Extend metadata model for published_by (#193)

* extend metadata model for published_by

Signed-off-by: Chanh Nguyen <chanh.nguyen@zalando.fi>

src/main/scala/org/zalando/kanadi/api/Events.scala

@@ -151,11 +151,12 @@ final case class Metadata(eid: EventId = EventId.random,
                           flowId: Option[FlowId] = None,
                           partition: Option[Partition] = None,
                           partitionCompactionKey: Option[PartitionCompactionKey] = None,
-                          spanCtx: Option[SpanCtx] = None)
+                          spanCtx: Option[SpanCtx] = None,
+                          publishedBy: Option[PublishedBy] = None)
 
 object Metadata {
 
-  implicit val metadataEncoder: Encoder[Metadata] = Encoder.forProduct9(
+  implicit val metadataEncoder: Encoder[Metadata] = Encoder.forProduct10(
     "eid",
     "occurred_at",
     "event_type",
@@ -164,10 +165,11 @@ object Metadata {
     "flow_id",
     "partition",
     "partition_compaction_key",
-    "span_ctx"
+    "span_ctx",
+    "published_by"
   )(x => Metadata.unapply(x).get)
 
-  implicit val metadataDecoder: Decoder[Metadata] = Decoder.forProduct9(
+  implicit val metadataDecoder: Decoder[Metadata] = Decoder.forProduct10(
     "eid",
     "occurred_at",
     "event_type",
@@ -176,7 +178,8 @@ object Metadata {
     "flow_id",
     "partition",
     "partition_compaction_key",
-    "span_ctx"
+    "span_ctx",
+    "published_by"
   )(Metadata.apply)
 }
 

src/main/scala/org/zalando/kanadi/models/PublishedBy.scala

@@ -0,0 +1,13 @@
+package org.zalando.kanadi.models
+
+import io.circe.syntax._
+import io.circe.{Decoder, Encoder}
+
+final case class PublishedBy(name: String) extends AnyVal
+
+object PublishedBy {
+  implicit val publishedByEncoder: Encoder[PublishedBy] =
+    Encoder.instance[PublishedBy](_.name.asJson)
+  implicit val publishedByDecoder: Decoder[PublishedBy] =
+    Decoder[String].map(PublishedBy.apply)
+}

src/test/scala/org/zalando/kanadi/api/JsonSpec.scala

@@ -10,7 +10,7 @@ import org.specs2.specification.core.SpecStructure
 import io.circe._
 import io.circe.parser._
 import io.circe.syntax._
-import org.zalando.kanadi.models.{EventId, SpanCtx}
+import org.zalando.kanadi.models.{EventId, SpanCtx, PublishedBy}
 import java.time.OffsetDateTime
 
 import io.circe.CursorOp.DownField
@@ -28,7 +28,9 @@ class JsonSpec extends Specification {
   val uuid      = UUID.randomUUID()
   val testEvent = SomeEvent("Bart", "Simpson", uuid)
   val now       = OffsetDateTime.now()
-  val md        = Metadata(eid = EventId(UUID.fromString("4ae5011e-eb01-11e5-8b4a-1c6f65464fc6")), occurredAt = now)
+  val md = Metadata(eid = EventId(UUID.fromString("4ae5011e-eb01-11e5-8b4a-1c6f65464fc6")),
+                    occurredAt = now,
+                    publishedBy = Some(PublishedBy("bart_simpson")))
 
   val coreEventJson = s"""
     "first_name": "Bart",
@@ -37,7 +39,7 @@ class JsonSpec extends Specification {
   """
 
   val metadata =
-    s""""eid": "4ae5011e-eb01-11e5-8b4a-1c6f65464fc6", "occurred_at": ${now.asJson}"""
+    s""""eid": "4ae5011e-eb01-11e5-8b4a-1c6f65464fc6", "occurred_at": ${now.asJson}, "published_by": "bart_simpson""""
 
   val businessEventJson = s"""{
     "metadata": {$metadata},