[ECO-5386] Implemented unit tests for ObjectMesssage json/msgpack serialization

1. Created ObjectMessageFixtures to represent dummy data in various formats
2. Added jackson-param dependency to fix jackson deserialization issue
3. Marked javaParameters as true on compilerOptions

Author: sacOO7

gradle/libs.versions.toml

@@ -26,6 +26,7 @@ turbine = "1.2.0"
 ktor = "3.1.3"
 jetbrains-annoations = "26.0.2"
 jackson-msgpack = "0.8.11" # Compatible with msgpack-core 0.8.11
+jackson-param = "2.18.0" # Compatible with jackson-msgpack
 
 [libraries]
 gson = { group = "com.google.code.gson", name = "gson", version.ref = "gson" }
@@ -56,6 +57,7 @@ ktor-client-core = { module = "io.ktor:ktor-client-core", version.ref = "ktor" }
 ktor-client-cio = { module = "io.ktor:ktor-client-cio", version.ref = "ktor" }
 jetbrains = { group = "org.jetbrains", name = "annotations", version.ref = "jetbrains-annoations" }
 jackson-msgpack = { group = "org.msgpack", name = "jackson-dataformat-msgpack", version.ref = "jackson-msgpack" }
+jackson-parameter-names = { group = "com.fasterxml.jackson.module", name = "jackson-module-parameter-names", version.ref = "jackson-param" }
 
 [bundles]
 common = ["msgpack", "vcdiff-core"]

live-objects/build.gradle.kts

@@ -14,6 +14,8 @@ dependencies {
     implementation(libs.bundles.common)
     implementation(libs.coroutine.core)
     implementation(libs.jackson.msgpack)
+    implementation(libs.jackson.parameter.names) // Add this
+
 
     testImplementation(kotlin("test"))
     testImplementation(libs.bundles.kotlin.tests)
@@ -45,4 +47,12 @@ tasks.register<Test>("runLiveObjectIntegrationTests") {
 
 kotlin {
     explicitApi()
+
+    /**
+     * Enables Jackson to map JSON property names to constructor parameters without use of @JsonProperty.
+     * Adds metadata params to bytecode class. Approach is completely binary-compatible with consumers of the library.
+     */
+    compilerOptions {
+        javaParameters = true
+    }
 }

live-objects/src/main/kotlin/io/ably/lib/objects/ObjectMessage.kt

@@ -214,13 +214,22 @@ internal data class ObjectOperation(
   val nonce: String? = null,
 
   /**
-   * The initial value for the object, encoded as a JSON string.
-   * This value should be used along with the nonce and timestamp to create the object ID.
-   * Frontdoor will use this to verify the object ID. After verification, the value will be
-   * decoded into the Map or Counter objects and the initialValue, nonce, and initialValueEncoding will be removed.
+   * The initial value bytes for the object. These bytes should be used along with the nonce
+   * and timestamp to create the object ID. Frontdoor will use this to verify the object ID.
+   * After verification the bytes will be decoded into the Map or Counter objects and
+   * the initialValue, nonce, and initialValueEncoding will be removed.
    * Spec: OOP3h
    */
-  val initialValue: String? = null,
+  @JsonAdapter(InitialValueJsonSerializer::class)
+  @JsonSerialize(using = InitialValueMsgpackSerializer::class)
+  @JsonDeserialize(using = InitialValueMsgpackDeserializer::class)
+  val initialValue: Binary? = null,
+
+  /** The initial value encoding defines how the initialValue should be interpreted.
+   * Spec: OOP3i
+   */
+  @Deprecated("Will be removed in the future, initialValue will be json string")
+  val initialValueEncoding: ProtocolMessageFormat? = null
 )
 
