Fix regression related to no class found in AGP 8.7 and below

(cherry picked from commit 6975c18)

Author: hfmehmed

gradle-plugin/src/main/kotlin/com/google/devtools/ksp/gradle/KspConfigurations.kt

@@ -1,12 +1,12 @@
 package com.google.devtools.ksp.gradle
 
-import com.android.build.api.dsl.KotlinMultiplatformAndroidLibraryTarget
 import com.google.devtools.ksp.gradle.AndroidPluginIntegration.useLegacyVariantApi
 import org.gradle.api.InvalidUserCodeException
 import org.gradle.api.Project
 import org.gradle.api.artifacts.Configuration
 import org.jetbrains.kotlin.gradle.dsl.*
 import org.jetbrains.kotlin.gradle.plugin.*
+import org.jetbrains.kotlin.gradle.plugin.mpp.KotlinAndroidTarget
 import org.jetbrains.kotlin.gradle.plugin.mpp.KotlinCommonCompilation
 import org.jetbrains.kotlin.gradle.plugin.mpp.KotlinJvmAndroidCompilation
 
@@ -148,9 +148,7 @@ class KspConfigurations(private val project: Project) {
      * and things get worse when you add product flavors. So, we use AGP sets as the source of truth.
      */
     private fun decorateKotlinTarget(target: KotlinTarget, isKotlinMultiplatform: Boolean) {
-        if (target.platformType == KotlinPlatformType.androidJvm &&
-            target !is KotlinMultiplatformAndroidLibraryTarget
-        ) {
+        if (isPlainAndroidTarget(target) || isOldKmpAndroidTarget(target)) {
             if (project.useLegacyVariantApi() || isKotlinMultiplatform) {
                 createAndroidSourceSetConfigurations(target.project, target)
             }
@@ -166,6 +164,24 @@ class KspConfigurations(private val project: Project) {
         }
     }
 
+    // check if this target is the old implementation of android kmp target (using com.android.library)
+    // org.jetbrains.kotlin.gradle.plugin.mpp.KotlinAndroidTarget
+    private fun isOldKmpAndroidTarget(target: KotlinTarget): Boolean {
+        val isKotlinAndroidTargetClass = try {
+            target is KotlinAndroidTarget
+        } catch (e: Throwable) {
+            false
+        }
+        return target.platformType == KotlinPlatformType.androidJvm &&
+            isMppProject() && isKotlinAndroidTargetClass
+    }
+
+    private fun isPlainAndroidTarget(target: KotlinTarget): Boolean {
+        return target.platformType == KotlinPlatformType.androidJvm && !isMppProject()
+    }
+
+    private fun isMppProject() = project.pluginManager.hasPlugin("kotlin-multiplatform")
+
     /**
      * Returns the user-facing configurations involved in the given compilation.
      * We use [KotlinCompilation.kotlinSourceSets], not [KotlinCompilation.allKotlinSourceSets] for a few reasons:
@@ -184,9 +200,8 @@ class KspConfigurations(private val project: Project) {
         compilation.kotlinSourceSets.mapTo(results) {
             getKotlinConfigurationName(compilation, it)
         }
-        if (compilation.platformType == KotlinPlatformType.androidJvm &&
-            compilation.target !is KotlinMultiplatformAndroidLibraryTarget
-        ) {
+
+        if (isPlainAndroidTarget(compilation.target) || isOldKmpAndroidTarget(compilation.target)) {
             compilation as KotlinJvmAndroidCompilation
             AndroidPluginIntegration.getCompilationSourceSets(compilation).mapTo(results) {
                 getAndroidConfigurationName(compilation.target, it)

integration-tests/build.gradle.kts

@@ -61,7 +61,7 @@ tasks.test {
     maxParallelForks = max(1, Runtime.getRuntime().availableProcessors() / 2)
 
     // Exclude test classes from agpCompatibilityTest
-    exclude(agpCompatibilityTestClasses)
+    // exclude(agpCompatibilityTestClasses)
 
     // Apply common settings
     configureCommonSettings()

integration-tests/src/test/kotlin/com/google/devtools/ksp/test/BuiltInKotlinAGP900IT.kt

@@ -17,7 +17,7 @@ class BuiltInKotlinAGP900IT {
     fun testRunsKSP() {
         val gradleRunner = GradleRunner.create().withProjectDir(project.root).withGradleVersion("9.0.0")
 
-        File(project.root, "gradle.properties").appendText("\nagpVersion=9.0.0-alpha03")
+        File(project.root, "gradle.properties").appendText("\nagpVersion=9.0.0-alpha12")
         gradleRunner.withArguments(":workload:compileDebugKotlin").build().let { result ->
             Assert.assertEquals(TaskOutcome.SUCCESS, result.task(":workload:kspDebugKotlin")?.outcome)
         }