Feature: Support Kotlin coding conventions

gradle/libs.versions.toml

@@ -24,6 +24,8 @@ buildConfigPlugin = "5.7.1"
 
 kotlinPoet = "2.2.0"
 
+textCaseConverter = "2.0.0"
+
 # Misc (Testing, Example Apps)
 protobufJvm = "3.25.6"
 protobufGradlePlugin = "0.9.5"
@@ -65,6 +67,8 @@ ktor-core = { module = "io.ktor:ktor-client-core", version.ref = "ktor" }
 squareup-kotlinpoet = { group = "com.squareup", name = "kotlinpoet", version.ref = "kotlinPoet" }
 squareup-okio = { module = "com.squareup.okio:okio", version.ref = "okio" }
 
+text-case-converter = { group = "dev.turingcomplete", name = "text-case-converter", version.ref = "textCaseConverter" }
+
 kotlin-gradle-plugin = { group = "org.jetbrains.kotlin", name = "kotlin-gradle-plugin", version.ref = "kotlin" }
 android-gradle-plugin = { group = "com.android.tools.build", name = "gradle", version.ref = "androidGradlePlugin" }
 

kmp-grpc-internal-test/build.gradle.kts

@@ -1,3 +1,4 @@
+import io.github.timortel.kmpgrpc.plugin.NamingStrategy
 import org.gradle.api.tasks.testing.logging.TestExceptionFormat
 import org.gradle.api.tasks.testing.logging.TestLogEvent
 

kmp-grpc-internal-test/src/commonTest/kotlin/io/github/timortel/kotlin_multiplatform_grpc_plugin/test/defaults.kt

@@ -30,7 +30,7 @@ fun createMessageWithAllTypes() = messageWithEverything {
     field4 = 25L
     field5 = 3f
     field6 = 7.0
-    field7 = SimpleEnum.ONE
+    field7 = SimpleEnum.One
     field8 = simpleMessage { field1 = "Foo" }
 
     field9List += listOf("Foo", "Bar", "Baz")
@@ -39,11 +39,11 @@ fun createMessageWithAllTypes() = messageWithEverything {
     field12List += listOf(12L, 23424L, 10312313L, -123131L)
     field13List += listOf(-1f, 2f, 2.5f, -0.5f)
     field14List += listOf(-0.5, 15.0)
-    field15List += listOf(SimpleEnum.ZERO, SimpleEnum.ZERO, SimpleEnum.ONE, SimpleEnum.TWO)
+    field15List += listOf(SimpleEnum.Zero, SimpleEnum.Zero, SimpleEnum.One, SimpleEnum.Two)
 
     field16Map += mapOf("foo" to 1, "bar" to -13, "baz" to 112)
     field17Map += mapOf(1 to simpleMessage { field1 = "Foo" }, 13 to simpleMessage { field1 = "Baz" })
-    field18Map += mapOf(-15 to SimpleEnum.ONE, 23 to SimpleEnum.TWO)
+    field18Map += mapOf(-15 to SimpleEnum.One, 23 to SimpleEnum.Two)
 
     field19 = 12u
     field20 = 14uL
@@ -74,16 +74,16 @@ fun createMessageWithAllExtensions() = ExtensionsTest.MessageWithEveryExtension(
         set(ExtensionsTest.field4, 25L)
         set(ExtensionsTest.field5, 3f)
         set(ExtensionsTest.field6, 7.0)
-        set(ExtensionsTest.field7, SimpleEnum.ONE)
+        set(ExtensionsTest.field7, SimpleEnum.One)
         set(ExtensionsTest.field8, simpleMessage { field1 = "Foo" })
 
