locutus/esm/powershell/string/trimstart.js

Locutus other languages' standard libraries to JavaScript for fun and educational purposes

function escapeForCharClass(chars) {
    return chars.replace(/[\\\]^/-]/g, '\\$&');
}
export function trimstart(str, chars) {
    //      discuss at: https://locutus.io/powershell/trimstart/
    // parity verified: PowerShell 7.4
    //     original by: Kevin van Zonneveld (https://kvz.io)
    //       example 1: trimstart('  hello  ')
    //       returns 1: 'hello  '
    //       example 2: trimstart('__hello__', '_')
    //       returns 2: 'hello__'
    const value = String(str);
    if (chars === undefined) {
        return value.trimStart();
    }
    if (chars === '') {
        return value;
    }
    return value.replace(new RegExp(`^[${escapeForCharClass(chars)}]+`, 'g'), '');
}