add specific support to Gradle plugin publish plugin

CHANGELOG.md

@@ -9,10 +9,12 @@
   sources jar creation for Kotlin/JS projects anymore starting with 1.8.20. The `KotlinJs` constructor
   with a `sourcesJar` parameter has been deprecated.
 - Fix incompatibility with Gradle 8.1 for `java-test-fixtures` projects
+- Fix incompatibility with `com.gradle.plugin-publish` 1.0.0 and 1.1.0
 - New minimum supported versions:
   - Gradle 7.4
   - Android Gradle Plugin 7.3.0
   - Kotlin Gradle Plugin 1.7.0
+  - `com.gradle.plugin-publish` 1.0.0
 - Note: Starting with Kotlin 1.8.20-Beta the `common` sources jar for multiplatform projects will only contain
   the sources of the common source set instead of containing the sources from all source sets.
 

README.md

@@ -20,6 +20,7 @@ The output of the following Gradle plugins is supported to be published with thi
 - `java`
 - `java-library`
 - `java-gradle-plugin`
+- `com.gradle.plugin-publish`
 - `java-platform`
 - `version-catalog`
 

docs/base.md

@@ -299,8 +299,8 @@ For projects using the `org.jetbrains.kotlin.multiplatform` plugin.
 
 ### Gradle Plugin
 
-
-For projects using the `java-gradle-plugin` plugin.
+For projects using the `java-gradle-plugin` plugin. When also using `com.gradle.plugin-publish` please
+use [GradlePublishPlugin](#gradle-publish-plugin)
 
 === "build.gradle"
 
@@ -338,6 +338,31 @@ For projects using the `java-gradle-plugin` plugin.
     }
     ```
 
+### Gradle Publish Plugin
+
+For projects using the `com.gradle.plugin-publish` plugin. This will always publish a sources jar
+and a javadoc jar.
+
+=== "build.gradle"
+
+    ```groovy
+    import com.vanniktech.maven.publish.GradlePublishPlugin
+
+    mavenPublishing {
+      configure(new GradlePublishPlugin())
+    }
+    ```
+
+=== "build.gradle.kts"
+
+    ```kotlin
+    import com.vanniktech.maven.publish.GradlePublishPlugin
+
+    mavenPublishing {
+      configure(GradlePublishPlugin())
+    }
+    ```
+
 ### Java Platform
 
 

plugin/src/integrationTest/kotlin/com/vanniktech/maven/publish/MavenPublishPluginPlatformTest.kt

@@ -125,6 +125,36 @@ class MavenPublishPluginPlatformTest {
     )
   }
 
+  @TestParameterInjectorTest
+  fun javaGradlePluginWithPluginPublishProject(@TestParameter gradlePluginPublish: GradlePluginPublish) {
+    val project = javaGradlePluginWithGradlePluginPublish(gradlePluginPublish)
+    val result = project.run(fixtures, testProjectDir, testOptions)
+
+    assertThat(result).outcome().succeeded()
+    assertThat(result).artifact("jar").exists()
+    assertThat(result).artifact("jar").isSigned()
+    assertThat(result).pom().exists()
+    assertThat(result).pom().isSigned()
+    assertThat(result).pom().matchesExpectedPom()
+    assertThat(result).module().exists()
+    assertThat(result).module().isSigned()
+    assertThat(result).sourcesJar().exists()
+    assertThat(result).sourcesJar().isSigned()
+    assertThat(result).sourcesJar().containsAllSourceFiles()
+    assertThat(result).javadocJar().exists()
+    assertThat(result).javadocJar().isSigned()
+
+    val pluginId = "com.example.test-plugin"
+    val pluginMarkerSpec = project.copy(group = pluginId, artifactId = "$pluginId.gradle.plugin")
+    val pluginMarkerResult = result.copy(projectSpec = pluginMarkerSpec)
+    assertThat(pluginMarkerResult).pom().exists()
+    assertThat(pluginMarkerResult).pom().isSigned()
+    assertThat(pluginMarkerResult).pom().matchesExpectedPom(
+      "pom",
+      PomDependency("com.example", "test-artifact", "1.0.0", null),
+    )
+  }
+
   @TestParameterInjectorTest
   fun javaGradlePluginKotlinProject(
     @TestParameter(valuesProvider = KotlinVersionProvider::class) kotlinVersion: KotlinVersion,

plugin/src/integrationTest/kotlin/com/vanniktech/maven/publish/ProjectSpecRunner.kt

