Store JValue into ObjectEvent

internal/util-logging/src/main/scala/sbt/internal/util/ConsoleAppender.scala

@@ -263,8 +263,8 @@ class ConsoleAppender private[ConsoleAppender] (
     }
   def objectEventToLines(oe: ObjectEvent[_]): Vector[String] =
     {
-      val tag = oe.tag
-      LogExchange.stringCodec[AnyRef](tag) match {
+      val contentType = oe.contentType
+      LogExchange.stringCodec[AnyRef](contentType) match {
         case Some(codec) => codec.showLines(oe.message.asInstanceOf[AnyRef]).toVector
         case _           => Vector(oe.message.toString)
       }

internal/util-logging/src/main/scala/sbt/internal/util/ManagedLogger.scala

@@ -42,7 +42,7 @@ class ManagedLogger(
       val tag = StringTypeTag[A]
       LogExchange.getOrElseUpdateJsonCodec(tag.key, implicitly[JsonFormat[A]])
       // println("logEvent " + tag.key)
-      val entry: ObjectEvent[A] = new ObjectEvent(level, v, channelName, execId, tag.key)
+      val entry: ObjectEvent[A] = ObjectEvent(level, v, channelName, execId, tag.key)
       xlogger.log(
         ConsoleAppender.toXLevel(level),
         new ObjectMessage(entry)

internal/util-logging/src/main/scala/sbt/internal/util/ObjectEvent.scala

@@ -4,12 +4,27 @@ package util
 
 import sbt.util.Level
 import sjsonnew.JsonFormat
+import sjsonnew.support.scalajson.unsafe.Converter
+import scala.json.ast.unsafe.JValue
 
 final class ObjectEvent[A](
   val level: Level.Value,
   val message: A,
   val channelName: Option[String],
   val execId: Option[String],
-  val tag: String
+  val contentType: String,
+  val json: JValue
 ) extends Serializable {
 }
+
+object ObjectEvent {
+  def apply[A: JsonFormat](
+    level: Level.Value,
+    message: A,
+    channelName: Option[String],
+    execId: Option[String],
+    contentType: String
+  ): ObjectEvent[A] =
+    new ObjectEvent(level, message, channelName, execId, contentType,
+      Converter.toJsonUnsafe(message))
+}