-        set(ExtensionsTest.field9, listOf("Foo", "Bar", "Baz"))
-        set(ExtensionsTest.field10, listOf(true, false, true, true))
-        set(ExtensionsTest.field11, listOf(1, 2, 3, 4, -12, 1341))
-        set(ExtensionsTest.field12, listOf(12L, 23424L, 10312313L, -123131L))
-        set(ExtensionsTest.field13, listOf(-1f, 2f, 2.5f, -0.5f))
-        set(ExtensionsTest.field14, listOf(-0.5, 15.0))
-        set(ExtensionsTest.field15, listOf(SimpleEnum.ZERO, SimpleEnum.ZERO, SimpleEnum.ONE, SimpleEnum.TWO))
+        set(ExtensionsTest.field9List, listOf("Foo", "Bar", "Baz"))
+        set(ExtensionsTest.field10List, listOf(true, false, true, true))
+        set(ExtensionsTest.field11List, listOf(1, 2, 3, 4, -12, 1341))
+        set(ExtensionsTest.field12List, listOf(12L, 23424L, 10312313L, -123131L))
+        set(ExtensionsTest.field13List, listOf(-1f, 2f, 2.5f, -0.5f))
+        set(ExtensionsTest.field14List, listOf(-0.5, 15.0))
+        set(ExtensionsTest.field15List, listOf(SimpleEnum.Zero, SimpleEnum.Zero, SimpleEnum.One, SimpleEnum.Two))
 
         set(ExtensionsTest.field19, 12u)
         set(ExtensionsTest.field20, 14uL)
@@ -95,16 +95,16 @@ fun createMessageWithAllExtensions() = ExtensionsTest.MessageWithEveryExtension(
         set(ExtensionsTest.field26, -1353532131L)
         set(ExtensionsTest.field27, byteArrayOf(0, -13, 127))
 
-        set(ExtensionsTest.field28, listOf(0u, 134u, 35311u))
-        set(ExtensionsTest.field29, listOf(0uL, 134uL, 353111345134uL))
-        set(ExtensionsTest.field30, listOf(-134, -145129, 34521431))
-        set(ExtensionsTest.field31, listOf(-1L, 141341413413L, -134134314131L))
-        set(ExtensionsTest.field32, listOf(0u, 14234u, 1413413413u))
-        set(ExtensionsTest.field33, listOf(0uL, 134uL, 353111345134uL))
-        set(ExtensionsTest.field34, listOf(-14, 0, 1241522))
-        set(ExtensionsTest.field35, listOf(-154L, 0L, 4514124121L))
+        set(ExtensionsTest.field28List, listOf(0u, 134u, 35311u))
+        set(ExtensionsTest.field29List, listOf(0uL, 134uL, 353111345134uL))
+        set(ExtensionsTest.field30List, listOf(-134, -145129, 34521431))
+        set(ExtensionsTest.field31List, listOf(-1L, 141341413413L, -134134314131L))
+        set(ExtensionsTest.field32List, listOf(0u, 14234u, 1413413413u))
+        set(ExtensionsTest.field33List, listOf(0uL, 134uL, 353111345134uL))
+        set(ExtensionsTest.field34List, listOf(-14, 0, 1241522))
+        set(ExtensionsTest.field35List, listOf(-154L, 0L, 4514124121L))
         set(
-            ExtensionsTest.field36, listOf(
+            ExtensionsTest.field36List, listOf(
                 byteArrayOf(0, -127, 127),
                 byteArrayOf(-123, 1, 2),
                 byteArrayOf(3, 3, -6)

kmp-grpc-internal-test/src/commonTest/kotlin/io/github/timortel/kotlin_multiplatform_grpc_plugin/test/model/DSLBuilderTest.kt

@@ -117,7 +117,7 @@ class DSLBuilderTest {
 
     @Test
     fun testCreateEnumMessage() {
-        val enum = SimpleEnum.ONE
+        val enum = SimpleEnum.One
 
         val msg = messageWithEnum {
             field1 = enum
@@ -128,7 +128,7 @@ class DSLBuilderTest {
 
