Update to Kotlin 2.1.0

build.gradle.kts

@@ -49,7 +49,6 @@ plugins {
   alias(libs.plugins.mavenPublish) apply false
   alias(libs.plugins.dokka)
   alias(libs.plugins.ksp) apply false
-  alias(libs.plugins.versionsPlugin)
   alias(libs.plugins.dependencyGuard) apply false
   alias(libs.plugins.compose) apply false
   alias(libs.plugins.kotlin.plugin.compose) apply false
@@ -169,15 +168,21 @@ subprojects {
   }
 
   val hasCompose = !project.hasProperty("circuit.noCompose")
+  val useK2Kapt =
+    providers.gradleProperty("kapt.use.k2").map { it.toBooleanStrict() }.getOrElse(false)
   plugins.withType<KotlinBasePlugin> {
     tasks.withType<KotlinCompilationTask<*>>().configureEach {
-      // Don't double apply to stub gen
       if (this is KaptGenerateStubsTask) {
-        // TODO due to Anvil we need to force language version 1.9
-        compilerOptions {
-          progressiveMode.set(false)
-          languageVersion.set(KotlinVersion.KOTLIN_1_9)
+        if (useK2Kapt) {
+          // K2 Kapt is in alpha
+          compilerOptions.allWarningsAsErrors.set(false)
+        } else {
+          compilerOptions {
+            progressiveMode.set(false)
+            languageVersion.set(KotlinVersion.KOTLIN_1_9)
+          }
         }
+        // Don't double apply to stub gen
         return@configureEach
       }
       val isWasmTask = name.contains("wasm", ignoreCase = true)
@@ -256,10 +261,6 @@ subprojects {
     module("com.google.guava:listenablefuture") { replacedBy("com.google.guava:guava") }
   }
 
-  pluginManager.withPlugin("org.jetbrains.kotlin.kapt") {
-    tasks.withType<KaptGenerateStubsTask>().configureEach { useK2Kapt.set(true) }
-  }
-
   pluginManager.withPlugin("com.vanniktech.maven.publish") {
     apply(plugin = "org.jetbrains.dokka")
 

circuit-foundation/api/android/circuit-foundation.api

@@ -92,7 +92,6 @@ public final class com/slack/circuit/foundation/CircuitKt {
 
 public final class com/slack/circuit/foundation/ComposableSingletons$CircuitKt {
 	public static final field INSTANCE Lcom/slack/circuit/foundation/ComposableSingletons$CircuitKt;
-	public static field lambda-1 Lkotlin/jvm/functions/Function4;
 	public fun <init> ()V
 	public final fun getLambda-1$circuit_foundation_release ()Lkotlin/jvm/functions/Function4;
 }

circuit-foundation/api/jvm/circuit-foundation.api

@@ -92,7 +92,6 @@ public final class com/slack/circuit/foundation/CircuitKt {
 
 public final class com/slack/circuit/foundation/ComposableSingletons$CircuitKt {
 	public static final field INSTANCE Lcom/slack/circuit/foundation/ComposableSingletons$CircuitKt;
-	public static field lambda-1 Lkotlin/jvm/functions/Function4;
 	public fun <init> ()V
 	public final fun getLambda-1$circuit_foundation ()Lkotlin/jvm/functions/Function4;
 }

circuit-overlay/api/android/circuit-overlay.api

@@ -9,7 +9,6 @@ public abstract class com/slack/circuit/overlay/AnimatedOverlay : com/slack/circ
 
 public final class com/slack/circuit/overlay/ComposableSingletons$ContentWithOverlaysKt {
 	public static final field INSTANCE Lcom/slack/circuit/overlay/ComposableSingletons$ContentWithOverlaysKt;
-	public static field lambda-1 Lkotlin/jvm/functions/Function4;
 	public fun <init> ()V
 	public final fun getLambda-1$circuit_overlay_release ()Lkotlin/jvm/functions/Function4;
 }

