gistfile1.txt

require "dump/version"

module Dump
  class Error < StandardError; end
  
  class InstanceVar
    attr_reader :name
    attr_reader :obj

    def initialize(name, obj, parent)
      @name = name
      @obj = obj
      @parent = parent
    end

    def to_s
      "#{@name} - #{obj.class}"
    end

    def history
      (@parent.nil? ? [] : @parent.history) + [to_s]
    end
  end

  class Diver
    def initialize(base_obj)
      @base_obj = base_obj
    end
    
    def dive
      to_investigate = [InstanceVar.new('Root', @base_obj, nil)]
      max_to_check = 10000
      checked = 0

      while (var = to_investigate.shift)
        checked += 1 
        if checked > max_to_check
          return "Limiting Checks (max = #{max_to_check})"
        end

        obj = var.obj

        if offending_hash?(obj)
          return "Found undumpable object: #{var.history}"
        end

        if !dumps?(obj)
          if obj.is_a? Hash
            keys = obj.keys
            keys.each do |key|
              to_investigate.push(
                InstanceVar.new(key.to_s, obj[key], var)
              )
            end
          else
            symbols = obj.instance_variables
            if !symbols.any?
              return "Found undumpable object: #{var.history}"
            end

            symbols.each do |sym|
              to_investigate.push(
                InstanceVar.new(sym, obj.instance_variable_get(sym), var)
              )
            end
          end
        end
      end

      true
    end

    def dumps?(obj)
      Marshal.dump(obj)
      true
    rescue TypeError
      false
    end

    def offending_hash?(obj)
      obj.is_a?(Hash) && !obj.default_proc.nil?
    end
  end
end