Hash to Dotted Path

hash_to_dotted_path.rb

class HashToDottedPath
  def initialize(hash)
    @hash = hash
  end

  def to_dotted_path
    result = []
    @hash.each do |k, v|
      explore_keys(v, [k], result)
    end
    result.map! { |e| [e[0..-2].join('.'), e[-1]] }.to_h
  end

  private

  def explore_keys(hash, state, list)
    hash.each do |k, v|
      s = state.dup
      if v.is_a?(Hash)
        s << k
        explore_keys(v, s, list)
      else
        s << k << v
        list << s
      end
    end
  end
end