[Gradle, JS] Fix destination dir for link tasks

- Add test on empty output with empty inputs

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/kotlin/org/jetbrains/kotlin/gradle/Kotlin2JsGradlePluginIT.kt

@@ -29,6 +29,44 @@ class Kotlin2JsIrGradlePluginIT : AbstractKotlin2JsGradlePluginIT(true) {
             assert(dts.readText().contains("function bar(): string"))
         }
     }
+
+    @Test
+    fun testCleanOutputWithEmptySources() {
+        with(Project("kotlin-js-nodejs-project", GradleVersionRequired.AtLeast("5.2"))) {
+            setupWorkingDir()
+            gradleBuildScript().modify(::transformBuildScriptWithPluginsDsl)
+            gradleSettingsScript().modify(::transformBuildScriptWithPluginsDsl)
+
+            build(
+                "build",
+                options = defaultBuildOptions().copy(jsCompilerType = JsCompilerType.ir)
+            ) {
+                assertSuccessful()
+
+                assertTasksExecuted(":compileProductionKotlinJs")
+
+                assertFileExists("build/js/packages/kotlin-js-nodejs/kotlin/kotlin-js-nodejs.js")
+            }
+
+            File("${projectDir.canonicalPath}/src").deleteRecursively()
+
+            gradleBuildScript().appendText(
+                """${"\n"}
+                tasks {
+                    compileProductionKotlinJs {
+                        type = org.jetbrains.kotlin.gradle.targets.js.ir.KotlinJsIrType.DEVELOPMENT
+                    }
+                }
+            """.trimIndent()
+            )
+
+            build("build") {
+                assertSuccessful()
+
+                assertNoSuchFile("build/js/packages/kotlin-js-nodejs/kotlin/")
+            }
+        }
+    }
 }
 
 class Kotlin2JsGradlePluginIT : AbstractKotlin2JsGradlePluginIT(false) {
@@ -547,4 +585,6 @@ abstract class AbstractKotlin2JsGradlePluginIT(private val irBackend: Boolean) :
             assertFileExists("app/build/distributions/index.html")
         }
     }
+
+
 }

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/resources/testProject/kotlin-js-nodejs-project/build.gradle.kts

@@ -0,0 +1,21 @@
+plugins {
+    kotlin("js").version("<pluginMarkerVersion>")
+}
+
+dependencies {
+    implementation(kotlin("stdlib-js"))
+}
+
+repositories {
+    mavenLocal()
+    jcenter()
+}
+
+kotlin {
+    target {
+        useCommonJs()
+        produceExecutable()
+        nodejs {
+        }
+    }
+}

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/resources/testProject/kotlin-js-nodejs-project/settings.gradle.kts

@@ -0,0 +1,8 @@
+pluginManagement {
+    repositories {
+        mavenLocal()
+        gradlePluginPortal()
+    }
+}
+
+rootProject.name = "kotlin-js-nodejs"

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/resources/testProject/kotlin-js-nodejs-project/src/main/kotlin/Base.kt

@@ -0,0 +1,14 @@
+/*
+ * Copyright 2010-2019 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
+ */
+
+package com.example
+
+fun best(): Int {
+    return 42
+}
+
+fun simpleBest(): Int {
+    return 73
+}

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

@@ -41,6 +41,7 @@ import org.jetbrains.kotlin.gradle.scripting.internal.ScriptingGradleSubplugin
 import org.jetbrains.kotlin.gradle.targets.js.ir.KotlinJsIrCompilation
 import org.jetbrains.kotlin.gradle.targets.js.ir.KotlinJsIrLink
 import org.jetbrains.kotlin.gradle.targets.js.ir.KotlinJsIrType
+import org.jetbrains.kotlin.gradle.targets.js.npm.npmProject
 import org.jetbrains.kotlin.gradle.targets.jvm.KotlinJvmTarget
 import org.jetbrains.kotlin.gradle.tasks.*
 import org.jetbrains.kotlin.gradle.tasks.KotlinCompile
@@ -106,11 +107,14 @@ internal abstract class KotlinSourceSetProcessor<T : AbstractKotlinCompile<*>>(
             kotlinCompilation.output.addClassesDir { project.files(task.map { it.destinationDir }) }
         }
 
-    protected fun registerKotlinCompileTask(name: String = kotlinCompilation.compileKotlinTaskName): TaskProvider<out T> {
+    protected fun registerKotlinCompileTask(
+        name: String = kotlinCompilation.compileKotlinTaskName,
+        compileDestinationDir: File = defaultKotlinDestinationDir
+    ): TaskProvider<out T> {
         logger.kotlinDebug("Creating kotlin compile task $name")
 
         KotlinCompileTaskData.register(name, kotlinCompilation).apply {
-            destinationDir.set(project.provider { defaultKotlinDestinationDir })
+            destinationDir.set(project.provider { compileDestinationDir })
         }
 
         return doRegisterTask(project, name) {
@@ -374,7 +378,8 @@ internal class KotlinJsIrSourceSetProcessor(
             compilation.developmentLinkTaskName
         ).onEach { taskName ->
             registerKotlinCompileTask(
-                taskName
+                taskName,
+                compilation.npmProject.dist
             )
         }.forEach { taskName ->
             project.tasks.named(taskName).configure {

libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/targets/js/npm/NpmProject.kt

@@ -52,8 +52,11 @@ open class NpmProject(val compilation: KotlinJsCompilation) {
     val packageJsonTask: KotlinPackageJsonTask
         get() = project.tasks.getByName(packageJsonTaskName) as KotlinPackageJsonTask
 
+    val dist: File
+        get() = dir.resolve(DIST_FOLDER)
+
     val main: String
-        get() = "kotlin/$name.js"
+        get() = "$DIST_FOLDER/$name.js"
 
     val externalsDirRoot: File
         get() = project.buildDir.resolve("externals").resolve(name)
@@ -115,5 +118,6 @@ open class NpmProject(val compilation: KotlinJsCompilation) {
     companion object {
         const val PACKAGE_JSON = "package.json"
         const val NODE_MODULES = "node_modules"
+        const val DIST_FOLDER = "kotlin"
     }
 }