circuit-overlay/api/jvm/circuit-overlay.api

@@ -9,7 +9,6 @@ public abstract class com/slack/circuit/overlay/AnimatedOverlay : com/slack/circ
 
 public final class com/slack/circuit/overlay/ComposableSingletons$ContentWithOverlaysKt {
 	public static final field INSTANCE Lcom/slack/circuit/overlay/ComposableSingletons$ContentWithOverlaysKt;
-	public static field lambda-1 Lkotlin/jvm/functions/Function4;
 	public fun <init> ()V
 	public final fun getLambda-1$circuit_overlay ()Lkotlin/jvm/functions/Function4;
 }

circuitx/overlays/api/android/overlays.api

@@ -28,7 +28,6 @@ public final class com/slack/circuitx/overlays/BottomSheetOverlay : com/slack/ci
 
 public final class com/slack/circuitx/overlays/ComposableSingletons$BottomSheetOverlayKt {
 	public static final field INSTANCE Lcom/slack/circuitx/overlays/ComposableSingletons$BottomSheetOverlayKt;
-	public static field lambda-1 Lkotlin/jvm/functions/Function2;
 	public fun <init> ()V
 	public final fun getLambda-1$overlays_release ()Lkotlin/jvm/functions/Function2;
 }

circuitx/overlays/api/jvm/overlays.api

@@ -28,7 +28,6 @@ public final class com/slack/circuitx/overlays/BottomSheetOverlay : com/slack/ci
 
 public final class com/slack/circuitx/overlays/ComposableSingletons$BottomSheetOverlayKt {
 	public static final field INSTANCE Lcom/slack/circuitx/overlays/ComposableSingletons$BottomSheetOverlayKt;
-	public static field lambda-1 Lkotlin/jvm/functions/Function2;
 	public fun <init> ()V
 	public final fun getLambda-1$overlays ()Lkotlin/jvm/functions/Function2;
 }

gradle.properties

@@ -30,16 +30,14 @@ android.suppressUnsupportedOptionWarnings=android.suppressUnsupportedOptionWarni
   android.lint.useK2Uast
 
 android.lint.useK2Uast=true
-# TODO blocked on https://github.com/google/ksp/issues/2091
-ksp.useKSP2=false
+ksp.useKSP2=true
 
 # SKIE sets max versions, so we leave this in (even if commented out) for ease of use with new
 # Kotlin versions
-skie.kgpVersion=2.0.20
+#skie.kgpVersion=2.1.0
 
 # Use Kapt4 in K2
-# TODO doesn't work with Anvil yet
-kapt.use.k2=false
+kapt.use.k2=true
 
 org.gradle.parallel=true
 org.gradle.configureondemand=true
@@ -52,7 +50,6 @@ dependency.analysis.compatibility=NONE
 # Disable noisy stability warning
 kotlin.mpp.stability.nowarn=true
 kotlin.mpp.androidSourceSetLayoutVersion=2
-kotlin.mpp.androidGradlePluginCompatibility.nowarn=true
 # Ignore disabled targets (i.e iOS on Linux)
 kotlin.native.ignoreDisabledTargets=true
 kotlin.apple.xcodeCompatibility.nowarn=true

gradle/libs.versions.toml

@@ -28,13 +28,13 @@ jdk = "22"
 jvmTarget = "11"
 publishedJvmTarget = "1.8"
 kct = "0.7.0"
-kotlin = "2.0.21"
+kotlin = "2.1.0"
 kotlinInject = "0.7.2"
 kotlinInject-anvil = "0.1.1"
 kotlinpoet = "2.0.0"
 kotlinx-coroutines = "1.9.0"
 kotlinx-serialization = "1.7.3"
-ksp = "2.0.21-1.0.28"
+ksp = "2.1.0-1.0.29"
 ktfmt = "0.53"
 ktor = "3.0.3"
 leakcanary = "2.14"
@@ -49,12 +49,11 @@ picnic = "0.7.0"
 robolectric = "4.14.1"
 roborazzi = "1.37.0"
 skie = "0.10.0"
-spotless = "7.0.0.BETA2"
+spotless = "7.0.0.BETA4"
 sqldelight = "2.0.2"
 telephoto = "0.14.0"
 testParameterInjector = "1.18"
 turbine = "1.2.0"
-versionsPlugin = "0.49.0"
 
