Rename implement to expectedBy in Gradle, deprecate the old name

Issue #KT-20618 Fixed

(cherry picked from commit 6e0d378)

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

@@ -20,6 +20,7 @@ import org.gradle.api.logging.LogLevel
 import com.intellij.openapi.util.io.FileUtil
 import org.jetbrains.kotlin.gradle.plugin.CopyClassesToJavaOutputStatus
 import org.jetbrains.kotlin.gradle.tasks.USING_INCREMENTAL_COMPILATION_MESSAGE
+import org.jetbrains.kotlin.gradle.plugin.IMPLEMENT_CONFIG_WARNING
 import org.jetbrains.kotlin.gradle.util.*
 import org.junit.Test
 import java.io.File
@@ -406,6 +407,26 @@ class KotlinGradleIT: BaseGradleIT() {
         }
     }
 
+    @Test
+    fun testDeprecatedImplementWarning() {
+        val project = Project("multiplatformProject", GRADLE_VERSION)
+        val warningText = IMPLEMENT_CONFIG_WARNING
+
+        project.build("build") {
+            assertSuccessful()
+            assertNotContains(warningText)
+        }
+
+        project.projectDir.walk().filter { it.name == "build.gradle" }.forEach { buildGradle ->
+            buildGradle.modify { it.replace("expectedBy", "implement") }
+        }
+
+        project.build("build") {
+            assertSuccessful()
+            assertContains(warningText)
+        }
+    }
+
     @Test
     fun testFreeCompilerArgs() {
         val project = Project("kotlinProject", GRADLE_VERSION)

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

@@ -1,5 +1,5 @@
 apply plugin: 'kotlin-platform-js'
 
 dependencies {
-    implement project(":lib")
+    expectedBy project(":lib")
 }

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

@@ -1,6 +1,6 @@
 apply plugin: 'kotlin-platform-jvm'
 
 dependencies {
-    implement project(":lib")
+    expectedBy project(":lib")
     compile 'com.google.guava:guava:20.0'
 }

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

@@ -35,6 +35,8 @@ open class KotlinPlatformCommonPlugin : KotlinPlatformPluginBase("common") {
     }
 }
 
+const val IMPLEMENT_CONFIG_WARNING = "The 'implement' configuration is deprecated and will be removed. Use 'expectedBy' instead."
+
 open class KotlinPlatformImplementationPluginBase(platformName: String) : KotlinPlatformPluginBase(platformName) {
     private val commonProjects = arrayListOf<Project>()
     private val platformKotlinTasksBySourceSetName = hashMapOf<String, AbstractKotlinCompile<*>>()
@@ -47,13 +49,29 @@ open class KotlinPlatformImplementationPluginBase(platformName: String) : Kotlin
         project.tasks.filterIsInstance<AbstractKotlinCompile<*>>().associateByTo(platformKotlinTasksBySourceSetName) { it.sourceSetName }
 
         val implementConfig = project.configurations.create("implement")
-        implementConfig.isTransitive = false
-        implementConfig.dependencies.whenObjectAdded { dep ->
-            if (dep is ProjectDependency) {
-                addCommonProject(dep.dependencyProject, project)
+        val expectedByConfig = project.configurations.create("expectedBy").apply {
+            extendsFrom(implementConfig)
+        }
+
+        listOf(implementConfig, expectedByConfig).forEach { config ->
+            config.isTransitive = false
+
+            config.dependencies.whenObjectAdded { dep ->
+                if (dep is ProjectDependency) {
+                    addCommonProject(dep.dependencyProject, project)
+                }
+                else {
+                    throw GradleException("$project '${config.name}' dependency is not a project: $dep")
+                }
             }
-            else {
-                throw GradleException("$project `implement` dependency is not a project: $dep")
+        }
+
+        var implementDeprecationWarningShown = false
+
+        implementConfig.dependencies.whenObjectAdded {
+            if (!implementDeprecationWarningShown) {
+                implementDeprecationWarningShown = true
+                project.logger.kotlinWarn(IMPLEMENT_CONFIG_WARNING)
             }
         }
     }
@@ -61,12 +79,12 @@ open class KotlinPlatformImplementationPluginBase(platformName: String) : Kotlin
     private fun addCommonProject(commonProject: Project, platformProject: Project) {
         commonProjects.add(commonProject)
         if (commonProjects.size > 1) {
-            throw GradleException("Platform project $platformProject implements more than one common project: ${commonProjects.joinToString()}")
+            throw GradleException("Platform project $platformProject is expected by more than one common project: ${commonProjects.joinToString()}")
         }
 
         commonProject.whenEvaluated {
             if ((!commonProject.plugins.hasPlugin(KotlinPlatformCommonPlugin::class.java))) {
-                throw GradleException("Platform project $platformProject implements non-common project $commonProject (`apply plugin 'kotlin-platform-kotlin'`)")
+                throw GradleException("Platform project $platformProject is expected by non-common project $commonProject (`apply plugin 'kotlin-platform-kotlin'`)")
             }
 
             commonProject.sourceSets.all { commonSourceSet ->