class Importmap::Map

def expand_directories_into(paths)
  @directories.values.each do |mapping|
    if (absolute_path = absolute_root_of(mapping.dir)).exist?
      find_javascript_files_in_tree(absolute_path).each do |filename|
        module_filename = filename.relative_path_from(absolute_path)
        module_name     = module_name_from(module_filename, mapping)
        module_path     = module_path_from(module_filename, mapping)
        paths[module_name] = MappedFile.new(name: module_name, path: module_path, preload: mapping.preload)
      end
    end
  end
end