Upgrade to Kotlin 1.2.30

See https://blog.jetbrains.com/kotlin/2018/03/kotlin-1-2-30-is-out for
details. As https://youtrack.jetbrains.com/issue/KT-21303 is fixed, this
commit enables Kotlin support on Java 10.

As https://youtrack.jetbrains.com/issue/KT-18497 was also fixed, the
special configuration needed to work correctly with the "java-library"
plugin is removed from the `junit-jupiter-api.gradle` script.

Closes junit-team#1169
Supersedes junit-team#1278

.travis.yml

@@ -37,7 +37,7 @@ script:
 # Display Gradle, Groovy, JVM and other versions
   - ./gradlew -version
 # Build JUnit 5
-  - ./gradlew build $EXTRA_GRADLE_ARGS --scan --stacktrace -Dkotlin.compiler.execution.strategy="in-process"
+  - ./gradlew build $EXTRA_GRADLE_ARGS --scan --stacktrace -Dkotlin.compiler.execution.strategy="in-process" --warning-mode=all
 
 # Do not store unnecessary files from Gradle dependency cache
 before_cache:

build.gradle

@@ -106,7 +106,7 @@ allprojects { subproj ->
 
 	apply plugin: 'java-library'
 	apply plugin: 'groovy' // apply for all projects so rootProject sees groovy output dir
-	if (gradle.ext.kotlinIsSupported) apply plugin: 'kotlin'
+	apply plugin: 'kotlin'
 	apply plugin: 'eclipse'
 	apply plugin: 'idea'
 	apply plugin: 'com.diffplug.gradle.spotless'
@@ -198,7 +198,7 @@ allprojects { subproj ->
 		options.compilerArgs += '-parameters'
 	}
 
-	if (gradle.ext.kotlinIsSupported) tasks.withType(org.jetbrains.kotlin.gradle.tasks.KotlinCompile) {
+	tasks.withType(org.jetbrains.kotlin.gradle.tasks.KotlinCompile) {
 		kotlinOptions {
 			jvmTarget = '1.8'
 			apiVersion = '1.1'
@@ -340,7 +340,7 @@ subprojects { subproj ->
 			options.encoding = 'UTF-8'
 			// Remove Kotlin classes from classpath due to "bad" class file: AssertionsKt$sam$Supplier$44378ebd.class
 			// see https://bugs.openjdk.java.net/browse/JDK-8187422
-			if (gradle.ext.kotlinIsSupported) classpath = classpath - files(compileKotlin.destinationDir)
+			classpath = classpath - files(compileKotlin.destinationDir)
 		}
 
 		task sourcesJar(type: Jar, dependsOn: classes) {

documentation/documentation.gradle

@@ -43,7 +43,7 @@ dependencies {
 	testImplementation(project(':junit-jupiter-params'))
 	testImplementation(project(':junit-platform-runner'))
 	testImplementation(project(':junit-platform-launcher'))
-	if (gradle.ext.kotlinIsSupported) testImplementation("org.jetbrains.kotlin:kotlin-stdlib:${kotlinVersion}")
+	testImplementation("org.jetbrains.kotlin:kotlin-stdlib:${kotlinVersion}")
 
 	// Include junit-platform-console so that the JUnit Gradle plugin
 	// uses the local version of the ConsoleLauncher.
@@ -121,6 +121,7 @@ asciidoctor {
 				'revnumber' : project.version,
 				'mainDir': project.sourceSets.main.java.srcDirs[0],
 				'testDir': project.sourceSets.test.java.srcDirs[0],
+				'kotlinTestDir': project.sourceSets.test.kotlin.srcDirs[0],
 				'consoleLauncherOptionsFile': consoleLauncherOptionsFile.toString(),
 				'experimentalApisTableFile': experimentalApisTableFile.toString(),
 				'testResourcesDir': project.sourceSets.test.resources.srcDirs[0],
@@ -132,7 +133,4 @@ asciidoctor {
 				'sectanchors': true,
 				'idprefix': '',
 				'idseparator': '-'
-	if (gradle.ext.kotlinIsSupported) {
-		attributes.put('kotlinTestDir', project.sourceSets.test.kotlin.srcDirs[0])
-	}
 }

gradle.properties

@@ -21,7 +21,7 @@ assertJVersion      = 3.9.1
 degraphVersion      = 0.1.4
 jmhVersion          = 1.20
 junit4Version       = 4.12
-kotlinVersion       = 1.2.21
+kotlinVersion       = 1.2.30
 log4jVersion        = 2.10.0
 mockitoVersion      = 2.15.0
 ota4jVersion        = 1.0.0

junit-jupiter-api/junit-jupiter-api.gradle

@@ -1,7 +1,7 @@
 dependencies {
 	api("org.opentest4j:opentest4j:${ota4jVersion}")
 	api(project(":junit-platform-commons"))
-	if (gradle.ext.kotlinIsSupported) compileOnly("org.jetbrains.kotlin:kotlin-stdlib:${kotlinVersion}")
+	compileOnly("org.jetbrains.kotlin:kotlin-stdlib:${kotlinVersion}")
 }
 
 jar {
@@ -11,22 +11,3 @@ jar {
 		)
 	}
 }
-
-configurations {
-	if (gradle.ext.kotlinIsSupported) apiElements {
-		/*
-		* Needed to configure kotlin to work correctly with the "java-library" plugin.
-		* See:
-		* https://docs.gradle.org/current/userguide/java_library_plugin.html#sec:java_library_known_issues
-		* https://youtrack.jetbrains.com/issue/KT-18497
-		*/
-		outgoing
-			.variants
-			.getByName("classes")
-			.artifact(
-				"file" : compileKotlin.destinationDir,
-				"type" : "java-classes-directory",
-				"builtBy" : compileKotlin
-			)
-	}
-}

junit-jupiter-engine/junit-jupiter-engine.gradle

@@ -17,20 +17,6 @@ test {
 }
 */
 
-// Disable these tests on Java 10 as they depend on working
-// Kotlin compilation.
-if (!gradle.ext.kotlinIsSupported) {
-	sourceSets {
-		test {
-			java {
-				srcDir 'src'
-				exclude '**/AtypicalJvmMethodNameTests**'
-				exclude '**/TestInstanceLifecycleKotlinTests**'
-			}
-		}
-	}
-}
-
 jar {
 	manifest {
 		attributes(
@@ -61,7 +47,7 @@ dependencies {
 	testImplementation(project(path: ':junit-platform-engine', configuration: 'testArtifacts'))
 	testImplementation("org.assertj:assertj-core:${assertJVersion}")
 	testImplementation("org.mockito:mockito-core:${mockitoVersion}")
-	if (gradle.ext.kotlinIsSupported) testImplementation("org.jetbrains.kotlin:kotlin-stdlib:${kotlinVersion}")
+	testImplementation("org.jetbrains.kotlin:kotlin-stdlib:${kotlinVersion}")
 
 	// Include junit-platform-console so that the JUnit Gradle plugin
 	// uses the local version of the ConsoleLauncher.

settings.gradle

@@ -5,11 +5,6 @@ if (javaVersion < 9) {
 		"Currently executing with Java " + javaVersion + ".")
 }
 
-// Disable Kotlin support on Java 10 or higher
-// Details at https://github.com/junit-team/junit5/issues/1169
-// Blocked by https://youtrack.jetbrains.com/issue/KT-21303
-gradle.ext.kotlinIsSupported = javaVersion < 10
-
 rootProject.name = 'junit5'
 
 include 'documentation'