class Rack::Static

def applicable_rules(path)
  @header_rules.find_all do |rule, new_headers|
    case rule
    when :all
      true
    when :fonts
      /\.(?:ttf|otf|eot|woff2|woff|svg)\z/.match?(path)
    when String
      path = ::Rack::Utils.unescape(path)
      path.start_with?(rule) || path.start_with?('/' + rule)
    when Array
      /\.(#{rule.join('|')})\z/.match?(path)
    when Regexp
      rule.match?(path)
    else
      false
    end
  end
end