Is autoSelectFamily possible to counteract Node.js 18 dns.lookup changes?

[MikeMcC399]

Is it possible to use autoSelectFamily from socket.connect(options[, connectListener]) of Node.js 18 and later to check if a development server is running or not, when the hostname is localhost and you don't know beforehand if it is listening on the IPv4 127.0.0.1 loopback address or on the IPv6 ::1 loopback address?

This is turning out to be a problem with some dev servers, for instance Angular or Vite, as GitHub has now migrated their runners to use Node.js 18 as default and the change in logic in Node.js has kicked in. Node.js 17.0.0 introduced the change in nodejs/node@1b2749ecbe "(SEMVER-MAJOR) dns: default to verbatim=true in dns.lookup()". (See History in dns.lookup(hostname[, options], callback).)

[sindresorhus]

Got already has a solution for this. You can use the dnsLookupIpVersion option to force IPv4:

await got('http://localhost:3000', {
	dnsLookupIpVersion: 4
});

Alternatively, use 127.0.0.1 directly instead of localhost.

The autoSelectFamily option could be added as a pass-through to Node.js, but given the existing workarounds, I don't think it's necessary.