 /**

live-objects/src/main/kotlin/io/ably/lib/objects/Serialization.kt

@@ -2,15 +2,19 @@
 
 package io.ably.lib.objects
 
+import com.fasterxml.jackson.annotation.JsonCreator
+import com.fasterxml.jackson.annotation.JsonInclude
 import com.fasterxml.jackson.core.JsonGenerator
 import com.fasterxml.jackson.databind.DeserializationContext
 import com.fasterxml.jackson.databind.ObjectMapper
 import com.fasterxml.jackson.databind.SerializerProvider
+import com.fasterxml.jackson.module.paramnames.ParameterNamesModule
 import com.google.gson.*
 import org.msgpack.core.MessagePack
 import org.msgpack.core.MessagePacker
 import org.msgpack.core.MessageUnpacker
 import org.msgpack.jackson.dataformat.MessagePackFactory
+import org.msgpack.value.ImmutableMapValue
 import java.lang.reflect.Type
 import java.util.*
 
@@ -19,7 +23,11 @@ internal val gson: Gson = GsonBuilder().create()
 
 // Jackson ObjectMapper for MessagePack serialization (respects @JsonProperty annotations)
 // Caches type metadata and serializers for ObjectMessage class after first use, so next time it's super fast 🚀
-private val msgpackMapper = ObjectMapper(MessagePackFactory())
+// https://github.com/FasterXML/jackson-modules-java8/tree/3.x/parameter-names
+internal val msgpackMapper = ObjectMapper(MessagePackFactory()).apply {
+  registerModule(ParameterNamesModule(JsonCreator.Mode.PROPERTIES))
+  setSerializationInclusion(JsonInclude.Include.NON_NULL)
+}
 
 internal fun ObjectMessage.toJsonObject(): JsonObject {
   return gson.toJsonTree(this).asJsonObject
@@ -30,29 +38,15 @@ internal fun JsonObject.toObjectMessage(): ObjectMessage {
 }
 
 internal fun ObjectMessage.writeTo(packer: MessagePacker) {
-  // Jackson automatically creates the correct msgpack map structure
-  val msgpackBytes = msgpackMapper.writeValueAsBytes(this)
-
-  // Parse the msgpack bytes to get the structured value
-  val tempUnpacker = MessagePack.newDefaultUnpacker(msgpackBytes)
-  val msgpackValue = tempUnpacker.unpackValue()
-  tempUnpacker.close()
-
-  // Pack the structured value using the provided packer
-  packer.packValue(msgpackValue)
+  val msgpackBytes = msgpackMapper.writeValueAsBytes(this) // returns correct msgpack map structure
+  packer.writePayload(msgpackBytes)
 }
 
-internal fun MessageUnpacker.readObjectMessage(): ObjectMessage {
-  // Read the msgpack value from the unpacker
-  val msgpackValue = this.unpackValue()
-
-  // Convert the msgpack value back to bytes
-  val tempPacker = MessagePack.newDefaultBufferPacker()
-  tempPacker.packValue(msgpackValue)
-  val msgpackBytes = tempPacker.toByteArray()
-  tempPacker.close()
-
-  // Let Jackson deserialize the msgpack bytes back to ObjectMessage
+internal fun ImmutableMapValue.toObjectMessage(): ObjectMessage {
+  val msgpackBytes = MessagePack.newDefaultBufferPacker().use { packer ->
+    packer.packValue(this)
+    packer.toByteArray()
+  }
   return msgpackMapper.readValue(msgpackBytes, ObjectMessage::class.java)
 }
 
