var TestString = '+'.repeat(200) + '='.repeat(20000) + '+'.repeat(200);

​

function regexTrim(str, what) {

  const chars = [...(what ? what : '\0\t\n\v\r ')].map((c) => ([']', '^', '\\', '-'].includes(c) ? '\\' + c : c)).join('');

  return str.replace(new RegExp('^[' + chars + ']+|[' + chars + ']+$', 'gu'), '');

}

​

function indexTrim(str, what) {

  let end, start;

  const chars = [...str];

  const charsToTrim = [...(what ? what : '\0\t\n\v\r ')];

  start = 0;

  end = chars.length;

​

  while (start < end && charsToTrim.includes(chars[start])) {

    ++start;

  }

​

  while (end > start && charsToTrim.includes(chars[end - 1])) {

    --end;

  }

​

  return (start > 0 || end < chars.length) ? chars.slice(start, end).join('') : str.slice();

}

​

function booleanTrim(str, what) {

  let result;

  const chars = what ? what : '\0\t\n\v\r ';

  result = str;

  for (const c of chars) {

    result = result.split(c).filter(Boolean).join(c);

  }

  return result;

}

​

function spreadTrim(str, what) {

  const chars = [...str];

  const charsToTrim = [...(what ? what : '\0\t\n\v\r ')];

  const end = chars.reverse().findIndex((c) => !charsToTrim.includes(c));

  const start = chars.reverse().findIndex((c) => !charsToTrim.includes(c));

  return chars.slice(start, chars.length - end).join('');

}

​

function substringTrim(str, what) {

  const chars = what ? what : '\0\t\n\v\r ';

  while (chars.includes(String.fromCodePoint(str.codePointAt(0)))) {

    str = str.substring(1);

  }

​

  while (chars.includes(String.fromCodePoint(str.codePointAt(str.length - 1)))) {

    str = str.substring(0, str.length - 1);

  }

​

  return str;

}

​

function sliceTrim(str, what) {

  const chars = what ? what : '\0\t\n\v\r ';

  while (chars.includes(String.fromCodePoint(str.codePointAt(0)))) {

    str = str.slice(1);

  }

​

  while (chars.includes(String.fromCodePoint(str.codePointAt(str.length - 1)))) {

    str = str.slice(0, -1);

  }

​

  return str;

}