     @Test
     fun testCreateRepeatedEnumMessage() {
-        val list = listOf(SimpleEnum.ONE, SimpleEnum.TWO, SimpleEnum.ZERO, SimpleEnum.ONE)
+        val list = listOf(SimpleEnum.One, SimpleEnum.Two, SimpleEnum.Zero, SimpleEnum.One)
 
         val msg = messageWithRepeatedEnum {
             field1List += list
@@ -191,11 +191,11 @@ class DSLBuilderTest {
     @Test
     fun testCreateMessageWithEnumMap() {
         val map = mapOf(
-            33 to SimpleEnum.ONE,
-            12 to SimpleEnum.TWO,
-            13 to SimpleEnum.TWO,
-            -12 to SimpleEnum.ONE,
-            5 to SimpleEnum.ZERO
+            33 to SimpleEnum.One,
+            12 to SimpleEnum.Two,
+            13 to SimpleEnum.Two,
+            -12 to SimpleEnum.One,
+            5 to SimpleEnum.Zero
         )
 
         val msg = messageWithEnumMap {

kmp-grpc-internal-test/src/commonTest/kotlin/io/github/timortel/kotlin_multiplatform_grpc_plugin/test/serialization/OpenClosedEnumMapFieldSerializationTest.kt

@@ -15,8 +15,8 @@ class OpenClosedEnumMapFieldSerializationTest {
                 2 to 1
             ),
             expectedValues = mapOf(
-                1 to ClosedEnumTest.ClosedEnum.DEFAULT,
-                2 to ClosedEnumTest.ClosedEnum.ONE,
+                1 to ClosedEnumTest.ClosedEnum.Default,
+                2 to ClosedEnumTest.ClosedEnum.One,
             ),
             expectedUnknownFieldCount = 0
         )
@@ -28,7 +28,7 @@ class OpenClosedEnumMapFieldSerializationTest {
                 3 to 2
             ),
             expectedValues = mapOf(
-                2 to ClosedEnumTest.ClosedEnum.ONE
+                2 to ClosedEnumTest.ClosedEnum.One
             ),
             expectedUnknownFieldCount = 2
         )
@@ -57,8 +57,8 @@ class OpenClosedEnumMapFieldSerializationTest {
                 2 to 1
             ),
             expectedValues = mapOf(
-                1 to OpenEnumTest.OpenEnum.DEFAULT,
-                2 to OpenEnumTest.OpenEnum.ONE,
+                1 to OpenEnumTest.OpenEnum.Default,
+                2 to OpenEnumTest.OpenEnum.One,
             ),
             expectedUnknownFieldCount = 0
         )
@@ -71,7 +71,7 @@ class OpenClosedEnumMapFieldSerializationTest {
             ),
             expectedValues = mapOf(
                 1 to OpenEnumTest.OpenEnum.Unrecognized(-1),
-                2 to OpenEnumTest.OpenEnum.ONE,
+                2 to OpenEnumTest.OpenEnum.One,
                 3 to OpenEnumTest.OpenEnum.Unrecognized(2)
             ),
             expectedUnknownFieldCount = 0

kmp-grpc-internal-test/src/commonTest/kotlin/io/github/timortel/kotlin_multiplatform_grpc_plugin/test/serialization/OpenClosedEnumOneOfSerializationTest.kt