@@ -171,6 +171,7 @@ private fun writeSettingFile(path: Path) {
             mavenLocal()
             mavenCentral()
             google()
+            gradlePluginPortal()
         }
     }
 

plugin/src/integrationTest/kotlin/com/vanniktech/maven/publish/ProjectSpecs.kt

@@ -13,6 +13,7 @@ val kotlinMultiplatformPlugin = PluginSpec("org.jetbrains.kotlin.multiplatform")
 val kotlinJsPlugin = PluginSpec("org.jetbrains.kotlin.js")
 val kotlinAndroidPlugin = PluginSpec("org.jetbrains.kotlin.android")
 val androidLibraryPlugin = PluginSpec("com.android.library")
+val gradlePluginPublishPlugin = PluginSpec("com.gradle.plugin-publish")
 
 val fixtures = Paths.get("src/integrationTest/fixtures2").toAbsolutePath()
 
@@ -88,6 +89,14 @@ fun javaGradlePluginProjectSpec() = ProjectSpec(
   basePluginConfig = "configure(new GradlePlugin(new JavadocJar.Empty(), true))",
 )
 
+fun javaGradlePluginWithGradlePluginPublish(gradlePluginPublish: GradlePluginPublish): ProjectSpec {
+  val base = javaGradlePluginProjectSpec()
+  return base.copy(
+    plugins = base.plugins + gradlePluginPublishPlugin.copy(version = gradlePluginPublish.version),
+    basePluginConfig = "configure(new GradlePublishPlugin())",
+  )
+}
+
 fun javaGradlePluginKotlinProjectSpec(version: KotlinVersion): ProjectSpec {
   val plainJavaGradlePluginProject = javaGradlePluginProjectSpec()
   return plainJavaGradlePluginProject.copy(

plugin/src/integrationTest/kotlin/com/vanniktech/maven/publish/TestOptions.kt

@@ -80,3 +80,11 @@ enum class GradleVersion(val value: String) {
     val GRADLE_7_6 = GRADLE_8_0
   }
 }
+
+enum class GradlePluginPublish(val version: String) {
+  // minimum supported
+  GRADLE_PLUGIN_PUBLISH_1_0("1.0.0"),
+
+  // stable
+  GRADLE_PLUGIN_PUBLISH_1_1("1.1.0"),
+}

plugin/src/main/kotlin/com/vanniktech/maven/publish/MavenPublishPlugin.kt

@@ -50,6 +50,8 @@ private fun Project.configurePlatform() {
     when {
       plugins.hasPlugin("org.jetbrains.kotlin.multiplatform") -> {} // Handled above.
       plugins.hasPlugin("com.android.library") -> {} // Handled above.
+      plugins.hasPlugin("com.gradle.plugin-publish") ->
+        baseExtension.configure(GradlePublishPlugin())
       plugins.hasPlugin("java-gradle-plugin") ->
         baseExtension.configure(GradlePlugin(defaultJavaDocOption() ?: javadoc()))
       plugins.hasPlugin("org.jetbrains.kotlin.jvm") ->

plugin/src/main/kotlin/com/vanniktech/maven/publish/Platform.kt

@@ -91,6 +91,22 @@ data class GradlePlugin @JvmOverloads constructor(
   }
 }
 
+/**
+ * To be used for `com.gradle.plugin-publish` projects. Uses the default publication that gets created by that plugin.
+ */
+class GradlePublishPlugin : Platform() {
+
+  override val javadocJar: JavadocJar = JavadocJar.Javadoc()
+  override val sourcesJar: Boolean = true
+
+  override fun configure(project: Project) {
+    // setup is fully handled by com.gradle.plugin-publish already
+  }
+
+  override fun equals(other: Any?): Boolean = other is GradlePublishPlugin
+  override fun hashCode(): Int = this::class.hashCode()
+}
+
 /**
  * To be used for `com.android.library` projects. Applying this creates a publication for the component of the given
  * `variant`. Depending on the passed parameters for [javadocJar] and [sourcesJar], `-javadoc` and `-sources` jars will