Fix plugin compatibility with Kotlin Gradle Plugin 1.9.0 release (#715) (#721)

Kotlin Gradle Plugin 1.9.0 release has changed how kapt tasks are configured: https://youtrack.jetbrains.com/issue/KT-54468/KAPT-Gradle-plugin-causes-eager-task-creation. Because of this change, generated proto sources are not passed to kaptGenerateStubs task leading to compilation error even in default setup.

If the Kotlin plugin version is 1.7.20 - protobuf plugin now, instead of directly configuring KotlinCompile task inputs, configures related KotlinSourceSet. This way additional sources are passed both for KotlinCompile and KaptGenerateStubs tasks.

Fixes issue #714

Co-authored-by: Yahor Berdnikau <[email protected]>

Author: YifeiZhuang

src/main/groovy/com/google/protobuf/gradle/ProtobufPlugin.groovy

@@ -57,6 +57,7 @@ import org.gradle.api.provider.Provider
 import org.gradle.api.tasks.SourceSet
 import org.gradle.language.jvm.tasks.ProcessResources
 import org.gradle.util.GradleVersion
+import org.jetbrains.kotlin.gradle.dsl.KotlinAndroidProjectExtension
 import org.jetbrains.kotlin.gradle.tasks.KotlinCompile
 
 /**
@@ -347,11 +348,19 @@ class ProtobufPlugin implements Plugin<Project> {
         variant.registerJavaGeneratingTask(generateProtoTask.get(), generateProtoTask.get().outputSourceDirectories)
 
         project.plugins.withId("org.jetbrains.kotlin.android") {
-          project.afterEvaluate {
-            String compileKotlinTaskName = Utils.getKotlinAndroidCompileTaskName(project, variant.name)
-            project.tasks.named(compileKotlinTaskName, KotlinCompile) { KotlinCompile task ->
-              task.dependsOn(generateProtoTask)
-              task.source(generateProtoTask.get().outputSourceDirectories)
+          // Checking if Kotlin plugin is a recent one - 1.7.20+
+          if (it.respondsTo("getPluginVersion")) {
+            KotlinAndroidProjectExtension kotlinExtension = project.extensions.getByType(KotlinAndroidProjectExtension)
+            kotlinExtension.target.compilations.named(variant.name) {
+              it.defaultSourceSet.kotlin.srcDirs(variantSourceSet.output)
+            }
+          } else {
+            project.afterEvaluate {
+              String compileKotlinTaskName = Utils.getKotlinAndroidCompileTaskName(project, variant.name)
+              project.tasks.named(compileKotlinTaskName, KotlinCompile) { KotlinCompile task ->
+                task.dependsOn(generateProtoTask)
+                task.source(generateProtoTask.get().outputSourceDirectories)
+              }
             }
           }
         }

src/test/groovy/com/google/protobuf/gradle/ProtobufAndroidPluginKotlinTest.groovy

@@ -8,9 +8,9 @@ import spock.lang.Unroll
 
 @CompileDynamic
 class ProtobufAndroidPluginKotlinTest extends Specification {
-  private static final List<String> GRADLE_VERSION = ["5.6", "6.5.1", "7.4.2", "7.6"]
-  private static final List<String> ANDROID_PLUGIN_VERSION = ["3.5.0", "4.1.0", "7.2.1", "7.3.1"]
-  private static final List<String> KOTLIN_VERSION = ["1.3.20", "1.3.20", "1.3.40", "1.7.20"]
+  private static final List<String> GRADLE_VERSION = ["5.6", "6.5.1", "7.4.2", "7.6.2", "7.6.2"]
+  private static final List<String> ANDROID_PLUGIN_VERSION = ["3.5.0", "4.1.0", "7.2.1", "7.3.1", "7.4.2"]
+  private static final List<String> KOTLIN_VERSION = ["1.3.20", "1.3.20", "1.3.40", "1.7.20", "1.9.0"]
 
   /**
    * This test may take a significant amount of Gradle daemon Metaspace memory in some