YAML test suite for rfc7672 DANE TLS implementations I (Juan) wrote while working for SparkPost.
The tests are written from the perspective of a component figuring out the list of mailhosts to connect to, using a recursive resolver. Each case starts with either "nexthop" to indicate a domain subject to MX resolution, or "mailhost" for a domain not subject to that (such as a configured mailhost). Its output is a list named "mailhosts", with various properties indicating whether opportunistic DANE TLS applies to specific host, what the reference identifiers and TLSA records should apply, etc.