class CodeStatistics

def calculate_directory_statistics(directory, pattern = /^(?!\.).*?\.(rb|js|ts|css|scss|coffee|rake|erb)$/)
  stats = CodeStatisticsCalculator.new
  Dir.foreach(directory) do |file_name|
    path = "#{directory}/#{file_name}"
    if File.directory?(path) && !file_name.start_with?(".")
      stats.add(calculate_directory_statistics(path, pattern))
    elsif file_name&.match?(pattern)
      stats.add_by_file_path(path)
    end
  end
  stats
end