import org.gradle.api.Transformer;
import org.gradle.api.file.FileCopyDetails;
import org.gradle.api.file.RelativePath;

public class RenamingCopyAction implements Action<FileCopyDetails> {
    private final Transformer<String, String> transformer;

    public RenamingCopyAction(Transformer<String, String> transformer) {
        this.transformer = transformer;
    }

    @Override

import spock.lang.Specification

class RenamingCopyActionTest extends Specification {

    Transformer transformer = Mock()
    FileCopyDetails details = Mock()
    RenamingCopyAction action

    def setup() {
        action = new RenamingCopyAction(transformer)
        details.getRelativePath() >> new RelativePath(true, "a", "b")
    }

    def 'transforms last segment of path with non-null input'() {
        when:

import org.gradle.api.file.FileCollection;
import org.gradle.api.internal.file.copy.CopySpecInternal;
import org.gradle.api.internal.file.copy.DefaultCopySpec;
import org.gradle.api.internal.file.copy.RenamingCopyAction;
import org.gradle.api.model.ObjectFactory;
import org.gradle.api.tasks.Classpath;
import org.gradle.api.tasks.InputFile;
import org.gradle.api.tasks.Internal;
import org.gradle.api.tasks.Optional;

        copyAction instanceof RenamingCopyAction
        copyAction.transformer instanceof RegExpNameMapper

        where:
        regexp << ["regexp", /regexp/]
    }

    def 'adds rename Closure to actions'() {
        when:
        spec.rename {}

        then:
        spec.copyActions.size() == 1
        spec.copyActions[0] instanceof RenamingCopyAction
    }

    def 'add action'() {

    public CopySpec rename(String sourceRegEx, String replaceWith) {
        appendCopyAction(new RenamingCopyAction(new RegExpNameMapper(sourceRegEx, replaceWith)));
        return this;
    }

    @Override
    public CopySpec rename(Pattern sourceRegEx, String replaceWith) {
        appendCopyAction(new RenamingCopyAction(new RegExpNameMapper(sourceRegEx, replaceWith)));
        return this;
    }

    @Override