generate

# File actionpack/lib/action_dispatch/journey/formatter.rb, line 16
      def generate(name, options, path_parameters, parameterize = nil)
        constraints = path_parameters.merge(options)
        missing_keys = []

        match_route(name, constraints) do |route|
          parameterized_parts = extract_parameterized_parts(route, options, path_parameters, parameterize)

          # Skip this route unless a name has been provided or it is a
          # standard Rails route since we can't determine whether an options
          # hash passed to url_for matches a Rack application or a redirect.
          next unless name || route.dispatcher?

          missing_keys = missing_keys(route, parameterized_parts)
          next unless missing_keys.empty?
          params = options.dup.delete_if do |key, _|
            parameterized_parts.key?(key) || route.defaults.key?(key)
          end

          defaults       = route.defaults
          required_parts = route.required_parts
          parameterized_parts.delete_if do |key, value|
            value.to_s == defaults[key].to_s && !required_parts.include?(key)
          end

          return [route.format(parameterized_parts), params]
        end

        message = "No route matches #{Hash[constraints.sort].inspect}"
        message << " missing required keys: #{missing_keys.sort.inspect}" unless missing_keys.empty?

        raise ActionController::UrlGenerationError, message
      end