calculate_directory_statistics

# File railties/lib/rails/code_statistics.rb, line 43
    def calculate_directory_statistics(directory, pattern = /^(?!\.).*?\.(rb|js|ts|coffee|rake)$/)
      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