[scalaz-stream] failing assertion

[Luciano Leggieri]

I have the following stream:

val stream: Process[Task, ByteVector] = ...

val s: Sink[Task, ByteVector] = sink.lift {
  _ => Task.now(()) // does nothing for the purpose of this example
}

val hashedStream = scalaz.stream.writer.logged(stream).drainW(s.pipeIn(scalaz.stream.hash.sha1))

and it's failing on this assertion

https://github.com/scalaz/scalaz-stream/blob/master/src/main/scala/scalaz/stream/io.scala#L308

It doesn't fail if I remove the writer. I think it's because scalaz.stream.hash.messageDigest emits on onComplete. 

It seems there is a law that says that a process cannot emit after it's been killed. Where can I find scalaz-stream laws? Any help is appreciated.

Thanks,

Luciano.

[Luciano Leggieri]

I've opened a PR that addresses this issue:

https://github.com/scalaz/scalaz-stream/pull/407

(also, it avoids wrapping an IOException inside another)