Given the class
case class OptSetString(strings: Option[Set[String]])
In 2.12.0 the schema incorrectly renders as
{"uniqueItems":true,"type":"string","items":{"type":"string"}}
In 2.7.2 the schema correctly renders as
{"uniqueItems":true,"type":"array","items":{"type":"string"}}
Moreover, the incorrect behavior cannot be overridden by adding an ArraySchema annotation
I suspect this is due to #174 and would apply recursively to any nested structure that eventually has a primitive as the first type parameter. Sorry about the late report on what is now an old change; we've only recently gone about updating our swagger codegen and encountered the problem