diggy/dist/resolvers/doh-resolver.js

Multi-backend DNS resolver for Node.js/Browser — supports dig, DNS over HTTPS, and native Node.js DNS.

import { toDnsRecord } from "../utils/to-dns-record.js";
/**
 * Returns a DNS resolver that uses DNS over HTTPS (DoH) to resolve DNS records.
 *
 * ```ts
 * import { dohResolver } from "diggy";
 * const resolver = dohResolver("https://dns.google/resolve");
 * const records = await resolver("example.com", "A");
 * console.log(records);
 * ```
 *
 * > 💡 **Tip:** Find more public [DoH endpoints here](https://github.com/curl/curl/wiki/DNS-over-HTTPS)
 *
 * @param url - The URL of the DoH server to use (e.g., `https://dns.google/resolve`).
 * @group Resolvers
 */
export function dohResolver(url) {
    const dnsUrl = new URL(url);
    return async (host, type) => {
        dnsUrl.searchParams.set("name", host);
        dnsUrl.searchParams.set("type", type);
        const re = await fetch(dnsUrl, {
            headers: { accept: "application/dns-json" },
        });
        if (!re.ok) {
            throw new Error(`Error fetching DNS records for ${host}: ${re.status} ${re.statusText}`);
        }
        const json = (await re.json());
        if (!Array.isArray(json.Answer))
            return []; // No records found
        return json.Answer.map((record) => {
            return toDnsRecord({
                name: record.name,
                type: DNSTypeNumbers.get(record.type) ?? "UNKNOWN",
                ttl: record.TTL,
                data: record.data,
            });
        });
    };
}
const DNSTypeNumbers = new Map([
    [1, "A"],
    [2, "NS"],
    [5, "CNAME"],
    [6, "SOA"],
    [12, "PTR"],
    [15, "MX"],
    [16, "TXT"],
    [24, "SIG"],
    [25, "KEY"],
    [28, "AAAA"],
    [33, "SRV"],
    [35, "NAPTR"],
    [43, "DS"],
    [48, "DNSKEY"],
    [257, "CAA"],
]);