See https://github.com/nodejs/node/blob/master/lib/dns.js#L333

exports.ADNAME = 'EADNAME';

This line defines the error code ADNAME as 'EADNAME'. Shouldn't it be BADNAME and 'EBADNAME' respectively?

exports.BADNAME = 'EBADNAME';