attribute(Category.CATEGORY_ATTRIBUTE, objects.named(Category.DOCUMENTATION))
            attribute(DocsType.DOCS_TYPE_ATTRIBUTE, objects.named("gradle-source-folders"))
        }
        val main = sourceSets.main.get()
        main.java.srcDirs.forEach {
            outgoing.artifact(it)
        }
        main.groovy.srcDirs.forEach {
            outgoing.artifact(it)
        }
        main.resources.srcDirs.forEach {

        buildFile << """
            sourceSets {
                plugin {
                    java {
                        srcDir 'src/plugin/java'
                        compileClasspath = configurations.compileClasspath
                    }
                }
            }

            gradlePlugin {
                pluginSourceSet sourceSets.plugin
            }
        """

        given:
        settingsFile << """
            rootProject.name = 'somelib'
        """
        buildFile << """
            plugins { id 'java' }

            sourceSets.main.java.srcDir("src/common/java")
        """
        file("src/common/java/OtherThing.java") << """
            class OtherThing {
            }
        """
        file("src/main/java/Thing.java") << """

----
plugins {
    id("java-library")
}

sourceSets {
    create("feature")
}

java {
    registerFeature("feature") {
        usingSourceSet(sourceSets["feature"])
    }
}
----
======
[.multi-language-sample]
======
.build.gradle
[source,groovy]
----
plugins {
    id("java-library")
}

sourceSets {
    feature
}

java {

            }
        }

        createDir("b") {
            file("build.gradle") << """
                plugins { id 'java' }
                dependencies { implementation project(":a") }
                sourceSets.main.java.srcDir "other"
            """
            dir("src/main/java") {
                file("Thing.java") << "class Thing {}"
            }
            dir("other") {

[source,kotlin]
----
tasks.compileJava {
    // Modify the task behavior
    doLast {
        val outputDir = File("$buildDir/compiledClasses")
        outputDir.mkdirs()

        val compiledFiles = sourceSets["main"].output.files
        compiledFiles.forEach { compiledFile ->
            val destinationFile = File(outputDir, compiledFile.name)
            compiledFile.copyTo(destinationFile, true)
        }

    jvmArgumentProviders.add(installationEnvProvider)

    // For unknown reason, this is set to 'sourceSet.getRuntimeClasspath()' in the 'org.gradle.samples' plugin
    testClassesDirs = sourceSets.docsTest.output.classesDirs
    // 'integTest.samplesdir' is set to an absolute path by the 'org.gradle.samples' plugin
    systemProperties.clear()

    filter {

Separating capabilities from conventions in plugins allows users to choose which tasks and conventions to apply.

For example, the Java Base plugin provides un-opinionated (i.e., generic) functionality like `SourceSets`, while the Java plugin adds tasks and conventions familiar to Java developers like `classes`, `jar` or `javadoc`.

Method <org.gradle.api.tasks.SourceSet.java(groovy.lang.Closure)> has arguments/return type groovy.lang.Closure that is not Gradle public API or primitive or built-in JDK classes or Kotlin classes in (SourceSet.java:0)

    }

    TestFile report(String sourceSet, String ext = 'html') {
        file(reportPath(sourceSet, ext))
    }

    TestFile report(File projectDir, String sourceSet, String ext = 'html') {
        new TestFile(projectDir, reportPath(sourceSet, ext))
    }

    private String reportPath(String sourceSet, String ext) {
        return "build/reports/codenarc/${sourceSet}.${ext}"
    }

    TestFile writeRuleFile() {