@@ -66,7 +60,7 @@ internal class DefaultLiveObjectSerializer : LiveObjectSerializer {
 
   override fun readMsgpackArray(unpacker: MessageUnpacker): Array<Any> {
     val objectMessagesCount = unpacker.unpackArrayHeader()
-    return Array(objectMessagesCount) { unpacker.readObjectMessage() }
+    return Array(objectMessagesCount) { unpacker.unpackValue().asMapValue().toObjectMessage() }
   }
 
   override fun writeMsgpackArray(objects: Array<out Any>?, packer: MessagePacker) {
@@ -101,7 +95,7 @@ internal class ObjectDataJsonSerializer : JsonSerializer<ObjectData>, JsonDeseri
       when (val v = value.value) {
         is Boolean -> obj.addProperty("boolean", v)
         is String -> obj.addProperty("string", v)
-        is Number -> obj.addProperty("number", v)
+        is Number -> obj.addProperty("number", v.toDouble())
         is Binary -> obj.addProperty("bytes", Base64.getEncoder().encodeToString(v.data))
         // Spec: OD4c5
         is JsonObject, is JsonArray -> {
@@ -132,7 +126,7 @@ internal class ObjectDataJsonSerializer : JsonSerializer<ObjectData>, JsonDeseri
         )
       }
       obj.has("string") -> ObjectValue(obj.get("string").asString)
-      obj.has("number") -> ObjectValue(obj.get("number").asNumber)
+      obj.has("number") -> ObjectValue(obj.get("number").asDouble)
       obj.has("bytes") -> ObjectValue(Binary(Base64.getDecoder().decode(obj.get("bytes").asString)))
       else -> throw JsonParseException("ObjectData must have one of the fields: boolean, string, number, or bytes")
     }
@@ -179,10 +173,32 @@ internal class ObjectDataMsgpackDeserializer : com.fasterxml.jackson.databind.Js
         )
       }
       node.has("string") -> ObjectValue(node.get("string").asText())
-      node.has("number") -> ObjectValue(node.get("number").numberValue())
+      node.has("number") -> ObjectValue(node.get("number").doubleValue())
       node.has("bytes") -> ObjectValue(Binary(node.get("bytes").binaryValue()))
       else -> throw IllegalArgumentException("ObjectData must have one of the fields: boolean, string, number, or bytes")
     }
     return ObjectData(objectId, value)
   }
 }
+
+internal class InitialValueJsonSerializer : JsonSerializer<Binary>, JsonDeserializer<Binary> {
+  override fun serialize(src: Binary, typeOfSrc: Type?, context: JsonSerializationContext?): JsonElement {
+    return JsonPrimitive(Base64.getEncoder().encodeToString(src.data))
+  }
+
+  override fun deserialize(json: JsonElement, typeOfT: Type?, context: JsonDeserializationContext?): Binary {
+    return Binary(Base64.getDecoder().decode(json.asString))
+  }
+}
+
+internal class InitialValueMsgpackSerializer : com.fasterxml.jackson.databind.JsonSerializer<Binary>() {
+  override fun serialize(value: Binary?, gen: JsonGenerator, serializers: SerializerProvider) {
+    gen.writeBinary(value?.data)
+  }
+}
+
+internal class InitialValueMsgpackDeserializer : com.fasterxml.jackson.databind.JsonDeserializer<Binary>() {
+  override fun deserialize(p: com.fasterxml.jackson.core.JsonParser, ctxt: DeserializationContext): Binary {
+    return Binary(p.binaryValue)
+  }
+}

live-objects/src/test/kotlin/io/ably/lib/objects/unit/ObjectMessageSerializationTest.kt

