class Rspec::Core::Configuration

def files_to_run=(*files)
  files.flatten!
  result = []
  files.each do |file|
    if File.directory?(file)
      filename_pattern.split(",").each do |pattern|
        result += Dir[File.expand_path("#{file}/#{pattern.strip}")]
      end
    elsif File.file?(file)
      result << file
    else
      raise "File or directory not found: #{file}"
    end
  end
  options[:files_to_run] = result
end