Add MessageAdapter for Kotlin Serialization (#92)

Author: alibagherifam

build.gradle.kts

@@ -21,6 +21,7 @@ buildscript {
         classpath("org.jetbrains.dokka:dokka-gradle-plugin:${versions.dokkaGradlePlugin}")
         classpath("io.gitlab.arturbosch.detekt" +
             ":detekt-gradle-plugin:${versions.detekt}")
+        classpath(kotlin("serialization", version = versions.kotlin))
     }
 }
 

buildSrc/src/main/kotlin/deps.kt

@@ -10,6 +10,7 @@ object versions {
     const val jfrogBuildInfoExtractor = "4.23.4"
     const val navigation = "2.1.0-rc01"
     const val coroutines = "1.3.2"
+    const val serialization = "1.3.3"
     const val broadcast = "1.0.0"
     const val lifecycle = "2.4.1"
     const val room = "2.2.5"
@@ -104,6 +105,8 @@ object deps {
                 "org.jetbrains.kotlinx:kotlinx-coroutines-android:${versions.coroutines}"
             const val test = "org.jetbrains.kotlinx:kotlinx-coroutines-test:${versions.coroutines}"
         }
+
+        const val serializationJson = "org.jetbrains.kotlinx:kotlinx-serialization-json:${versions.serialization}"
     }
 
     object logger {

courier-message-adapter-kotlin-serialization/.gitignore

@@ -0,0 +1 @@
+/build

courier-message-adapter-kotlin-serialization/api/courier-message-adapter-kotlin-serialization.api

@@ -0,0 +1,7 @@
+public final class com/gojek/courier/messageadapter/kotlinserialization/KotlinSerializationMessageAdapterFactory : com/gojek/courier/MessageAdapter$Factory {
+	public fun <init> ()V
+	public fun <init> (Lkotlinx/serialization/json/Json;)V
+	public synthetic fun <init> (Lkotlinx/serialization/json/Json;ILkotlin/jvm/internal/DefaultConstructorMarker;)V
+	public fun create (Ljava/lang/reflect/Type;[Ljava/lang/annotation/Annotation;)Lcom/gojek/courier/MessageAdapter;
+}
+

courier-message-adapter-kotlin-serialization/build.gradle.kts

@@ -0,0 +1,30 @@
+import plugin.KotlinLibraryConfigurationPlugin
+
+apply<KotlinLibraryConfigurationPlugin>()
+apply("$rootDir/gradle/script-ext.gradle")
+
+val version = ext.get("gitVersionName")
+
+ext {
+    set("PUBLISH_GROUP_ID", "com.gojek.courier")
+    set("PUBLISH_ARTIFACT_ID", "courier-message-adapter-kotlin-serialization")
+    set("PUBLISH_VERSION", ext.get("gitVersionName"))
+    set("minimumCoverage", "0.0")
+}
+
+plugins {
+    id("java-library")
+    kotlin("jvm")
+    kotlin("plugin.serialization")
+    id(ScriptPlugins.apiValidator) version versions.apiValidator
+}
+
+dependencies {
+    api(project(":courier-core"))
+    api(deps.kotlin.serializationJson)
+    implementation(deps.kotlin.stdlib.core)
+
+    testImplementation(deps.android.test.kotlinTestJunit)
+}
+
+apply(from = "${rootProject.projectDir}/gradle/publish-module.gradle")

courier-message-adapter-kotlin-serialization/src/main/java/com/gojek/courier/messageadapter/kotlinserialization/KotlinSerializationMessageAdapter.kt

