[Gradle] Replace KotlinSourceSetTree interface with simpler class

^KT-58676 Verification Pending

libraries/tools/kotlin-gradle-plugin-api/api/kotlin-gradle-plugin-api.api

@@ -1094,9 +1094,13 @@ public abstract interface class org/jetbrains/kotlin/gradle/plugin/KotlinSourceS
 	public abstract fun getSourceSets ()Lorg/gradle/api/NamedDomainObjectContainer;
 }
 
-public abstract interface class org/jetbrains/kotlin/gradle/plugin/KotlinSourceSetTree {
+public final class org/jetbrains/kotlin/gradle/plugin/KotlinSourceSetTree {
 	public static final field Companion Lorg/jetbrains/kotlin/gradle/plugin/KotlinSourceSetTree$Companion;
-	public abstract fun getName ()Ljava/lang/String;
+	public fun <init> (Ljava/lang/String;)V
+	public fun equals (Ljava/lang/Object;)Z
+	public final fun getName ()Ljava/lang/String;
+	public fun hashCode ()I
+	public fun toString ()Ljava/lang/String;
 }
 
 public final class org/jetbrains/kotlin/gradle/plugin/KotlinSourceSetTree$Companion {
@@ -1107,10 +1111,6 @@ public final class org/jetbrains/kotlin/gradle/plugin/KotlinSourceSetTree$Compan
 	public final fun getUnitTest ()Lorg/jetbrains/kotlin/gradle/plugin/KotlinSourceSetTree;
 }
 
-public final class org/jetbrains/kotlin/gradle/plugin/KotlinSourceSetTreeKt {
-	public static final fun KotlinSourceSetTree (Ljava/lang/String;)Lorg/jetbrains/kotlin/gradle/plugin/KotlinSourceSetTree;
-}
-
 public abstract interface class org/jetbrains/kotlin/gradle/plugin/KotlinTarget : org/gradle/api/Named, org/gradle/api/attributes/HasAttributes, org/jetbrains/kotlin/gradle/plugin/HasProject, org/jetbrains/kotlin/tooling/core/HasMutableExtras {
 	public abstract fun attributes (Lkotlin/jvm/functions/Function1;)V
 	public abstract fun attributes (Lorg/gradle/api/Action;)V
@@ -1157,11 +1157,11 @@ public abstract interface class org/jetbrains/kotlin/gradle/plugin/KotlinTargetE
 public abstract interface class org/jetbrains/kotlin/gradle/plugin/KotlinTargetHierarchy {
 }
 
-public final class org/jetbrains/kotlin/gradle/plugin/KotlinTargetHierarchy$SourceSetTree : org/jetbrains/kotlin/gradle/plugin/KotlinSourceSetTree {
+public final class org/jetbrains/kotlin/gradle/plugin/KotlinTargetHierarchy$SourceSetTree {
 	public static final field Companion Lorg/jetbrains/kotlin/gradle/plugin/KotlinTargetHierarchy$SourceSetTree$Companion;
 	public fun <init> (Ljava/lang/String;)V
 	public fun equals (Ljava/lang/Object;)Z
-	public fun getName ()Ljava/lang/String;
+	public final fun getName ()Ljava/lang/String;
 	public fun hashCode ()I
 	public fun toString ()Ljava/lang/String;
 }

libraries/tools/kotlin-gradle-plugin-api/src/common/kotlin/org/jetbrains/kotlin/gradle/plugin/KotlinSourceSetTree.kt

