normalize_filter

# File actionpack/lib/action_dispatch/routing/inspector.rb, line 97
        def normalize_filter(filter)
          if filter[:controller]
            { controller: /#{filter[:controller].underscore.sub(/_?controller\z/, "")}/ }
          elsif filter[:grep]
            grep_pattern = Regexp.new(filter[:grep])
            path = URI::DEFAULT_PARSER.escape(filter[:grep])
            normalized_path = ("/" + path).squeeze("/")

            {
              controller: grep_pattern,
              action: grep_pattern,
              verb: grep_pattern,
              name: grep_pattern,
              path: grep_pattern,
              exact_path_match: normalized_path,
            }
          end
        end