[Gradle, JS] Add test on success installation of duplicated dependencies

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

@@ -444,4 +444,14 @@ class Kotlin2JsGradlePluginIT : BaseGradleIT() {
             )
         }
     }
+
+    @Test
+    fun testNpmDependenciesClash() = with(Project("npm-dependencies-clash", GradleVersionRequired.AtLeast("4.10.2"))) {
+        setupWorkingDir()
+        gradleBuildScript().modify(::transformBuildScriptWithPluginsDsl)
+
+        build("test") {
+            assertSuccessful()
+        }
+    }
 }

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/resources/testProject/npm-dependencies-clash/build.gradle.kts

@@ -0,0 +1,31 @@
+plugins {
+    kotlin("js") version "<pluginMarkerVersion>"
+}
+
+group = "com.example"
+version = "1.0"
+
+repositories {
+    mavenLocal()
+    jcenter()
+}
+
+kotlin.sourceSets {
+    getByName("main") {
+        dependencies {
+            implementation(kotlin("stdlib-js"))
+        }
+    }
+
+    getByName("test") {
+        dependencies {
+            implementation(kotlin("test-js"))
+            implementation(npm("mocha"))
+            implementation(npm("puppeteer"))
+        }
+    }
+}
+
+kotlin.target {
+    nodejs()
+}

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/resources/testProject/npm-dependencies-clash/settings.gradle.kts

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

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/resources/testProject/npm-dependencies-clash/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")
+}

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/resources/testProject/npm-dependencies-clash/src/test/kotlin/SimpleTest.kt

@@ -0,0 +1,16 @@
+/*
+ * 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
+
+import kotlin.test.Test
+import kotlin.test.assertTrue
+
+class SimpleTest {
+    @Test
+    fun simpleTest() {
+        assertTrue { true }
+    }
+}