Run results for: Trimming leading/trailing characters

Run details:

User agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:84.0) Gecko/20100101 Firefox/84.0

Browser: Firefox 84

Operating system: Ubuntu

Device Platform: Desktop

Date tested: 2 years ago

Index Version (Jason Larke)

92K/s

Substring Version (Pho3niX83)

82K/s

Regex Version (leaf)

35K/s

Boolean Filter Version (mbaer3000)

20K/s

Spread Version (Robin F.)

356/s

View exact numbers

Test name	Executions per second
✓ Index Version (Jason Larke)	92,361 Ops/sec
Substring Version (Pho3niX83)	82,295 Ops/sec
Regex Version (leaf)	35,472 Ops/sec
Boolean Filter Version (mbaer3000)	20,263 Ops/sec
Spread Version (Robin F.)	356 Ops/sec

Script Preparation code:

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