nested to_json in ruby

nested.rb

# require 'active_support'
# require 'active_support/core_ext'
require 'json'
require 'values'

class Statement < Value.new(:title, :description)
  def to_json(state = nil)
    {
      title: title,
      properties: {
            description: description
      }
    }.to_json(state)
  end

  def self.sample
    with(
      title: 'this is a title',
      description: 'this is a description'
    )
  end
end

class Form < Value.new(:blocks)
  def to_json(state = nil)
    {
      fields: blocks
    }.to_json(state)
  end

  def self.sample
    with(
      blocks: [
        Statement.sample,
        Statement.sample
      ]
    )
  end
end

form = Form.sample
puts form.to_json
# returns: 
# {
#   "fields": [
#     {
#       "title": "this is a title",
#       "properties": {
#         "description": "this is a description"
#       }
#     },
#     {
#       "title": "this is a title",
#       "properties": {
#         "description": "this is a description"
#       }
#     }
#   ]
# }