@@ -0,0 +1,43 @@
+package com.gojek.courier.messageadapter.kotlinserialization
+
+import com.gojek.courier.Message
+import com.gojek.courier.MessageAdapter
+import java.lang.reflect.Type
+import kotlinx.serialization.ExperimentalSerializationApi
+import kotlinx.serialization.KSerializer
+import kotlinx.serialization.json.Json
+import kotlinx.serialization.serializer
+
+/**
+ * A [message adapter][MessageAdapter] that uses Kotlin Serialization.
+ */
+private class KotlinSerializationMessageAdapter<T>(
+    private val json: Json,
+    private val serializer: KSerializer<T>
+) : MessageAdapter<T> {
+
+    override fun fromMessage(topic: String, message: Message): T {
+        val stringValue = when (message) {
+            is Message.Bytes -> String(message.value, Charsets.UTF_8)
+        }
+        return json.decodeFromString(serializer, stringValue)
+    }
+
+    override fun toMessage(topic: String, data: T): Message =
+        json.encodeToString(serializer, data)
+            .toByteArray(Charsets.UTF_8)
+            .let(Message::Bytes)
+
+    override fun contentType() = "application/json"
+}
+
+@OptIn(ExperimentalSerializationApi::class)
+class KotlinSerializationMessageAdapterFactory(
+    private val json: Json = Json.Default
+) : MessageAdapter.Factory {
+
+    override fun create(type: Type, annotations: Array<Annotation>): MessageAdapter<*> {
+        val serializer = json.serializersModule.serializer(type)
+        return KotlinSerializationMessageAdapter(json, serializer)
+    }
+}

courier-message-adapter-kotlin-serialization/src/test/java/com/gojek/courier/messageadapter/kotlinserialization/KotlinSerializationMessageAdapterTest.kt

@@ -0,0 +1,46 @@
+package com.gojek.courier.messageadapter.kotlinserialization
+
+import com.gojek.courier.Message
+import com.gojek.courier.MessageAdapter
+import kotlinx.serialization.Serializable
+import org.junit.Assert.assertEquals
+import org.junit.Test
+
+class KotlinSerializationMessageAdapterTest {
+    private val messageAdapter = KotlinSerializationMessageAdapterFactory().create(
+        type = TestClass::class.java,
+        annotations = emptyArray()
+    ) as MessageAdapter<TestClass>
+
+    @Test
+    fun `test toMessage`() {
+        val testClass = TestClass(100, "test100")
+        val testString = """{"id":100,"name":"test100"}"""
+
+        val message = messageAdapter.toMessage(
+            topic = "any",
+            data = testClass
+        )
+
+        assertEquals(testString, String((message as Message.Bytes).value))
+    }
+
+    @Test
+    fun `test fromMessage`() {
+        val testClass = TestClass(100, "test100")
+        val testString = """{"id":100,"name":"test100"}"""
+
+        val message = messageAdapter.fromMessage(
+            topic = "any",
+            message = Message.Bytes(testString.toByteArray())
+        )
+
+        assertEquals(testClass, message)
+    }
+}
+
+@Serializable
+data class TestClass(
+    val id: Int,
+    val name: String
+)

docs/docs/MessageStreamAdapters.md

@@ -8,11 +8,13 @@ To serialize and deserialize received and published messages, Courier uses Messa
 
 Courier library provides the following message adapters:
 
-- courier-message-adapter-gson
+- [Gson](https://github.com/google/gson): courier-message-adapter-gson
 
-- courier-message-adapter-moshi
+- [Kotlin Serialization](https://github.com/Kotlin/kotlinx.serialization): courier-message-adapter-kotlin-serialization
 
-- courier-message-adapter-protobuf
+- [Moshi](https://github.com/square/moshi/): courier-message-adapter-moshi
+
+- [Protobuf](https://developers.google.com/protocol-buffers/): courier-message-adapter-protobuf
 
 You can also create your own custom message adapter by implementing the MessageAdapter.Factory interface.
 

settings.gradle

@@ -7,6 +7,7 @@ include ':courier-core'
 include ':courier-core-android'
 include ':courier-message-adapter-text'
 include ':courier-message-adapter-gson'
+include ':courier-message-adapter-kotlin-serialization'
 include ':courier-message-adapter-moshi'
 include ':courier-message-adapter-protobuf'
 include ':courier-stream-adapter-rxjava'