import dns from 'dns' import { send, sendError, NowRequest, NowResponse } from '../util/http' function resolvePromise(hostname: string): Promise { return new Promise((resolve, reject) => { dns.resolve4(hostname, function(err, addresses) { if (err) return reject(err) resolve(addresses) }) }) } export default async function handler(req: NowRequest, res: NowResponse) { const { query } = req.query if (!query) { return sendError(res, new Error('no query given')) } try { const response = await resolvePromise(query) const availability = response && response.length > 0 ? false : true send(res, { availability }) } catch (err) { if (err.code === 'ENODATA' || err.code === 'ENOTFOUND') { return res.status(200).json({ availability: true }) } sendError(res, err) } }