Add test for yarn setup by kotlinYarnSetup task

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

@@ -1,6 +1,7 @@
 package org.jetbrains.kotlin.gradle
 
 import org.gradle.api.logging.LogLevel
+import org.gradle.wrapper.GradleUserHomeLookup
 import org.jetbrains.kotlin.gradle.tasks.USING_JS_INCREMENTAL_COMPILATION_MESSAGE
 import org.jetbrains.kotlin.gradle.util.getFileByName
 import org.jetbrains.kotlin.gradle.util.getFilesByNames
@@ -413,4 +414,26 @@ class Kotlin2JsGradlePluginIT : BaseGradleIT() {
             assertFileExists("build/js/node_modules/puppeteer/.local-chromium")
         }
     }
+
+    @Test
+    fun testYarnSetup() = with(Project("yarn-setup", GradleVersionRequired.AtLeast("4.10.2"))) {
+        setupWorkingDir()
+        gradleBuildScript().modify(::transformBuildScriptWithPluginsDsl)
+        gradleSettingsScript().modify(::transformBuildScriptWithPluginsDsl)
+
+        GradleUserHomeLookup.gradleUserHome().resolve("yarn").deleteRecursively()
+
+        build("kotlinYarnSetup") {
+            assertSuccessful()
+
+            assertTasksExecuted(
+                ":kotlinYarnSetup"
+            )
+
+            assertFileExists(
+                path = GradleUserHomeLookup.gradleUserHome().resolve("yarn").canonicalPath,
+                inWorkingDir = false
+            )
+        }
+    }
 }

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/resources/testProject/yarn-setup/build.gradle.kts

@@ -0,0 +1,27 @@
+import org.jetbrains.kotlin.gradle.targets.js.yarn.yarn
+
+plugins {
+    kotlin("js") version "<pluginMarkerVersion>"
+}
+
+group = "com.example"
+version = "1.0"
+
+repositories {
+    mavenLocal()
+    jcenter()
+}
+
+yarn
+
+kotlin.sourceSets {
+    getByName("main") {
+        dependencies {
+            implementation(kotlin("stdlib-js"))
+        }
+    }
+}
+
+kotlin.target {
+    nodejs()
+}

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/resources/testProject/yarn-setup/gradle.properties

@@ -0,0 +1 @@
+kotlin.tests.individualTaskReports=true

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/resources/testProject/yarn-setup/settings.gradle.kts

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

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/resources/testProject/yarn-setup/src/main/kotlin/Main.kt

@@ -0,0 +1,10 @@
+/*
+ * 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 main() {
+    println("Hello, Yarn")
+}