Upgrade to Kotlin 2.1

Author: bclozel

buildSrc/build.gradle

@@ -22,7 +22,6 @@ dependencies {
 	checkstyle("io.spring.javaformat:spring-javaformat-checkstyle:${javaFormatVersion}")
 
 	implementation("org.jetbrains.kotlin:kotlin-gradle-plugin:${kotlinVersion}")
-	implementation("org.jetbrains.kotlin:kotlin-compiler-embeddable:${kotlinVersion}")
 	implementation("io.spring.javaformat:spring-javaformat-gradle-plugin:${javaFormatVersion}")
 	implementation "com.tngtech.archunit:archunit:1.4.0"
 }

buildSrc/src/main/java/org/springframework/graphql/build/conventions/KotlinConventions.java

@@ -16,11 +16,9 @@
 
 package org.springframework.graphql.build.conventions;
 
-import java.util.ArrayList;
-import java.util.List;
-
 import org.gradle.api.Project;
-import org.jetbrains.kotlin.gradle.dsl.KotlinJvmOptions;
+import org.jetbrains.kotlin.gradle.dsl.JvmTarget;
+import org.jetbrains.kotlin.gradle.dsl.KotlinVersion;
 import org.jetbrains.kotlin.gradle.tasks.KotlinCompile;
 
 /**
@@ -35,15 +33,19 @@ public void apply(Project project) {
 	}
 
 	private void configure(KotlinCompile compile) {
-		KotlinJvmOptions kotlinOptions = compile.getKotlinOptions();
-		kotlinOptions.setApiVersion("1.7");
-		kotlinOptions.setLanguageVersion("1.7");
-		kotlinOptions.setJvmTarget("17");
-		kotlinOptions.setJavaParameters(true);
-		kotlinOptions.setAllWarningsAsErrors(true);
-		List<String> freeCompilerArgs = new ArrayList<>(compile.getKotlinOptions().getFreeCompilerArgs());
-		freeCompilerArgs.addAll(List.of("-Xsuppress-version-warnings", "-Xjsr305=strict", "-opt-in=kotlin.RequiresOptIn"));
-		compile.getKotlinOptions().setFreeCompilerArgs(freeCompilerArgs);
+		compile.compilerOptions(options -> {
+			options.getApiVersion().set(KotlinVersion.KOTLIN_2_1);
+			options.getLanguageVersion().set(KotlinVersion.KOTLIN_2_1);
+			options.getJvmTarget().set(JvmTarget.JVM_17);
+			options.getJavaParameters().set(true);
+			options.getAllWarningsAsErrors().set(true);
+			options.getFreeCompilerArgs().addAll(
+					"-Xsuppress-version-warnings",
+					"-Xjsr305=strict", // For dependencies using JSR 305
+					"-opt-in=kotlin.RequiresOptIn",
+					"-Xjdk-release=17" // Needed due to https://youtrack.jetbrains.com/issue/KT-49746
+			);
+		});
 	}
 
 }

gradle.properties

@@ -5,6 +5,6 @@ org.gradle.daemon=true
 org.gradle.parallel=true
 org.gradle.jvmargs=-Dfile.encoding=UTF-8
 
-kotlinVersion=1.9.25
+kotlinVersion=2.1.20
 
 kotlin.stdlib.default.dependency=false

platform/build.gradle

@@ -17,7 +17,7 @@ dependencies {
 	api(platform("com.querydsl:querydsl-bom:5.1.0"))
 	api(platform("io.rsocket:rsocket-bom:1.1.5"))
 	api(platform("org.jetbrains.kotlin:kotlin-bom:${kotlinVersion}"))
-	api(platform("org.jetbrains.kotlinx:kotlinx-coroutines-bom:1.8.1"))
+	api(platform("org.jetbrains.kotlinx:kotlinx-coroutines-bom:1.10.1"))
 	api(platform("org.junit:junit-bom:5.12.2"))
 	api(platform("org.mockito:mockito-bom:5.16.0"))
 	api(platform("org.testcontainers:testcontainers-bom:1.20.6"))