verificator/es/rules/digits.js

Client and server-side validation JavaScript library

import requireParameterCount from './helpers/requireParameterCount';
const validate = (attribute, value, parameters, validator) => {
    requireParameterCount(1, parameters, 'digits');
    const [length] = parameters;
    const str = String(value);
    return /^[0-9]*$/.test(str) && str.length === Number(length);
};
export default validate;