[Gradle, JS] Detect classpath changes in KotlinJsDce

Now -Xdev-mode-overwriting-strategy=older compiler argument is handled on Gradle side to detect incremental changes to increase performance
#KT-35640 Fixed

libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/tasks/KotlinJsDce.kt

@@ -16,8 +16,16 @@
 
 package org.jetbrains.kotlin.gradle.tasks
 
+import org.gradle.api.file.FileCollection
 import org.gradle.api.file.FileTree
-import org.gradle.api.tasks.*
+import org.gradle.api.tasks.CacheableTask
+import org.gradle.api.tasks.Input
+import org.gradle.api.tasks.Internal
+import org.gradle.api.tasks.TaskAction
+import org.gradle.work.ChangeType
+import org.gradle.work.Incremental
+import org.gradle.work.InputChanges
+import org.jetbrains.kotlin.cli.common.arguments.DevModeOverwritingStrategies
 import org.jetbrains.kotlin.cli.common.arguments.K2JSDceArguments
 import org.jetbrains.kotlin.cli.js.dce.K2JSDce
 import org.jetbrains.kotlin.compilerRunner.runToolInSeparateProcess
@@ -65,21 +73,52 @@ abstract class KotlinJsDce : AbstractKotlinCompileTool<K2JSDceArguments>(), Kotl
     @Input
     var jvmArgs = mutableListOf<String>()
 
+    @Incremental
+    override fun getClasspath(): FileCollection {
+        return super.getClasspath()
+    }
+
     private val buildDir by lazy {
         project.buildDir
     }
 
+    private val isDevMode
+        get() = dceOptions.devMode || "-dev-mode" in dceOptions.freeCompilerArgs
+
+    private val isExplicitDevModeAllStrategy
+        get() = strategyAllArg in dceOptions.freeCompilerArgs ||
+                strategyOlderArg !in dceOptions.freeCompilerArgs &&
+                System.getProperty("kotlin.js.dce.devmode.overwriting.strategy") == DevModeOverwritingStrategies.ALL
+
     @TaskAction
-    fun performDce() {
-        val inputFiles = (listOf(source) + classpath
+    fun performDce(inputChanges: InputChanges) {
+        // in case of explicit `all` strategy do not perform incremental copy
+        val shouldPerformIncrementalCopy = isDevMode && !isExplicitDevModeAllStrategy
+
+        val classpathFiles = if (shouldPerformIncrementalCopy) {
+            inputChanges.getFileChanges(classpath)
+                .filter { it.changeType == ChangeType.MODIFIED || it.changeType == ChangeType.ADDED }
+                .map { it.file }
+        } else {
+            classpath
+        }
+        val inputFiles = (listOf(source) + classpathFiles
             .filter { !kotlinFilesOnly || isDceCandidate(it) }
             .map { objects.fileCollection().from(it).asFileTree })
             .reduce(FileTree::plus)
             .files.map { it.path }
 
-        val outputDirArgs = arrayOf("-output-dir", destinationDir.path)
+        val outputDirArgs = arrayOf("-output-dir", destinationDirectory.get().asFile.path)
 
-        val argsArray = serializedCompilerArguments.toTypedArray()
+        val processedSerializedArgs = if (shouldPerformIncrementalCopy) {
+            var shouldAddStrategyAllArgument = true
+            val processedArgs = serializedCompilerArguments
+                .map { if (it == strategyOlderArg) strategyAllArg.also { shouldAddStrategyAllArgument = false } else it }
+            if (shouldAddStrategyAllArgument) processedArgs + strategyAllArg else processedArgs
+        } else {
+            serializedCompilerArguments
+        }
+        val argsArray = processedSerializedArgs.toTypedArray()
 
         val log = GradleKotlinLogger(logger)
         val allArgs = argsArray + outputDirArgs + inputFiles
@@ -93,7 +132,6 @@ abstract class KotlinJsDce : AbstractKotlinCompileTool<K2JSDceArguments>(), Kotl
             jvmArgs
         )
         throwGradleExceptionIfError(exitCode)
-
     }
 
     private fun isDceCandidate(file: File): Boolean {
@@ -107,4 +145,9 @@ abstract class KotlinJsDce : AbstractKotlinCompileTool<K2JSDceArguments>(), Kotl
 
         return File("${file.canonicalPathWithoutExtension()}.meta.js").exists()
     }
+
+    companion object {
+        const val strategyAllArg = "-Xdev-mode-overwriting-strategy=${DevModeOverwritingStrategies.ALL}"
+        const val strategyOlderArg = "-Xdev-mode-overwriting-strategy=${DevModeOverwritingStrategies.OLDER}"
+    }
 }