Add a function attributes { } to KotlinTarget and KotlinCompilation

Gradle has a function `attributes { ... }` for `Configuration`, so we
can introduce one, too, for uniformity of the DSLs. This will configure
the `val attributes: AttributeContainer` of the `KotlinTarget` and
`KotlinCompilation`.

Issue #KT-27682 Fixed

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

@@ -7,6 +7,7 @@ package org.jetbrains.kotlin.gradle.plugin
 
 import groovy.lang.Closure
 import org.gradle.api.Named
+import org.gradle.api.attributes.AttributeContainer
 import org.gradle.api.attributes.HasAttributes
 import org.gradle.api.file.ConfigurableFileCollection
 import org.gradle.api.file.FileCollection
@@ -52,6 +53,9 @@ interface KotlinCompilation<out T : KotlinCommonOptions> : Named, HasAttributes,
     fun kotlinOptions(configure: T.() -> Unit)
     fun kotlinOptions(configure: Closure<*>) = kotlinOptions { ConfigureUtil.configure(configure, this) }
 
+    fun attributes(configure: AttributeContainer.() -> Unit) = configure(attributes)
+    fun attributes(configure: Closure<*>) = attributes { ConfigureUtil.configure(configure, this) }
+
     val compileAllTaskName: String
 
     companion object {

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

@@ -10,6 +10,7 @@ import org.gradle.api.Action
 import org.gradle.api.Named
 import org.gradle.api.NamedDomainObjectContainer
 import org.gradle.api.Project
+import org.gradle.api.attributes.AttributeContainer
 import org.gradle.api.attributes.HasAttributes
 import org.gradle.api.component.SoftwareComponent
 import org.gradle.api.internal.component.UsageContext
@@ -47,6 +48,9 @@ interface KotlinTarget : Named, HasAttributes {
     fun mavenPublication(action: Closure<Unit>)
     fun mavenPublication(action: Action<MavenPublication>)
 
+    fun attributes(configure: AttributeContainer.() -> Unit) = configure(attributes)
+    fun attributes(configure: Closure<*>) = attributes { ConfigureUtil.configure(configure, this) }
+
     val preset: KotlinTargetPreset<out KotlinTarget>?
 
     override fun getName(): String = targetName

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

@@ -1202,6 +1202,23 @@ class NewMultiplatformIT : BaseGradleIT() {
         testDependencies()
     }
 
+    @Test
+    fun testMultipleTargetsSamePlatform() = with(Project("newMppMultipleTargetsSamePlatform", gradleVersion)) {
+        testResolveAllConfigurations("app") {
+            assertContains(">> :app:junitCompileClasspath --> lib-junit.jar")
+            assertContains(">> :app:junitCompileClasspath --> junit-4.12.jar")
+
+            assertContains(">> :app:mixedJunitCompileClasspath --> lib-junit.jar")
+            assertContains(">> :app:mixedJunitCompileClasspath --> junit-4.12.jar")
+
+            assertContains(">> :app:testngCompileClasspath --> lib-testng.jar")
+            assertContains(">> :app:testngCompileClasspath --> testng-6.14.3.jar")
+
+            assertContains(">> :app:mixedTestngCompileClasspath --> lib-testng.jar")
+            assertContains(">> :app:mixedTestngCompileClasspath --> testng-6.14.3.jar")
+        }
+    }
+
     @Test
     fun testUnusedSourceSetsReport() = with(Project("sample-lib", gradleVersion, "new-mpp-lib-and-app")) {
         setupWorkingDir()

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

@@ -0,0 +1,26 @@
+plugins {
+	id("org.jetbrains.kotlin.multiplatform")
+}
+
+val testFrameworkAttribute = Attribute.of("com.example.testFramework", String::class.java)
+
+kotlin {
+	configure(listOf(jvm("junit"), jvm("testng"))) {
+		attributes {
+			attribute(testFrameworkAttribute, targetName)
+		}
+	}
+
+	jvm("mixed") {
+		configure(listOf(compilations.create("junit"), compilations.create("testng"))) {
+			defaultSourceSet.dependsOn(sourceSets["commonMain"])
+			attributes {
+				attribute(testFrameworkAttribute, compilationName)
+			}
+		}
+	}
+
+	sourceSets["commonMain"].dependencies {
+		implementation(project(":lib"))
+	}
+}

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/resources/testProject/newMppMultipleTargetsSamePlatform/build.gradle

@@ -0,0 +1,16 @@
+buildscript {
+	repositories {
+		mavenLocal()
+		jcenter()
+	}
+	dependencies {
+		classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
+	}
+}
+
+allprojects {
+	repositories {
+		mavenLocal()
+		jcenter()
+	}
+}

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

@@ -0,0 +1,21 @@
+plugins {
+	id("org.jetbrains.kotlin.multiplatform")
+}
+
+val testFrameworkAttribute = Attribute.of("com.example.testFramework", String::class.java)
+
+kotlin {
+	configure(listOf(jvm("junit"), jvm("testng"))) {
+		attributes {
+			attribute(testFrameworkAttribute, targetName)
+		}
+	}
+
+	jvm("junit").compilations["main"].defaultSourceSet.dependencies {
+		api("junit:junit:4.12")
+	}
+
+	jvm("testng").compilations["main"].defaultSourceSet.dependencies {
+		api("org.testng:testng:6.14.3")
+	}
+}

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/resources/testProject/newMppMultipleTargetsSamePlatform/lib/src/commonMain/kotlin/testAnnotation.kt

@@ -0,0 +1,3 @@
+package com.example
+
+expect annotation class Test()

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/resources/testProject/newMppMultipleTargetsSamePlatform/lib/src/junitMain/kotlin/junitTestAnnotation.kt

@@ -0,0 +1,3 @@
+package com.example
+
+actual typealias Test = org.junit.Test

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/resources/testProject/newMppMultipleTargetsSamePlatform/lib/src/testngMain/kotlin/testngTestAnnotation.kt

@@ -0,0 +1,3 @@
+package com.example
+
+actual typealias Test = org.testng.annotations.Test

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/resources/testProject/newMppMultipleTargetsSamePlatform/settings.gradle

@@ -0,0 +1 @@
+include ':lib', ':app'