add util function for adding external doc link

modules/dokkatoo-plugin/api/dokkatoo-plugin.api

@@ -137,6 +137,8 @@ public final class dev/adamko/dokkatoo/dokka/parameters/DokkaSourceSetIdSpec$Com
 }
 
 public abstract class dev/adamko/dokkatoo/dokka/parameters/DokkaSourceSetSpec : dev/adamko/dokkatoo/dokka/parameters/HasConfigurableVisibilityModifiers, java/io/Serializable, org/gradle/api/Named, org/gradle/api/plugins/ExtensionAware {
+	public final fun externalDocumentationLink (Ljava/net/URI;Lorg/gradle/api/Action;)Ldev/adamko/dokkatoo/dokka/parameters/DokkaExternalDocumentationLinkSpec;
+	public static synthetic fun externalDocumentationLink$default (Ldev/adamko/dokkatoo/dokka/parameters/DokkaSourceSetSpec;Ljava/net/URI;Lorg/gradle/api/Action;ILjava/lang/Object;)Ldev/adamko/dokkatoo/dokka/parameters/DokkaExternalDocumentationLinkSpec;
 	public abstract fun getAnalysisPlatform ()Lorg/gradle/api/provider/Property;
 	public abstract fun getApiVersion ()Lorg/gradle/api/provider/Property;
 	public abstract fun getClasspath ()Lorg/gradle/api/file/ConfigurableFileCollection;

modules/dokkatoo-plugin/src/main/kotlin/DokkatooBasePlugin.kt

@@ -228,6 +228,32 @@ constructor(
           url("https://kotlinlang.org/api/latest/jvm/stdlib/")
         }
 
+        maybeCreate("kotlinxCoroutines") {
+          // TODO link to coroutines docs
+          url("https://kotlinlang.org/api/latest/jvm/stdlib/")
+        }
+
+        maybeCreate("kotlinxDateTime") {
+          // TODO check if this is the right link to kotlinx-datetime docs
+          url("https://kotlinlang.org/api/kotlinx-datetime/")
+        }
+
+        maybeCreate("ktor") {
+          // TODO link to Ktor docs
+          url("https://kotlinlang.org/api/latest/jvm/stdlib/")
+        }
+
+        maybeCreate("gradle") {
+          // TODO link to Gradle docs
+          url("https://kotlinlang.org/api/latest/jvm/stdlib/")
+        }
+
+        // TODO get more links to existing docs
+        //      - Kotlinx Serialization
+
+        // TODO only add these links if source-set has a dependency that indicates the library is present
+        //      (e.g. if kotlinx-serialization-core is present, then enable kxs link)
+
         maybeCreate("androidSdk") {
           enabled.convention(this@dss.enableAndroidDocumentationLink)
           url("https://developer.android.com/reference/kotlin/")

modules/dokkatoo-plugin/src/main/kotlin/dokka/parameters/DokkaSourceSetSpec.kt

@@ -1,14 +1,22 @@
 package dev.adamko.dokkatoo.dokka.parameters
 
 import dev.adamko.dokkatoo.dokka.parameters.DokkaSourceSetIdSpec.Companion.dokkaSourceSetIdSpec
-import dev.adamko.dokkatoo.internal.*
+import dev.adamko.dokkatoo.internal.DokkatooInternalApi
+import dev.adamko.dokkatoo.internal.adding
+import dev.adamko.dokkatoo.internal.domainObjectContainer
 import java.io.Serializable
+import java.net.URI
 import javax.inject.Inject
-import org.gradle.api.*
+import org.gradle.api.Action
+import org.gradle.api.DomainObjectSet
+import org.gradle.api.Named
+import org.gradle.api.NamedDomainObjectContainer
 import org.gradle.api.file.ConfigurableFileCollection
 import org.gradle.api.model.ObjectFactory
 import org.gradle.api.plugins.ExtensionAware
-import org.gradle.api.provider.*
+import org.gradle.api.provider.Property
+import org.gradle.api.provider.Provider
+import org.gradle.api.provider.SetProperty
 import org.gradle.api.tasks.*
 import org.gradle.kotlin.dsl.*
 
