RSSHub/lib/utils/valid-host.ts

/**
 * Check if a sub-domain is valid
 * @param {String} hostname sub-domain
 * @returns {Boolean} true if valid
 */
const isValidHost = (hostname?: string) => {
    if (typeof hostname !== 'string') {
        return false;
    }
    const regex = /^[\dA-Za-z]([\dA-Za-z-]{0,61}[\dA-Za-z])?$/;
    return regex.test(hostname);
};

export { isValidHost };