livr/lib/rules/modifiers/leave_only.js

Lightweight validator supporting Language Independent Validation Rules Specification

const util = require('../../util');

function leave_only(chars) {
    const escapedChars = util.escapeRegExp(chars);
    const re = new RegExp(`[^${escapedChars}]`, 'g');

    return (value, params, outputArr) => {
        if (util.isNoValue(value) || typeof value === 'object') return;

        const strValue = typeof value === 'string' ? value : String(value);
        outputArr.push(strValue.replace(re, ''));
    };
}

module.exports = leave_only;