rails--rails/activesupport/lib/active_support/json/encoding.rb

module ActiveSupport
  module JSON
    class CircularReferenceError < StandardError
    end

    # Converts a Ruby object into a JSON string.
    def self.encode(value, options = nil, seen = nil)
      seen ||= []
      if seen.any? { |object| object.equal?(value) }
        raise CircularReferenceError, 'object references itself'
      end
      seen << value
      value.__send__(:rails_to_json, options, seen)
    ensure
      seen.pop
    end
  end
end

require 'active_support/json/variable'
require 'active_support/json/encoders/date'
require 'active_support/json/encoders/date_time'
require 'active_support/json/encoders/enumerable'
require 'active_support/json/encoders/false_class'
require 'active_support/json/encoders/hash'
require 'active_support/json/encoders/nil_class'
require 'active_support/json/encoders/numeric'
require 'active_support/json/encoders/object'
require 'active_support/json/encoders/regexp'
require 'active_support/json/encoders/string'
require 'active_support/json/encoders/symbol'
require 'active_support/json/encoders/time'
require 'active_support/json/encoders/true_class'