import dns from 'dns'; import {send, sendError} from '../../../util/http'; import {NowRequest, NowResponse} from '@vercel/node'; 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, ): Promise { const {query} = req.query; if (!query || typeof query !== 'string') { 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 send(res, {availability: true}); } sendError(res, err); } }