@@ -13,14 +13,14 @@ class OpenClosedEnumOneOfSerializationTest {
         runClosedOneOfDeserializationTest(
             UnknownField.Varint(1, 0),
             ClosedEnumTest.MessageWithClosedOneOf.A.B(
-                ClosedEnumTest.ClosedEnum.DEFAULT
+                ClosedEnumTest.ClosedEnum.Default
             ),
             emptyList()
         )
         runClosedOneOfDeserializationTest(
             UnknownField.Varint(1, 1),
             ClosedEnumTest.MessageWithClosedOneOf.A.B(
-                ClosedEnumTest.ClosedEnum.ONE
+                ClosedEnumTest.ClosedEnum.One
             ),
             emptyList()
         )
@@ -49,14 +49,14 @@ class OpenClosedEnumOneOfSerializationTest {
         runOpenOneOfDeserializationTest(
             UnknownField.Varint(1, 0),
             OpenEnumTest.MessageWithOpenOneOf.A.B(
-                OpenEnumTest.OpenEnum.DEFAULT
+                OpenEnumTest.OpenEnum.Default
             ),
             emptyList()
         )
         runOpenOneOfDeserializationTest(
             UnknownField.Varint(1, 1),
             OpenEnumTest.MessageWithOpenOneOf.A.B(
-                OpenEnumTest.OpenEnum.ONE
+                OpenEnumTest.OpenEnum.One
             ),
             emptyList()
         )

kmp-grpc-internal-test/src/commonTest/kotlin/io/github/timortel/kotlin_multiplatform_grpc_plugin/test/serialization/OpenClosedEnumRepeatedFieldSerializationTest.kt

@@ -13,24 +13,24 @@ class OpenClosedEnumRepeatedFieldSerializationTest {
     fun testClosedRepeatedDeserializationScenarios() {
         runClosedRepeatedDeserializationTest(
             fields = listOf(0),
-            expectedValues = listOf(ClosedEnumTest.ClosedEnum.DEFAULT),
+            expectedValues = listOf(ClosedEnumTest.ClosedEnum.Default),
             expectedUnknownFields = emptyList()
         )
 
         runClosedRepeatedDeserializationTest(
             fields = listOf(0, 1, 0),
             expectedValues = listOf(
-                ClosedEnumTest.ClosedEnum.DEFAULT,
-                ClosedEnumTest.ClosedEnum.ONE,
-                ClosedEnumTest.ClosedEnum.DEFAULT
+                ClosedEnumTest.ClosedEnum.Default,
+                ClosedEnumTest.ClosedEnum.One,
+                ClosedEnumTest.ClosedEnum.Default
             ),
             expectedUnknownFields = emptyList()
         )
 
         runClosedRepeatedDeserializationTest(
             fields = listOf(-4, 3, 1),
             expectedValues = listOf(
-                ClosedEnumTest.ClosedEnum.ONE
+                ClosedEnumTest.ClosedEnum.One
             ),
             expectedUnknownFields = listOf(
                 UnknownField.Varint(1, -4),
@@ -68,16 +68,16 @@ class OpenClosedEnumRepeatedFieldSerializationTest {
     fun testOpenRepeatedDeserializationScenarios() {
         runOpenRepeatedDeserializationTest(
             fields = listOf(0),
-            expectedValues = listOf(OpenEnumTest.OpenEnum.DEFAULT),
+            expectedValues = listOf(OpenEnumTest.OpenEnum.Default),
             expectedUnknownFields = emptyList()
         )
 
         runOpenRepeatedDeserializationTest(
             fields = listOf(0, 1, 0),
             expectedValues = listOf(
-                OpenEnumTest.OpenEnum.DEFAULT,
-                OpenEnumTest.OpenEnum.ONE,
-                OpenEnumTest.OpenEnum.DEFAULT
+                OpenEnumTest.OpenEnum.Default,
+                OpenEnumTest.OpenEnum.One,
+                OpenEnumTest.OpenEnum.Default
             ),
             expectedUnknownFields = emptyList()
         )
@@ -87,7 +87,7 @@ class OpenClosedEnumRepeatedFieldSerializationTest {
             expectedValues = listOf(
                 OpenEnumTest.OpenEnum.Unrecognized(-4),
                 OpenEnumTest.OpenEnum.Unrecognized(3),
-                OpenEnumTest.OpenEnum.ONE,
+                OpenEnumTest.OpenEnum.One,
             ),
             expectedUnknownFields = emptyList()
         )

kmp-grpc-internal-test/src/commonTest/kotlin/io/github/timortel/kotlin_multiplatform_grpc_plugin/test/serialization/OpenClosedEnumScalarFieldSerializationTest.kt

