Add Dokka configuration method

buildSrc/build.gradle.kts

@@ -1,11 +1,27 @@
+import java.util.*
+
 plugins {
     `kotlin-dsl`
 }
 
 repositories {
     gradlePluginPortal()
+    maven("https://kotlin.bintray.com/kotlin-eap")
+    maven("https://kotlin.bintray.com/kotlin-dev")
 }
 
 kotlinDslPluginOptions {
     experimentalWarning.set(false)
 }
+
+val props = Properties().apply {
+    file("../gradle.properties").inputStream().use { load(it) }
+}
+
+fun version(target: String): String =
+    props.getProperty("${target}_version")
+
+dependencies {
+    implementation(kotlin("gradle-plugin", version("kotlin")))
+    implementation("org.jetbrains.dokka:dokka-gradle-plugin:${version("dokka")}")
+}

buildSrc/src/main/kotlin/Dokka.kt

@@ -0,0 +1,23 @@
+/*
+ * Copyright 2016-2020 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license.
+ */
+
+import org.gradle.api.Project
+import org.gradle.kotlin.dsl.delegateClosureOf
+import org.gradle.kotlin.dsl.withType
+import org.jetbrains.dokka.DokkaConfiguration.ExternalDocumentationLink.Builder
+import org.jetbrains.dokka.gradle.DokkaTask
+import java.io.File
+import java.net.URL
+
+fun Project.externalDocumentationLink(
+    url: String,
+    packageList: File = projectDir.resolve("package.list")
+) {
+    tasks.withType<DokkaTask>().configureEach {
+        externalDocumentationLink(delegateClosureOf<Builder> {
+            this.url = URL(url)
+            packageListUrl = packageList.toPath().toUri().toURL()
+        })
+    }
+}

reactive/kotlinx-coroutines-reactive/build.gradle.kts

@@ -2,42 +2,33 @@
  * Copyright 2016-2020 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license.
  */
 
-import org.jetbrains.dokka.DokkaConfiguration.ExternalDocumentationLink
-import org.jetbrains.dokka.gradle.DokkaTask
-import java.net.URL
-
 val reactiveStreamsVersion = property("reactive_streams_version")
 
 dependencies {
     compile("org.reactivestreams:reactive-streams:$reactiveStreamsVersion")
     testCompile("org.reactivestreams:reactive-streams-tck:$reactiveStreamsVersion")
 }
 
-tasks {
-    val testNG = register<Test>("testNG") {
-        useTestNG()
-        reports.html.destination = file("$buildDir/reports/testng")
-        include("**/*ReactiveStreamTckTest.*")
-        // Skip testNG when tests are filtered with --tests, otherwise it simply fails
-        onlyIf {
-            filter.includePatterns.isEmpty()
-        }
-        doFirst {
-            // Classic gradle, nothing works without doFirst
-            println("TestNG tests: ($includes)")
-        }
+val testNG by tasks.registering(Test::class) {
+    useTestNG()
+    reports.html.destination = file("$buildDir/reports/testng")
+    include("**/*ReactiveStreamTckTest.*")
+    // Skip testNG when tests are filtered with --tests, otherwise it simply fails
+    onlyIf {
+        filter.includePatterns.isEmpty()
     }
-
-    named<Test>("test") {
-        reports.html.destination = file("$buildDir/reports/junit")
-
-        dependsOn(testNG)
+    doFirst {
+        // Classic gradle, nothing works without doFirst
+        println("TestNG tests: ($includes)")
     }
+}
 
-    withType<DokkaTask>().configureEach {
-        externalDocumentationLink(delegateClosureOf<ExternalDocumentationLink.Builder> {
-            url = URL("https://www.reactive-streams.org/reactive-streams-$reactiveStreamsVersion-javadoc/")
-            packageListUrl = projectDir.toPath().resolve("package.list").toUri().toURL()
-        })
-    }
+tasks.test {
+    reports.html.destination = file("$buildDir/reports/junit")
+
+    dependsOn(testNG)
 }
+
+externalDocumentationLink(
+    url = "https://www.reactive-streams.org/reactive-streams-$reactiveStreamsVersion-javadoc/"
+)

ui/kotlinx-coroutines-android/build.gradle.kts

@@ -2,10 +2,6 @@
  * Copyright 2016-2020 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license.
  */
 
-import org.jetbrains.dokka.DokkaConfiguration.ExternalDocumentationLink
-import org.jetbrains.dokka.gradle.DokkaTask
-import java.net.URL
-
 repositories {
     google()
 }
@@ -100,9 +96,6 @@ tasks.test {
     }
 }
 
-tasks.withType<DokkaTask>().configureEach {
-    externalDocumentationLink(delegateClosureOf<ExternalDocumentationLink.Builder> {
-        url = URL("https://developer.android.com/reference/")
-        packageListUrl = projectDir.toPath().resolve("package.list").toUri().toURL()
-    })
-}
+externalDocumentationLink(
+    url = "https://developer.android.com/reference/"
+)