Recursively find all files in a directory and subdirectories

RecursiveFileFindBehaviour.scala

trait RecursiveFileFindBehaviour {
  import java.io.File
  /**
    * Recursively finds all the files in the file system under a given directory
    *
    * @param dir        the directory to find all files in
    * @param filesFound always use Set.empty when calling, used internally for keeping track of discovered files
    * @return A set of files from the specified directory and all subdirectories found in tree
    */
  def findFiles(dir: File, filesFound: Set[File] = Set.empty): Set[File] = {
    val r = dir.listFiles().partition(p => p.isDirectory)
    if (r._1.nonEmpty) r._1.flatMap(findFiles(_, r._2.toSet union filesFound)).toSet else filesFound union r._2.toSet
  }
}