import dns from 'dns'; export function isEmailDomainValid(email) { const domain = email.split('@')[1]; return new Promise((resolve, reject) => { dns.lookup(domain, (err, address) => { if (err) { reject(err); } else { const isIPAddress = /^\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}$/.test(address); resolve(isIPAddress); } }); }); } export function isValidEmail(email) { const emailRegex = /\S+@\S+\.\S+/; return emailRegex.test(email); } export function isNumber(x) { return /^-?[\d.]+(?:e-?\d+)?$/.test(x); } export function isPhoneNumber(phone) { const phoneRegex = /^\d{10}$/; return phoneRegex.test(phone); }