@@ -0,0 +1,78 @@
+package io.ably.lib.objects.unit
+
+import io.ably.lib.objects.gson
+import io.ably.lib.objects.msgpackMapper
+import io.ably.lib.objects.unit.fixtures.*
+import io.ably.lib.types.ProtocolMessage
+import io.ably.lib.types.ProtocolSerializer
+import io.ably.lib.util.Serialisation
+import kotlinx.coroutines.test.runTest
+import org.junit.Assert.assertEquals
+import org.junit.Test
+import kotlin.test.assertNotNull
+
+class ObjectMessageSerializationTest {
+
+  private val objectMessages = arrayOf(
+    dummyObjectMessageWithStringData(),
+    dummyObjectMessageWithBinaryData(),
+    dummyObjectMessageWithNumberData(),
+    dummyObjectMessageWithBooleanData(),
+    dummyObjectMessageWithJsonObjectData(),
+    dummyObjectMessageWithJsonArrayData()
+  )
+
+  @Test
+  fun testObjectMessageMsgPackSerialization() = runTest {
+    val protocolMessage = ProtocolMessage()
+    protocolMessage.action = ProtocolMessage.Action.`object`
+    protocolMessage.state = objectMessages
+
+    // Serialize the ProtocolMessage containing ObjectMessages to MsgPack format
+    val serializedProtoMsg = ProtocolSerializer.writeMsgpack(protocolMessage)
+    assertNotNull(serializedProtoMsg)
+
+    // Deserialize back to ProtocolMessage
+    val deserializedProtoMsg = ProtocolSerializer.readMsgpack(serializedProtoMsg)
+    assertNotNull(deserializedProtoMsg)
+
+    deserializedProtoMsg.state.zip(objectMessages).forEach { (actual, expected) ->
+      assertEquals(expected, actual as? io.ably.lib.objects.ObjectMessage)
+    }
+  }
+
+  @Test
+  fun testObjectMessageJsonSerialization() = runTest {
+    val protocolMessage = ProtocolMessage()
+    protocolMessage.action = ProtocolMessage.Action.`object`
+    protocolMessage.state = objectMessages
+
+    // Serialize the ProtocolMessage containing ObjectMessages to MsgPack format
+    val serializedProtoMsg = ProtocolSerializer.writeJSON(protocolMessage).toString(Charsets.UTF_8)
+    assertNotNull(serializedProtoMsg)
+
+    // Deserialize back to ProtocolMessage
+    val deserializedProtoMsg = ProtocolSerializer.fromJSON(serializedProtoMsg)
+    assertNotNull(deserializedProtoMsg)
+
+    deserializedProtoMsg.state.zip(objectMessages).forEach { (actual, expected) ->
+      assertEquals(expected, (actual as? io.ably.lib.objects.ObjectMessage))
+    }
+  }
+
+  @Test
+  fun testOmitNullInSerialization() = runTest {
+    val nullableObject = object {
+      val name = "Test Object"
+      val description: String? = null // This will be omitted if using Gson with excludeNulls
+      val value = 42
+    }
+    val serializedJsonString = gson.toJson(nullableObject)
+    // check serializedObject does not contain the null field
+    assertEquals("""{"name":"Test Object","value":42}""", serializedJsonString)
+
+    val serializedMsgpackBytes = msgpackMapper.writeValueAsBytes(nullableObject)
+    // check serializedObject does not contain the null field
+    assertEquals("""{"name":"Test Object","value":42}""", Serialisation.msgpackToGson(serializedMsgpackBytes).toString())
+  }
+}

live-objects/src/test/kotlin/io/ably/lib/objects/unit/ObjectMessageSizeTest.kt

@@ -11,12 +11,14 @@ import io.ably.lib.objects.ensureMessageSizeWithinLimit
 import io.ably.lib.objects.size
 import io.ably.lib.transport.Defaults
 import io.ably.lib.types.AblyException
+import io.ktor.utils.io.core.*
 import io.mockk.every
 import io.mockk.mockk
 import kotlinx.coroutines.test.runTest
 import org.junit.Test
 import kotlin.test.assertEquals
 import kotlin.test.assertFailsWith
+import kotlin.text.toByteArray
 
 class ObjectMessageSizeTest {
 
@@ -79,7 +81,7 @@ class ObjectMessageSizeTest {
         ), // Total ObjectCounter size: 8 bytes
 
         nonce = "nonce123", // Not counted in operation size
-        initialValue = "some-value", // Not counted in operation size
+        initialValue = Binary("some-value".toByteArray()), // Not counted in operation size
       ), // Total ObjectOperation size: 12 + 8 + 26 + 8 = 54 bytes
 
       objectState = ObjectState(