@@ -10,11 +10,11 @@ class OpenClosedEnumScalarFieldSerializationTest {
 
     @Test
     fun testClosedScalarDeserializationScenarios() {
-        runClosedScalarDeserializationTest(UnknownField.Varint(1, 0), ClosedEnumTest.ClosedEnum.DEFAULT, emptyList())
-        runClosedScalarDeserializationTest(UnknownField.Varint(1, 1), ClosedEnumTest.ClosedEnum.ONE, emptyList())
+        runClosedScalarDeserializationTest(UnknownField.Varint(1, 0), ClosedEnumTest.ClosedEnum.Default, emptyList())
+        runClosedScalarDeserializationTest(UnknownField.Varint(1, 1), ClosedEnumTest.ClosedEnum.One, emptyList())
         runClosedScalarDeserializationTest(
             UnknownField.Varint(1, 2),
-            ClosedEnumTest.ClosedEnum.DEFAULT,
+            ClosedEnumTest.ClosedEnum.Default,
             listOf(UnknownField.Varint(1, 2))
         )
     }
@@ -34,8 +34,8 @@ class OpenClosedEnumScalarFieldSerializationTest {
 
     @Test
     fun testOpenScalarDeserializationScenarios() {
-        runOpenScalarDeserializationTest(UnknownField.Varint(1, 0), OpenEnumTest.OpenEnum.DEFAULT, emptyList())
-        runOpenScalarDeserializationTest(UnknownField.Varint(1, 1), OpenEnumTest.OpenEnum.ONE, emptyList())
+        runOpenScalarDeserializationTest(UnknownField.Varint(1, 0), OpenEnumTest.OpenEnum.Default, emptyList())
+        runOpenScalarDeserializationTest(UnknownField.Varint(1, 1), OpenEnumTest.OpenEnum.One, emptyList())
         runOpenScalarDeserializationTest(
             UnknownField.Varint(1, 2),
             OpenEnumTest.OpenEnum.Unrecognized(2),

kmp-grpc-internal-test/src/jvmMacOsTest/kotlin/DefaultCertificatesRpcTest.kt

@@ -24,14 +24,14 @@ abstract class DefaultCertificatesRpcTest : ServerTest {
         val stub = HelloServiceStub(channelWithCertificate)
 
         val msg = HelloRequest(greeting = "Hello World")
-        stub.SayHello(msg)
+        stub.sayHello(msg)
     }
 
     @Test
     fun testConnectionFailsWithoutCertificates() = runTest {
         val stub = HelloServiceStub(channelWithoutCertificates)
 
         val msg = HelloRequest(greeting = "Hello World")
-        assertFailsWith<StatusException> { stub.SayHello(msg) }
+        assertFailsWith<StatusException> { stub.sayHello(msg) }
     }
 }

kmp-grpc-plugin/build.gradle.kts

@@ -70,6 +70,8 @@ dependencies {
     implementation(libs.squareup.kotlinpoet)
     compileOnly(libs.kotlin.gradle.plugin)
 
+    implementation(libs.text.case.converter)
+
     testImplementation(platform(libs.junit.bom))
     testImplementation(libs.junit.jupiter)
     testRuntimeOnly(libs.junit.platform.launcher)

kmp-grpc-plugin/src/main/java/io/github/timortel/kmpgrpc/plugin/GenerateKmpGrpcSourcesTask.kt

@@ -3,6 +3,7 @@ package io.github.timortel.kmpgrpc.plugin
 import io.github.timortel.kmpgrpc.plugin.sourcegeneration.ProtoSourceGenerator
 import io.github.timortel.kmpgrpc.plugin.sourcegeneration.SystemInputFile
 import org.gradle.api.DefaultTask
+import org.gradle.api.GradleException
 import org.gradle.api.Project
 import org.gradle.api.file.ConfigurableFileCollection
 import org.gradle.api.file.DirectoryProperty
@@ -46,6 +47,9 @@ abstract class GenerateKmpGrpcSourcesTask : DefaultTask() {
     @get:Input
     abstract val skipWellKnownExtensions: Property<Boolean>
 
