Run results for: Trimming leading/trailing characters ex

Test name	Executions per second
✓ Index Version (Jason Larke)	1,206,625 Ops/sec
Boolean Filter Version (mbaer3000)	97,596 Ops/sec
trimStartEx	63,075 Ops/sec
Regex Version (leaf)	59,635 Ops/sec
Substring Version (Pho3niX83)	56,850 Ops/sec
Spread Version (Robin F.)	1,201 Ops/sec

Script Preparation code:

var TestString = '+'.repeat(200) + '='.repeat(20000) + '+'.repeat(200);

String.prototype.trimStartEx = function(chars = ['-', ' '])
{
  let result = this;
  while (true)
  {
    let resultLen = result.length;
    for (let i = 0; i < chars.length; i++) {
      if (result.indexOf(chars[i]) == 0)
        result = result.substring(1);
    }
    if (resultLen == result.length) {
      break;
    }
  }
  return result;
}

var regexTrim = function(str, ch) {
    if (ch === ']') ch = '\\]';
    else if (ch === '^') ch = '\\^';
    else if (ch === '\\') ch = '\\\\';
    return str.replace(new RegExp('^[' + ch + ']+|[' + ch + ']+$', 'g'), '');
};

function indexTrim(str, ch) {
    var start = 0, 
        end = str.length;

    while(start < end && str[start] === ch)
        ++start;

    while(end > start && str[end - 1] === ch)
        --end;

    return (start > 0 || end < str.length) ? str.substring(start, end) : str;
}

function booleanTrim(str, ch) {
    return str.split(ch).filter(Boolean).join(ch);
}

function spreadTrim(str, ch) {
    const first = [...str].findIndex(char => char !== ch);
    const last = [...str].reverse().findIndex(char => char !== ch);
    return str.substring(first, str.length - last);
}

function substringTrim(str, ch) {
    while(str.charAt(0)==ch) {
        str = str.substring(1);
    }

    while(str.charAt(str.length-1)==ch) {
        str = str.substring(0,str.length-1);
    }

    return str;
}

Tests:

Index Version (Jason Larke)
indexTrim(TestString, '+');
Regex Version (leaf)
regexTrim(TestString, '+')
Boolean Filter Version (mbaer3000)
booleanTrim(TestString, '+')
Spread Version (Robin F.)
spreadTrim(TestString, '+')
Substring Version (Pho3niX83)
substringTrim(TestString, '+')
trimStartEx
TestString.trimStartEx('+')

Run results for: Trimming leading/trailing characters ex

Index Version (Jason Larke)

Regex Version (leaf)

Boolean Filter Version (mbaer3000)

Spread Version (Robin F.)

Substring Version (Pho3niX83)

trimStartEx