wayback-classic/cgi-bin/lib/error_reporting.rb

require 'json'

module WaybackClassic
  class ErrorReporting
    class ReportableError < StandardError; end

    class ServerError < ReportableError; end

    class BadRequestError < ReportableError; end

    def self.catch_exceptions
      yield
    rescue => error
      unless error.class <= BadRequestError
        STDERR.puts JSON.dump(error: {
                                class: error.class.name,
                                message: error.message,
                                backtrace: error.backtrace
                              },
                              request: {
                                env: ENV.select do |key, value|
                                  key.start_with?("HTTP_", "PATH_", "CONTENT_", "REMOTE_") ||
                                    %w(QUERY_STRING REQUEST_METHOD).include?(key)
                                end
                              })
      end

      error
    end

    def self.catch_and_respond(cgi, &block)
      if error = catch_exceptions(&block)
        status = if error.class <= BadRequestError
                   "BAD_REQUEST"
                 else
                   "SERVER_ERROR"
                 end

        cgi.out "type" => "text/html",
                "charset" => "UTF-8",
                "status" => status do
          render "error.html", error: error
        end
      end
    end
  end
end