@@ -5,12 +5,6 @@
 
 package org.jetbrains.kotlin.gradle.plugin
 
-import org.jetbrains.kotlin.gradle.plugin.KotlinSourceSetTree.Companion.instrumentedTest
-import org.jetbrains.kotlin.gradle.plugin.KotlinSourceSetTree.Companion.integrationTest
-import org.jetbrains.kotlin.gradle.plugin.KotlinSourceSetTree.Companion.main
-import org.jetbrains.kotlin.gradle.plugin.KotlinSourceSetTree.Companion.test
-import org.jetbrains.kotlin.gradle.plugin.KotlinSourceSetTree.Companion.unitTest
-
 /**
  * When applying any [KotlinHierarchyTemplate] (e.g. by calling `applyDefaultHierarchyTemplate()`), the descriptor will
  * be applied on individual compilations, creating multiple trees of shared SourceSets.
@@ -60,59 +54,8 @@ import org.jetbrains.kotlin.gradle.plugin.KotlinSourceSetTree.Companion.unitTest
  * There are some exceptions, where the name of the compilations cannot be chosen by the user directly (Android)
  * In this case, the name of the SourceSet can be configured outside the target hierarchy DSL.
  */
-sealed interface KotlinSourceSetTree {
-    val name: String
+class KotlinSourceSetTree(val name: String) {
 
-    companion object {
-        /**
-         * The 'main' SourceSetTree. Typically, with 'commonMain' as the root SourceSet
-         */
-        val main: KotlinSourceSetTree = KotlinSourceSetTreeImpl("main")
-
-        /**
-         * The 'test' SourceSetTree. Typically, with 'commonTest' as the root SourceSet
-         */
-        val test: KotlinSourceSetTree = KotlinSourceSetTreeImpl("test")
-
-        /**
-         * Special pre-defined SourceSetTree: Can be used to introduce a new tree with 'commonUnitTest' as the root SourceSet
-         * e.g. relevant for organising Android unitTest compilations/SourceSets
-         */
-        val unitTest: KotlinSourceSetTree = KotlinSourceSetTreeImpl("unitTest")
-
-
-        /**
-         * Special pre-defined SourceSetTree: Can be used to introduce a new tree with 'commonInstrumentedTest' as the root SourceSet
-         * e.g. relevant for organising Android instrumented compilations/SourceSets
-         */
-        val instrumentedTest: KotlinSourceSetTree = KotlinSourceSetTreeImpl("instrumentedTest")
-
-
-        /**
-         * Special pre-defined SourceSetTree: Can be used to introduce a new tree with 'commonIntegrationTest' as root SourceSEt
-         */
-        val integrationTest: KotlinSourceSetTree = KotlinSourceSetTreeImpl("integrationTest")
-
-    }
-}
-
-fun KotlinSourceSetTree(name: String): KotlinSourceSetTree {
-    return when (name) {
-        main.name -> main
-        test.name -> test
-        unitTest.name -> unitTest
-        instrumentedTest.name -> instrumentedTest
-        integrationTest.name -> integrationTest
-        else -> KotlinSourceSetTreeImpl(name)
-    }
-}
-
-/*
-Implementation
- */
-
-
-private class KotlinSourceSetTreeImpl(override val name: String) : KotlinSourceSetTree {
     override fun toString(): String = name
 
     override fun equals(other: Any?): Boolean {
@@ -123,4 +66,36 @@ private class KotlinSourceSetTreeImpl(override val name: String) : KotlinSourceS
     override fun hashCode(): Int {
         return name.hashCode()
     }
+
+    companion object {
+        /**
+         * The 'main' SourceSetTree. Typically, with 'commonMain' as the root SourceSet
+         */
+        val main: KotlinSourceSetTree = KotlinSourceSetTree("main")
+
+        /**
+         * The 'test' SourceSetTree. Typically, with 'commonTest' as the root SourceSet
+         */
+        val test: KotlinSourceSetTree = KotlinSourceSetTree("test")
+
+        /**
+         * Special pre-defined SourceSetTree: Can be used to introduce a new tree with 'commonUnitTest' as the root SourceSet
+         * e.g. relevant for organising Android unitTest compilations/SourceSets
+         */
+        val unitTest: KotlinSourceSetTree = KotlinSourceSetTree("unitTest")
+
+
+        /**
+         * Special pre-defined SourceSetTree: Can be used to introduce a new tree with 'commonInstrumentedTest' as the root SourceSet
+         * e.g. relevant for organising Android instrumented compilations/SourceSets
+         */
+        val instrumentedTest: KotlinSourceSetTree = KotlinSourceSetTree("instrumentedTest")
+
+
+        /**
+         * Special pre-defined SourceSetTree: Can be used to introduce a new tree with 'commonIntegrationTest' as root SourceSEt
+         */
+        val integrationTest: KotlinSourceSetTree = KotlinSourceSetTree("integrationTest")
+
+    }
 }

libraries/tools/kotlin-gradle-plugin-api/src/common/kotlin/org/jetbrains/kotlin/gradle/plugin/KotlinTargetHierarchy.kt

