module Roda::RodaPlugins::Json::RequestMethods

def convert_to_json(obj)

but can use a custom serializer passed to the plugin.
Convert the given object to JSON. Uses to_json by default,
def convert_to_json(obj)
  args = [obj]
  args << self if roda_class.opts[:json_result_include_request]
  roda_class.opts[:json_result_serializer].call(*args)
end