ThreadSafeTestsListener.scala

import sbt._
import sbt.testing.Event
import scala.collection.{concurrent, mutable}

class ThreadSafeTestsListener extends TestReportListener {
  val groups = concurrent.TrieMap.empty[String, TestGroup]

  class TestGroup(val name: String) {
    val events = new mutable.ArrayBuffer[Event] // does this need to be an ArrayBlockingQueue?
  }

  def startGroup(name: String) {
    groups.putIfAbsent(name, new TestGroup(name))
  }

  def testEvent(event: TestEvent) {
    // if all events correspond to one group and we had `name` on event we could do
    //   groups(event.name) ++= event.detail
    // but we don't, so we handle each individual detail item individually
    for (e <- event.detail) {
      val name = e.fullyQualifiedName // does this always corresponds to the group name?
      groups(name).events += e
    }
  }

  def endGroup(name: String, result: TestResult.Value) {
    groups.remove(name) match {
      case Some(group) => // do something with group.events
      case None =>
    }
  }

  def endGroup(name: String, t: Throwable) {
    groups.remove(name)
  }

}