Migrate junitJupiterExtensionTest subproject to kotlin dsl (mockito#1704

)

settings.gradle.kts

@@ -12,10 +12,18 @@ include("deprecatedPluginsTest",
 
 rootProject.name = "mockito"
 
+val koltinBuildScriptProject = hashSetOf("junitJupiterExtensionTest")
+
+fun buildFileExtensionFor(projectName: String) =
+    if (projectName in koltinBuildScriptProject) ".gradle.kts" else ".gradle"
+
+fun buildFileFor(projectName: String) =
+    "$projectName${buildFileExtensionFor(projectName)}"
+
 rootProject.children.forEach { project ->
     val projectDirName = "subprojects/${project.name}"
     project.projectDir = File(settingsDir, projectDirName)
-    project.buildFileName = "${project.name}.gradle"
+    project.buildFileName = buildFileFor(project.name)
     require(project.projectDir.isDirectory) {
         "Project directory ${project.projectDir} for project ${project.name} does not exist."
     }

subprojects/junitJupiterExtensionTest/junitJupiterExtensionTest.gradle.kts

@@ -0,0 +1,28 @@
+apply(from = "$rootDir/gradle/dependencies.gradle")
+
+plugins {
+    java
+}
+
+description = "End-to-end tests for automatic registration of MockitoExtension."
+
+java {
+    sourceCompatibility = JavaVersion.VERSION_1_8
+}
+dependencies {
+    testCompile(project(":junit-jupiter"))
+    testCompile(library("assertj"))
+    testCompile(library("junitPlatformLauncher"))
+    testCompile(library("junitJupiterApi"))
+    testRuntime(library("junitJupiterEngine"))
+}
+
+tasks.named<Test>("test") {
+    useJUnitPlatform()
+}
+
+val Project.libraries
+    get() = rootProject.extra["libraries"] as Map<String, Any>
+
+fun Project.library(name: String) =
+    libraries[name]!!