status_snapshot.rb

class StatusSnapshot < ActiveRecord::Base
  attr_accessible :error_message, :failed, :final_json, :processed_yaml, :raw_json, :tree

  #serialize :tree, StatusNode

  def version
    tree.version
  end

  class << self

    def successful
      where(failed: false)
    end

    def latest
      order('updated_at ASC')
    end

    def from_stypi_json(json_string)

      last_snapshot = latest.successful.last
      new_snapshot_hash = JSON.parse(json_string)

      # Only create a new snapshot if there's a newer version.
      if last_snapshot && new_snapshot_hash["version"].to_s == last_snapshot.version.to_s
        return last_snapshot
      end

      # Create the new snapshot
      new_snapshot = new

      new_snapshot.tree = 
        StatusNode.from_stypi_hash(new_snapshot_hash,
                                   last_snapshot && 
                                   JSON.parse(last_snapshot.raw_json))
      new_snapshot
    end
  end

  protected

  # TODO: Hack! FactoryGirl tries to invoke `singleton_method_added=` for some reason?
  #attr_accessor :singleton_method_added if if Rails.env.test?
end

status_snapshot_factory.rb

FactoryGirl.define do
  factory :status_snapshot do
    # Empty factory still causes the error
  end
end