module ActionView::PathRegistry

def self.cast_file_system_resolvers(paths)
  paths = Array(paths)
  @file_system_resolver_mutex.synchronize do
    built_resolver = false
    paths = paths.map do |path|
      case path
      when String, Pathname
        path = File.expand_path(path)
        @file_system_resolvers[path] ||=
          begin
            built_resolver = true
            FileSystemResolver.new(path)
          end
      else
        path
      end
    end
    file_system_resolver_hooks.each(&:call) if built_resolver
  end
  paths
end