archrules library plugin should produce an outgoing variant for the archrules jar

Co-authored-by: Emily Yuan <[email protected]>

Author: wakingrufus

README.md

@@ -64,7 +64,11 @@ public class LibraryArchRules implements ArchRulesService {
 
 When authoring rules about the usage of your own library code, it is recommended to colocate your rules library in the
 same project as the library code. The ArchRules plugin will publish the rules in a separate Jar, and the Runner plugin
-will select that jar for running rules, but these rule classes will not end up up in the runtime classpath.
+will select that jar for running rules, but these rule classes will not end up in the runtime classpath.
+
+#### How it works
+
+The Archrules Library plugin produces a separate Jar for the `archRules` sourceset, which is exposed as an alternate variant of the library. 
 
 ## LICENSE
 

nebula-archrules-gradle-plugin/src/main/kotlin/com/netflix/nebula/archrules/gradle/ArchrulesLibraryPlugin.kt

@@ -2,9 +2,11 @@ package com.netflix.nebula.archrules.gradle
 
 import org.gradle.api.Plugin
 import org.gradle.api.Project
+import org.gradle.api.attributes.Usage
 import org.gradle.api.plugins.JavaPluginExtension
 import org.gradle.jvm.tasks.Jar
 import org.gradle.kotlin.dsl.getByType
+import org.gradle.kotlin.dsl.named
 import org.gradle.kotlin.dsl.register
 
 class ArchrulesLibraryPlugin : Plugin<Project> {
@@ -13,13 +15,21 @@ class ArchrulesLibraryPlugin : Plugin<Project> {
             val ext = project.extensions.getByType<JavaPluginExtension>()
             val archRulesSourceSet = ext.sourceSets.create("archRules")
             val version = ArchrulesLibraryPlugin::class.java.`package`.implementationVersion ?: "latest.release"
-            project.dependencies.add(archRulesSourceSet.implementationConfigurationName,
+            project.dependencies.add(
+                archRulesSourceSet.implementationConfigurationName,
                 "com.netflix.nebula:nebula-archrules-core:$version"
             )
             val jarTask = project.tasks.register<Jar>("archRulesJar") {
                 archiveClassifier.set("archrules")
                 from(archRulesSourceSet.output)
             }
+            val runtimeElements = project.configurations.getByName("runtimeElements")
+            runtimeElements.outgoing.variants.create("archRulesElements") {
+                attributes {
+                    attribute(Usage.USAGE_ATTRIBUTE, project.objects.named("arch-rules"))
+                }
+                artifact(jarTask)
+            }
         }
     }
 }

nebula-archrules-gradle-plugin/src/test/kotlin/com/netflix/nebula/archrules/gradle/ArchrulesLibraryPluginTest.kt

@@ -83,13 +83,19 @@ class ArchrulesLibraryPluginTest {
         assertThat(moduleMetadata)
             .`as`("Gradle Module Metadata is created")
             .exists()
+
         val moduleMetadataJson = moduleMetadata.readText()
-        println(moduleMetadataJson)
+
         assertThatJson(moduleMetadataJson)
             .inPath("$.variants[?(@.name=='runtimeElements')].files[0]")
             .isArray
             .first().isObject
             .containsEntry("name", "library-with-rules-0.0.1.jar")
 
+        assertThatJson(moduleMetadataJson)
+            .inPath("$.variants[?(@.name=='runtimeElementsArchRulesElements')].files[0]")
+            .isArray
+            .first().isObject
+            .containsEntry("name", "library-with-rules-0.0.1-archrules.jar")
     }
 }

nebula-archrules-gradle-plugin/src/test/kotlin/com/netflix/nebula/archrules/gradle/IntegrationTest.kt

@@ -49,6 +49,7 @@ internal class IntegrationTest {
 
         val result = runner.run("check") {
             withGradleVersion(gradleVersion.version)
+            forwardOutput()
         }
 
         assertThat(result.task(":library-with-rules:check"))