Constraint Kotlin language version for the Gradle plugin

Author: Goooler

tools/gradle-plugin/build.gradle.kts

@@ -1,6 +1,10 @@
 import java.nio.file.Paths
 import java.util.Properties
 import kotlin.io.path.exists
+import org.gradle.api.plugins.JavaPlugin.API_ELEMENTS_CONFIGURATION_NAME
+import org.jetbrains.kotlin.gradle.dsl.JvmDefaultMode
+import org.jetbrains.kotlin.gradle.dsl.JvmTarget
+import org.jetbrains.kotlin.gradle.dsl.KotlinVersion
 
 plugins {
     alias(libs.plugins.kotlin.jvm)
@@ -15,6 +19,20 @@ tasks.validatePlugins {
     enableStricterValidation = true
 }
 
+val jdkRelease = "17"
+
+kotlin {
+    compilerOptions {
+        allWarningsAsErrors = true
+        // https://docs.gradle.org/current/userguide/compatibility.html#kotlin
+        apiVersion = KotlinVersion.KOTLIN_2_2
+        languageVersion = apiVersion
+        jvmTarget = JvmTarget.fromTarget(jdkRelease)
+        jvmDefault = JvmDefaultMode.NO_COMPATIBILITY
+        freeCompilerArgs.add("-Xjdk-release=$jdkRelease")
+    }
+}
+
 gradlePlugin {
     vcsUrl = "https://github.com/ComposeGears/Valkyrie"
     website = "https://github.com/ComposeGears/Valkyrie"
@@ -30,6 +48,14 @@ gradlePlugin {
     }
 }
 
+configurations.named(API_ELEMENTS_CONFIGURATION_NAME) {
+    attributes.attribute(
+        // TODO: https://github.com/gradle/gradle/issues/24608
+        GradlePluginApiVersion.GRADLE_PLUGIN_API_VERSION_ATTRIBUTE,
+        objects.named("9.0.0"),
+    )
+}
+
 val sharedTestResourcesDir: File =
     project(projects.components.test.path)
         .layout
@@ -63,6 +89,10 @@ tasks.pluginUnderTestMetadata {
     pluginClasspath.from(testPluginClasspath)
 }
 
+tasks.withType<JavaCompile>().configureEach {
+    options.release = jdkRelease.toInt()
+}
+
 dependencies {
     compileOnly(libs.agp.api)
     compileOnly(libs.kotlin.gradle.plugin)