 [plugins]
 agp-application = { id = "com.android.application", version.ref = "agp" }
@@ -83,7 +82,6 @@ roborazzi = { id = "io.github.takahirom.roborazzi", version.ref = "roborazzi" }
 skie = { id = "co.touchlab.skie", version.ref = "skie" }
 spotless = { id = "com.diffplug.spotless", version.ref = "spotless" }
 sqldelight = { id = "app.cash.sqldelight", version.ref = "sqldelight" }
-versionsPlugin = { id = "com.github.ben-manes.versions", version.ref = "versionsPlugin" }
 
 [libraries]
 agp = { module = "com.android.tools.build:gradle", version.ref = "agp" }

samples/counter/gradle.properties

@@ -1,2 +1,2 @@
 # https://kotlinlang.org/docs/native-ios-integration.html#calling-kotlin-suspending-functions
-kotlin.native.binary.objcExportSuspendFunctionLaunchThreadRestriction=none
+kotlin.native.binary.objcExportSuspendFunctionLaunchThreadRestriction=none

samples/kotlin-inject/build.gradle.kts

@@ -1,5 +1,7 @@
 // Copyright (C) 2024 Slack Technologies, LLC
 // SPDX-License-Identifier: Apache-2.0
+import com.google.devtools.ksp.KspExperimental
+
 plugins {
   alias(libs.plugins.kotlin.jvm)
   alias(libs.plugins.ksp)
@@ -9,6 +11,10 @@ plugins {
 ksp {
   arg("circuit.codegen.lenient", "true")
   arg("circuit.codegen.mode", "kotlin_inject_anvil")
+  @OptIn(KspExperimental::class)
+  // kotlin-inject cannot see through typealiases in KSP2
+  // https://github.com/evant/kotlin-inject/issues/458
+  useKsp2.set(false)
 }
 
 dependencies {

samples/star/build.gradle.kts

@@ -2,7 +2,6 @@
 // SPDX-License-Identifier: Apache-2.0
 import com.android.build.api.dsl.LibraryExtension
 import com.google.devtools.ksp.gradle.KspAATask
-import com.google.devtools.ksp.gradle.KspTaskJvm
 import java.util.Locale
 import org.jetbrains.kotlin.gradle.ExperimentalKotlinGradlePluginApi
 import org.jetbrains.kotlin.gradle.dsl.JvmTarget
@@ -283,15 +282,8 @@ afterEvaluate {
     if (target != "Android" && target != "Jvm") continue
     val buildType = if (target == "Android") "Release" else ""
     val kspTaskName = "ksp${buildType}Kotlin${target}"
-    val useKSP2 = providers.gradleProperty("ksp.useKSP2").getOrElse("false").toBoolean()
     val generatedKspKotlinFiles =
-      if (useKSP2) {
-        val kspReleaseTask = tasks.named<KspAATask>(kspTaskName)
-        kspReleaseTask.flatMap { it.kspConfig.kotlinOutputDir }
-      } else {
-        val kspReleaseTask = tasks.named<KspTaskJvm>(kspTaskName)
-        kspReleaseTask.flatMap { it.destination }
-      }
+      tasks.named<KspAATask>(kspTaskName).flatMap { it.kspConfig.kotlinOutputDir }
     tasks.named<KotlinCompile>("kaptGenerateStubs${buildType}Kotlin${target}").configure {
       source(generatedKspKotlinFiles)
     }