Hash to OpenStruct and vice-versa

conversion.rb

module Conversion
  module Boolean; end
  class TrueClass; include Boolean; end
  class FalseClass; include Boolean; end

  def to_openstruct(hashed_object)
    case hashed_object
    when Hash
      boolean_methods = []
      hashed_object.each do |k, v|
        hashed_object[k] = to_openstruct(v)
        boolean_methods << k if v.is_a?(Boolean) # for boolean methods e.g. :run, :run?
      end
      instance = OpenStruct.new(hashed_object)
      boolean_methods.each { |m| instance.class.send(:define_method, "#{m}?", lambda {hashed_object[m]}) }
      instance
    when Array
      hashed_object.map! { |i| to_openstruct(i) }
    else
      hashed_object
    end
  end

  def to_hash(openstruct_object)
    case openstruct_object
    when Array
      openstruct_object.map! {|i| to_hash(i) }
    when OpenStruct
      hashed_object = {}
      method_names = (openstruct_object.public_methods - OpenStruct.public_instance_methods)
      method_names = method_names.map!(&:to_s).map{|s| s.delete('=')}.uniq
      method_names.each { |m| hashed_object[m.to_sym] = to_hash(openstruct_object.send(m)) }
      hashed_object
    else Object
      openstruct_object
    end
  end
end

conversion_spec.rb

describe Conversion do
  include Conversion

  let(:openstruct_object) do
    OpenStruct.new({
      total: 3,
      content: OpenStruct.new({
        japan: OpenStruct.new({ currency: 'Yen', continent: 'Asia', nuclear_plant: true }),
        england: OpenStruct.new({ currency: 'Sterling', continent: 'Europe', nuclear_plant: true }),
        australia: OpenStruct.new({ currency: 'Australian Dollar', continent: 'Asia Pacific', nuclear_plant: false })
      }),
      car_makers: ['honda', 'jaguar', 'holden']
    })
  end

  let(:hash_object) do
    {
      total: 3,
      content: {
        japan: { currency: 'Yen', continent: 'Asia', nuclear_plant: true },
        england: { currency: 'Sterling', continent: 'Europe', nuclear_plant: true },
        australia: { currency: 'Australian Dollar', continent: 'Asia Pacific', nuclear_plant: false }
      },
      car_makers: ['honda', 'jaguar', 'holden']
    }
  end

  it 'converts openstruct to hash' do
    expect(to_hash(openstruct_object)).to eql(hash_object)
  end

  it 'converts hash to openstruct' do
    expect(to_openstruct(hash_object)).to eql(openstruct_object)
  end
end