@@ -9,7 +9,7 @@ package org.jetbrains.kotlin.gradle.plugin
 interface KotlinTargetHierarchy {
 
     @Deprecated("Use KotlinSourceSetTree instead", replaceWith = ReplaceWith("KotlinSourceSetTree"))
-    class SourceSetTree(override val name: String) : KotlinSourceSetTree {
+    class SourceSetTree(val name: String)  {
         override fun toString(): String = name
 
         override fun equals(other: Any?): Boolean {

libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/plugin/hierarchy/KotlinSourceSetTreeClassifier.kt

@@ -106,7 +106,7 @@ internal suspend fun KotlinSourceSetTreeClassifier.classify(compilation: KotlinC
         is KotlinSourceSetTreeClassifier.Value -> tree
         is KotlinSourceSetTreeClassifier.Name -> KotlinSourceSetTree(name)
         is KotlinSourceSetTreeClassifier.None -> null
-        is SourceSetTreeClassifierWrapper -> classifier.classify(compilation)
+        is SourceSetTreeClassifierWrapper -> classifier.classify(compilation)?.name?.let(::KotlinSourceSetTree)
     }
 }
 

libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/plugin/mpp/targetHierarchy/SourceSetTreeClassifier.kt

@@ -41,13 +41,13 @@ sealed class SourceSetTreeClassifier {
 
 
     @ExternalKotlinTargetApi
-    class Property(val property: org.gradle.api.provider.Property<KotlinSourceSetTree>) : SourceSetTreeClassifier() {
+    class Property(val property: org.gradle.api.provider.Property<SourceSetTree>) : SourceSetTreeClassifier() {
         override fun toString(): String {
             return property.toString()
         }
     }
 
-    internal suspend fun classify(compilation: KotlinCompilation<*>): KotlinSourceSetTree? {
+    internal suspend fun classify(compilation: KotlinCompilation<*>): SourceSetTree? {
         return when (this) {
             is Default -> SourceSetTree(compilation.name)
             is Property -> property.awaitFinalValue()

libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/targets/android/KotlinAndroidTarget.kt

@@ -13,7 +13,6 @@ import org.gradle.api.attributes.Attribute
 import org.gradle.api.attributes.AttributeContainer
 import org.jetbrains.kotlin.gradle.ExperimentalKotlinGradlePluginApi
 import org.jetbrains.kotlin.gradle.plugin.*
-import org.jetbrains.kotlin.gradle.plugin.KotlinTargetHierarchy.SourceSetTree
 import org.jetbrains.kotlin.gradle.plugin.mpp.pm20.util.copyAttributes
 import org.jetbrains.kotlin.gradle.utils.dashSeparatedName
 import org.jetbrains.kotlin.gradle.utils.forAllAndroidVariants

libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/targets/android/KotlinAndroidTargetVariantDsl.kt

@@ -10,14 +10,13 @@ import org.gradle.api.model.ObjectFactory
 import org.gradle.api.provider.Property
 import org.jetbrains.kotlin.gradle.ExperimentalKotlinGradlePluginApi
 import org.jetbrains.kotlin.gradle.plugin.KotlinSourceSetTree
-import org.jetbrains.kotlin.gradle.plugin.KotlinTargetHierarchy.SourceSetTree
 import org.jetbrains.kotlin.gradle.utils.property
 
 
 @ExperimentalKotlinGradlePluginApi
 interface KotlinAndroidTargetVariantDsl {
     /**
-     * Configures under which [SourceSetTree] the currently configured Android Variant shall be placed.
+     * Configures under which [KotlinSourceSetTree] the currently configured Android Variant shall be placed.
      * e.g.
      *
      * ```kotlin