Scala Zip with Cats and FS2

ZipHelper.scala

object ZipUtil {

  import cats.effect.{IO, Resource}
  import cats.implicits.*
  import fs2.io.{readInputStream, writeOutputStream}
  import java.io.{File, FileInputStream, FileOutputStream}
  import java.util.zip.{ZipEntry, ZipOutputStream}

  private val bufferSize = 8192

  def zipFiles(sources: Set[String], dest: String): IO[String] =
    zipOutputStreamResource(dest).use { zipOut =>
      sources.map(new File(_)).toList.traverse_(addFileToZip(zipOut, ""))
    }.as(dest)

  def zipFile(source: String, dest: String): IO[String] =
    zipFiles(Set(source), dest).as(dest)

  private def zipOutputStreamResource(path: String): Resource[IO, ZipOutputStream] =
    Resource
      .make(IO(new FileOutputStream(path))) { fos =>
        IO(fos.close())
      }
      .flatMap { fos =>
        Resource.make(IO(new ZipOutputStream(fos))) { zos =>
          IO(zos.close())
        }
      }

  private def addFileToZip(zipOut: ZipOutputStream, parentPath: String)(file: File): IO[Unit] = {
    val entryName = if (parentPath.isEmpty) file.getName else s"$parentPath/${file.getName}"

    if (file.isDirectory) {
      val dirEntryName = if (entryName.endsWith("/")) entryName else s"$entryName/"
      IO(zipOut.putNextEntry(new ZipEntry(dirEntryName))) *>
        IO(zipOut.closeEntry()) *>
        IO(Option(file.listFiles()).getOrElse(Array.empty[File]).toList)
          .flatMap(_.traverse_(addFileToZip(zipOut, dirEntryName)))
    } else {
      val entry = new ZipEntry(entryName)
      for {
        _ <- IO(zipOut.putNextEntry(entry))
        _ <- copyFileToZip(zipOut)(file)
        _ <- IO(zipOut.closeEntry())
      } yield ()
    }
  }

  private def copyFileToZip(zipOut: ZipOutputStream)(file: File): IO[Unit] = {
    val inputStreamResource: Resource[IO, FileInputStream] =
      Resource.make(IO(new FileInputStream(file))) { fis =>
        IO(fis.close())
      }

    inputStreamResource.use { fis =>
      readInputStream(IO(fis), chunkSize = bufferSize)
        .through(writeOutputStream(IO(zipOut), closeAfterUse = false))
        .compile
        .drain
    }
  }
}