@nodesecure/domain-check/src/domainExpirationDate.js

NodeSecure (npm) domain-check analysis package

// Node.js Dependencies
import net from "node:net";
import streamConsumers from "node:stream/consumers";

// CONSTANTS
const kDefaultSocketServer = "whois.iana.org";

function* lazyParseIanaWhoisResponse(rawResponseStr) {
  /** @type {string[]} */
  const lines = rawResponseStr.split(/\r?\n/);

  for (const line of lines) {
    const safeLine = line.trim();

    if (safeLine !== "" && safeLine.charAt(0) !== "%" && safeLine.includes(":")) {
      const [key, value] = safeLine.split(":");

      yield [key.trimStart(), value.trimStart()];
    }
  }
}

export async function whois(domain, server = kDefaultSocketServer) {
  const client = new net.Socket();
  setImmediate(() => client.connect(43, server, () => client.write(`${domain}\r\n`)));

  const rawResponseStr = await streamConsumers.text(client);
  const response = Object.fromEntries(lazyParseIanaWhoisResponse(rawResponseStr));

  if ("refer" in response && response.refer !== server) {
    return whois(domain, response.refer);
  }

  return response["Registry Expiry Date"];
}