+    @get:Input
+    abstract val namingStrategy: Property<NamingStrategy>
+
     @get:InputDirectory
     abstract val generatedSourcesOutputFolder: DirectoryProperty
 
@@ -81,6 +85,13 @@ abstract class GenerateKmpGrpcSourcesTask : DefaultTask() {
 
     @TaskAction
     fun generateSources() {
+        if (namingStrategy.get() != NamingStrategy.KOTLIN_IDIOMATIC && includeWellKnownTypes.get()) {
+            throw GradleException(
+                "Invalid Configuration: 'includeWellKnownTypes' can only be set to true " +
+                        "if 'namingStrategy' is set to KOTLIN_IDIOMATIC."
+            )
+        }
+
         val tsm = targetSourcesMap.get()
 
         val shouldGenerateTargetMap = KmpGrpcExtension.targets.associateWith { target ->
@@ -100,6 +111,7 @@ abstract class GenerateKmpGrpcSourcesTask : DefaultTask() {
             logger = logger,
             protoFolders = protoFolders,
             shouldGenerateTargetMap = shouldGenerateTargetMap,
+            namingStrategy = namingStrategy.get(),
             commonOutputFolder = getCommonOutputFolder(outputFolder),
             jvmOutputFolder = getJVMOutputFolder(outputFolder),
             jsOutputFolder = getJSOutputFolder(outputFolder),
@@ -108,7 +120,6 @@ abstract class GenerateKmpGrpcSourcesTask : DefaultTask() {
             internalVisibility = internalVisibility.get()
         )
 
-
         if (includeWellKnownTypes.get() && skipWellKnownExtensions.get()) {
             copyWellKnownExtensions()
         }

kmp-grpc-plugin/src/main/java/io/github/timortel/kmpgrpc/plugin/KmpGrpcExtension.kt

@@ -31,6 +31,8 @@ open class KmpGrpcExtension @Inject constructor(objects: ObjectFactory) {
 
     /**
      * Instructs the plugin to download and include the well known proto-types: https://protobuf.dev/reference/protobuf/google.protobuf/
+     *
+     * Can only be used in combination with `namingStrategy` `KOTLIN_IDIOMATIC`.
      */
     val includeWellKnownTypes: Property<Boolean> = objects
         .property(Boolean::class.java)
@@ -43,6 +45,24 @@ open class KmpGrpcExtension @Inject constructor(objects: ObjectFactory) {
         .property(Boolean::class.java)
         .convention(false)
 
+    /**
+     * Configures how Protobuf messages and fields are mapped to Kotlin identifiers.
+     *
+     * This property allows you to choose between standard Protobuf naming, idiomatic
+     * Kotlin style, or the legacy behavior. It affects the generated class names,
+     * property names, and method names.
+     *
+     * Supported strategies:
+     * - [NamingStrategy.KOTLIN_IDIOMATIC]: (Default) Transforms names to Kotlin conventions
+     * (e.g., `user_id` -> `userId`, `User_Message` -> `UserMessage`).
+     * - [NamingStrategy.PROTO_LITERAL]: Preserves the exact names defined in the .proto file.
+     * - [NamingStrategy.LEGACY]: Preserves .proto names but appends "List" or "Map"
+     * suffixes to collection types (Behavior from v1.x).
+     */
+    val namingStrategy: Property<NamingStrategy> = objects
+        .property(NamingStrategy::class.java)
+        .convention(NamingStrategy.KOTLIN_IDIOMATIC)
+
     fun common(targets: List<String> = listOf("commonMain")) {
         targetSourcesMap.put(COMMON, targets)
     }