returns {undefined|string}