Exclude all immutable Groovy Files

build.gradle

List excludedGroovyClasses() {

    String srcDir = System.getProperty("user.dir") + "/src/main/groovy/"
    FileTree tree = fileTree(dir: 'src/main/groovy')
    tree.include '**/*.groovy'
    String immutableSign = 'import groovy.transform.Immutable'

    Collection excludedClasses = tree.findAll {
        it.text.contains(immutableSign)
    }.collect {
        it.absolutePath.replace(srcDir, "")
    }

    excludedClasses
}