[Gradle, JS] Backport possibility to disable granular workspaces

libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/targets/js/yarn/YarnRootExtension.kt

@@ -1,14 +1,17 @@
 /*
- * Copyright 2010-2019 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license
- * that can be found in the license/LICENSE.txt file.
+ * Copyright 2010-2020 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 org.jetbrains.kotlin.gradle.targets.js.yarn
 
+import org.gradle.api.Incubating
 import org.gradle.api.Project
+import org.gradle.api.tasks.TaskProvider
 import org.jetbrains.kotlin.gradle.internal.ConfigurationPhaseAware
 import org.jetbrains.kotlin.gradle.logging.kotlinInfo
 import org.jetbrains.kotlin.gradle.targets.js.nodejs.NodeJsRootPlugin
+import org.jetbrains.kotlin.gradle.targets.js.npm.tasks.RootPackageJsonTask
 import org.jetbrains.kotlin.gradle.tasks.internal.CleanableStore
 
 open class YarnRootExtension(val project: Project) : ConfigurationPhaseAware<YarnEnv>() {
@@ -33,6 +36,21 @@ open class YarnRootExtension(val project: Project) : ConfigurationPhaseAware<Yar
     val useWorkspaces: Boolean
         get() = !disableWorkspaces
 
+    val rootPackageJsonTaskProvider: TaskProvider<RootPackageJsonTask>
+        get() = project.tasks
+            .withType(RootPackageJsonTask::class.java)
+            .named(RootPackageJsonTask.NAME)
+
+    @Incubating
+    fun disableGranularWorkspaces() {
+        val packageJsonUmbrella = NodeJsRootPlugin.apply(project)
+            .packageJsonUmbrellaTaskProvider
+
+        rootPackageJsonTaskProvider.configure {
+            it.dependsOn(packageJsonUmbrella)
+        }
+    }
+
     override fun finalizeConfiguration(): YarnEnv {
         val cleanableStore = CleanableStore[installationDir.path]