@@ -351,6 +359,21 @@ constructor(
     )
   }
 
+  /**
+   * Add a new external documentation link to [externalDocumentationLinks].
+   *
+   * @see externalDocumentationLinks
+   * @see DokkaExternalDocumentationLinkSpec
+   */
+  fun externalDocumentationLink(
+    url: URI,
+    configure: Action<in DokkaExternalDocumentationLinkSpec> = Action {}
+  ): DokkaExternalDocumentationLinkSpec =
+    externalDocumentationLinks.create(url.toASCIIString()) {
+      this.url.set(url)
+      configure.execute(this)
+    }
+
   /**
    * Action for configuring package options, appending to [perPackageOptions].
    *

modules/dokkatoo-plugin/src/test/kotlin/dokka/parameters/builders/DokkaSourceSetBuilderTest.kt

@@ -3,10 +3,7 @@ package dev.adamko.dokkatoo.dokka.parameters.builders
 import dev.adamko.dokkatoo.DokkatooExtension
 import dev.adamko.dokkatoo.DokkatooPlugin
 import dev.adamko.dokkatoo.dokka.parameters.DokkaSourceSetSpec
-import dev.adamko.dokkatoo.utils.all_
-import dev.adamko.dokkatoo.utils.create_
-import dev.adamko.dokkatoo.utils.shouldContainAll
-import dev.adamko.dokkatoo.utils.sourceLink_
+import dev.adamko.dokkatoo.utils.*
 import io.kotest.assertions.throwables.shouldThrow
 import io.kotest.core.spec.style.FunSpec
 import io.kotest.engine.spec.tempdir
@@ -74,6 +71,17 @@ class DokkaSourceSetBuilderTest : FunSpec({
         }
       }
     }
+
+    test("expect externalDocumentationLink() util function adds link") {
+      val sourceSetSpec = project.createDokkaSourceSetSpec("test4")
+      val linkSpec =
+        sourceSetSpec.externalDocumentationLink_(URI("https://github.com/adamko-dev/dokkatoo/")) {
+          enabled.set(false)
+        }
+      linkSpec.name shouldBe "https://github.com/adamko-dev/dokkatoo/"
+      linkSpec.url.get() shouldBe URI("https://github.com/adamko-dev/dokkatoo/")
+      linkSpec.enabled.get() shouldBe false
+    }
   }
 
 

modules/dokkatoo-plugin/src/testFixtures/kotlin/samWithReceiverWorkarounds.kt

@@ -2,9 +2,11 @@
 
 package dev.adamko.dokkatoo.utils
 
+import dev.adamko.dokkatoo.dokka.parameters.DokkaExternalDocumentationLinkSpec
 import dev.adamko.dokkatoo.dokka.parameters.DokkaPackageOptionsSpec
 import dev.adamko.dokkatoo.dokka.parameters.DokkaSourceLinkSpec
 import dev.adamko.dokkatoo.dokka.parameters.DokkaSourceSetSpec
+import java.net.URI
 import org.gradle.api.DomainObjectCollection
 import org.gradle.api.NamedDomainObjectContainer
 import org.gradle.api.NamedDomainObjectProvider
@@ -77,3 +79,9 @@ fun DokkaSourceSetSpec.sourceLink_(
 fun DokkaSourceSetSpec.perPackageOption_(
   action: DokkaPackageOptionsSpec.() -> Unit
 ): Unit = perPackageOption(action)
+
+
+fun DokkaSourceSetSpec.externalDocumentationLink_(
+  url: URI,
+  action: DokkaExternalDocumentationLinkSpec.() -> Unit = {},
+): DokkaExternalDocumentationLinkSpec = externalDocumentationLink(url) { action() }