title: How do I use the native JUnit 5 support in Gradle with the Kotlin DSL?
body: <p>I want to use the built-in JUnit 5 with the Gradle Kotlin DSL, because during build I get this warning:</p>
  
  <pre><code>WARNING: The junit-platform-gradle-plugin is deprecated and will be discontinued in JUnit Platform 1.3.
  Please use Gradle's native support for running tests on the JUnit Platform (requires Gradle 4.6 or higher):
  https://junit.org/junit5/docs/current/user-guide/#running-tests-build-gradle
  </code></pre>
  
  <p>That links tells me to put</p>
  
  <pre><code>test {
      useJUnitPlatform()
  }
  </code></pre>
  
  <p>in my <code>build.gradle</code>, but what is the syntax for <code>build.gradle.kts</code>?</p>
  
  <p>My current build file is</p>
  
  <pre><code>import org.gradle.api.plugins.ExtensionAware
  
  import org.junit.platform.gradle.plugin.FiltersExtension
  import org.junit.platform.gradle.plugin.EnginesExtension
  import org.junit.platform.gradle.plugin.JUnitPlatformExtension
  
  group = "com.example"
  version = "0.0"
  
  // JUnit 5
  buildscript {
      repositories {
          mavenCentral()
          jcenter()
      }
      dependencies {
          classpath("org.junit.platform:junit-platform-gradle-plugin:1.2.0")
      }
  }
  
  apply {
      plugin("org.junit.platform.gradle.plugin")
  }
  
  // Kotlin configuration.
  plugins {
  
      val kotlinVersion = "1.2.41"
  
      application
      kotlin("jvm") version kotlinVersion
      java // Required by at least JUnit.
  
      // Plugin which checks for dependency updates with help/dependencyUpdates task.
      id("com.github.ben-manes.versions") version "0.17.0"
  
      // Plugin which can update Gradle dependencies, use help/useLatestVersions
      id("se.patrikerdes.use-latest-versions") version "0.2.1"
  
  }
  
  application {
      mainClassName = "com.example.HelloWorld"
  }
  
  dependencies {
      compile(kotlin("stdlib"))
      // To "prevent strange errors".
      compile(kotlin("reflect"))
      // Kotlin reflection.
      compile(kotlin("test"))
      compile(kotlin("test-junit"))
  
      // JUnit 5
      testImplementation("org.junit.jupiter:junit-jupiter-api:5.2.0")
      testRuntimeOnly("org.junit.jupiter:junit-jupiter-engine:5.2.0")
      testRuntime("org.junit.platform:junit-platform-console:1.2.0")
  
      // Kotlintest
      testCompile("io.kotlintest:kotlintest-core:3.1.0-RC2")
      testCompile("io.kotlintest:kotlintest-assertions:3.1.0-RC2")
      testCompile("io.kotlintest:kotlintest-runner-junit5:3.1.0-RC2")
  
  }
  
  repositories {
      mavenCentral()
      mavenLocal()
      jcenter()
  }
  </code></pre>
  
  <p>(The following is some blabla because this question 'contains mostly code').
  I tried to find documentation on how to customize tasks in the Kotlin DSL, but I couldn't find any. In normal Groovy you can just write the name of the task and then change things in the block, but the Kotlin DSL doesn't recognise the task as such, unresolved reference.</p>
  
  <p>Also, this question is related but asks for creating of <em>new</em> tasks, instead of customize existing tasks: <a href="https://stackoverflow.com/questions/48553029/how-do-i-overwrite-a-task-in-gradle-kotlin-dsl">How do I overwrite a task in gradle kotlin-dsl</a></p>
  
  <p><a href="https://stackoverflow.com/a/49014534/4126843">Here is a solution for normal Gradle.</a></p>