[Gradle] IdeAdditionalArtifactResolver, IdeDependencyResolver: Replace object Empty with companion val empty

... to remove the type from the API surface.

KT-58601

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

@@ -1,10 +1,10 @@
 public abstract interface class org/jetbrains/kotlin/gradle/plugin/ide/IdeAdditionalArtifactResolver {
+	public static final field Companion Lorg/jetbrains/kotlin/gradle/plugin/ide/IdeAdditionalArtifactResolver$Companion;
 	public abstract fun resolve (Lorg/jetbrains/kotlin/gradle/plugin/KotlinSourceSet;Ljava/util/Set;)V
 }
 
-public final class org/jetbrains/kotlin/gradle/plugin/ide/IdeAdditionalArtifactResolver$Empty : org/jetbrains/kotlin/gradle/plugin/ide/IdeAdditionalArtifactResolver {
+public final class org/jetbrains/kotlin/gradle/plugin/ide/IdeAdditionalArtifactResolver$Companion {
-	public static final field INSTANCE Lorg/jetbrains/kotlin/gradle/plugin/ide/IdeAdditionalArtifactResolver$Empty;
+	public final fun getEmpty ()Lorg/jetbrains/kotlin/gradle/plugin/ide/IdeAdditionalArtifactResolver;
-	public fun resolve (Lorg/jetbrains/kotlin/gradle/plugin/KotlinSourceSet;Ljava/util/Set;)V
 }
 
 public abstract interface class org/jetbrains/kotlin/gradle/plugin/ide/IdeDependencyEffect {
@@ -25,17 +25,13 @@ public abstract interface class org/jetbrains/kotlin/gradle/plugin/ide/IdeDepend
 public final class org/jetbrains/kotlin/gradle/plugin/ide/IdeDependencyResolver$Companion {
 	public static final field DOCUMENTATION_BINARY_TYPE Ljava/lang/String;
 	public static final field SOURCES_BINARY_TYPE Ljava/lang/String;
+	public final fun getEmpty ()Lorg/jetbrains/kotlin/gradle/plugin/ide/IdeDependencyResolver;
 	public final fun getGradleArtifact (Lorg/jetbrains/kotlin/gradle/idea/tcs/IdeaKotlinDependency;)Lorg/gradle/api/artifacts/result/ResolvedArtifactResult;
 	public final fun getResolvedBy (Lorg/jetbrains/kotlin/gradle/idea/tcs/IdeaKotlinDependency;)Lorg/jetbrains/kotlin/gradle/plugin/ide/IdeDependencyResolver;
 	public final fun setGradleArtifact (Lorg/jetbrains/kotlin/gradle/idea/tcs/IdeaKotlinDependency;Lorg/gradle/api/artifacts/result/ResolvedArtifactResult;)V
 	public final fun setResolvedBy (Lorg/jetbrains/kotlin/gradle/idea/tcs/IdeaKotlinDependency;Lorg/jetbrains/kotlin/gradle/plugin/ide/IdeDependencyResolver;)V
 }
 
-public final class org/jetbrains/kotlin/gradle/plugin/ide/IdeDependencyResolver$Empty : org/jetbrains/kotlin/gradle/plugin/ide/IdeDependencyResolver {
-	public static final field INSTANCE Lorg/jetbrains/kotlin/gradle/plugin/ide/IdeDependencyResolver$Empty;
-	public fun resolve (Lorg/jetbrains/kotlin/gradle/plugin/KotlinSourceSet;)Ljava/util/Set;
-}
-
 public abstract interface class org/jetbrains/kotlin/gradle/plugin/ide/IdeDependencyResolver$WithBuildDependencies {
 	public abstract fun dependencies (Lorg/gradle/api/Project;)Ljava/lang/Iterable;
 }

libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/plugin/ide/IdeAdditionalArtifactResolver.kt

@@ -46,8 +46,11 @@ fun interface IdeAdditionalArtifactResolver {
     fun resolve(sourceSet: KotlinSourceSet, dependencies: Set<IdeaKotlinDependency>)
 
