BoardStateRandomTest.scala

  it should "do round-trip" in {
    forAll(initialBoardAndChangesGenerator) {
      case InitialBoardAndChanges(initialBoard, changes) =>
        lazy val boardAndEventsStream: Stream[(BoardState, Seq[TaskEvent])] =
          (initialBoard, Nil) #::
            (boardAndEventsStream zip changes).map {
              case ((prevBoard, events), changedBoard) =>
                val newAddedEvents = prevBoard.diff(changedBoard)
                (changedBoard, newAddedEvents)
            }

        boardAndEventsStream.drop(1).foldLeft(initialBoard) {
          case (prevBoard, (boardAfterGeneratedChanges, events)) =>
            val boardAfterEventsAccumulation = events.foldLeft(prevBoard) { (board, event) =>
              board.plus(event)
            }
            withMoreReadeableClue(prevBoard, events, boardAfterGeneratedChanges, boardAfterEventsAccumulation) {
              boardAfterEventsAccumulation shouldEqual boardAfterGeneratedChanges
            }
            boardAfterEventsAccumulation
        }
    }
  }