import org.gradle.api.tasks.bundling.Compression;

import java.io.File;
import java.io.InputStream;
import java.net.URI;

public class MaybeCompressedFileResource implements ReadableResourceInternal {

    private final ReadableResourceInternal resource;

    public MaybeCompressedFileResource(ReadableResourceInternal resource) {
        if (resource instanceof CompressedReadableResource) {
            // Already in something to uncompress it

        expect:
        def fileResource = this.fileResource("foo")
        new MaybeCompressedFileResource(fileResource).resource == fileResource
        new MaybeCompressedFileResource(this.fileResource("foo.tgz")).resource instanceof GzipArchiver
        new MaybeCompressedFileResource(this.fileResource("foo.gz")).resource instanceof GzipArchiver
        new MaybeCompressedFileResource(this.fileResource("foo.bz2")).resource instanceof Bzip2Archiver

package org.gradle.api.internal.file.archive;

import org.gradle.api.GradleException;
import org.gradle.api.InvalidUserDataException;
import org.gradle.api.file.EmptyFileVisitor;
import org.gradle.api.internal.file.MaybeCompressedFileResource;
import org.gradle.api.internal.file.TestFiles;
import org.gradle.api.internal.provider.Providers;
import org.gradle.api.resources.internal.LocalResourceAdapter;

                return new LocalResourceAdapter(new LocalFileStandInExternalResource(tarFile, fileSystem));
            }
        });

        TarFileTree tarTree = new TarFileTree(fileProvider, resource.map(MaybeCompressedFileResource::new), fileSystem, directoryFileTreeFactory, fileHasher, decompressionCoordinator, temporaryFileProvider);
        return new FileTreeAdapter(tarTree, taskDependencyFactory, patternSetFactory);
    }