     @ExternalKotlinTargetApi
-    object Empty : IdeAdditionalArtifactResolver {
+    companion object {
-        override fun resolve(sourceSet: KotlinSourceSet, dependencies: Set<IdeaKotlinDependency>) = Unit
+        /**
+         * Empty [IdeAdditionalArtifactResolver] that will not resolve any artifact (noop)
+         */
+        val empty = IdeAdditionalArtifactResolver { _, _ -> }
     }
 }
 

libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/plugin/ide/IdeDependencyResolver.kt

@@ -53,13 +53,14 @@ fun interface IdeDependencyResolver {
         fun dependencies(project: Project): Iterable<Any>
     }
 
-    @ExternalKotlinTargetApi
-    object Empty : IdeDependencyResolver {
-        override fun resolve(sourceSet: KotlinSourceSet): Set<IdeaKotlinDependency> = emptySet()
-    }
-
     @ExternalKotlinTargetApi
     companion object {
+
+        /**
+         * [IdeDependencyResolver] that will just return an empty Set of dependencies (noop)
+         */
+        val empty = IdeDependencyResolver { emptySet() }
+
         /**
          * Special binaryType String that indicates that a certain dependency is only a sources.jar and
          * therefore should be attached as extra to the binary dependency.
@@ -98,10 +99,10 @@ fun interface IdeDependencyResolver {
  */
 @ExternalKotlinTargetApi
 fun IdeDependencyResolver(
-    resolvers: Iterable<IdeDependencyResolver?>
+    resolvers: Iterable<IdeDependencyResolver?>,
 ): IdeDependencyResolver {
     val resolversList = resolvers.filterNotNull()
-    if (resolversList.isEmpty()) return IdeDependencyResolver.Empty
+    if (resolversList.isEmpty()) return IdeDependencyResolver.empty
     return IdeCompositeDependencyResolver(resolversList)
 }
 
@@ -113,7 +114,7 @@ fun IdeDependencyResolver(
  */
 @ExternalKotlinTargetApi
 fun IdeDependencyResolver(
-    vararg resolvers: IdeDependencyResolver?
+    vararg resolvers: IdeDependencyResolver?,
 ): IdeDependencyResolver = IdeDependencyResolver(resolvers.toList())
 
 
@@ -138,7 +139,7 @@ operator fun IdeDependencyResolver.plus(other: IdeDependencyResolver): IdeDepend
 }
 
 private class IdeCompositeDependencyResolver(
-    val children: List<IdeDependencyResolver>
+    val children: List<IdeDependencyResolver>,
 ) : IdeDependencyResolver, IdeDependencyResolver.WithBuildDependencies {
     override fun resolve(sourceSet: KotlinSourceSet): Set<IdeaKotlinDependency> {
         return children.flatMap { child -> child.resolve(sourceSet) }.toSet()

libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/plugin/ide/IdeMultiplatformImportFactory.kt

@@ -164,21 +164,21 @@ internal fun IdeMultiplatformImport(extension: KotlinProjectExtension): IdeMulti
 
         /* Overwrite android dependencies by empty resolver */
         registerDependencyResolver(
-            resolver = IdeDependencyResolver.Empty,
+            resolver = IdeDependencyResolver.empty,
             constraint = SourceSetConstraint.isAndroid,
             phase = IdeMultiplatformImport.DependencyResolutionPhase.BinaryDependencyResolution,
             level = IdeMultiplatformImport.DependencyResolutionLevel.Overwrite
         )
 
         registerDependencyResolver(
-            resolver = IdeDependencyResolver.Empty,
+            resolver = IdeDependencyResolver.empty,
             constraint = SourceSetConstraint.isAndroid,
             phase = IdeMultiplatformImport.DependencyResolutionPhase.SourcesAndDocumentationResolution,
             level = IdeMultiplatformImport.DependencyResolutionLevel.Overwrite
         )
 
         registerAdditionalArtifactResolver(
-            resolver = IdeAdditionalArtifactResolver.Empty,
+            resolver = IdeAdditionalArtifactResolver.empty,
             constraint = SourceSetConstraint.isAndroid,
             phase = IdeMultiplatformImport.AdditionalArtifactResolutionPhase.SourcesAndDocumentationResolution,
             level = IdeMultiplatformImport.AdditionalArtifactResolutionLevel.Overwrite