docx unique word count

gistfile1.rb

#!/usr/bin/ruby

require 'zip'
require 'nokogiri'

class Docx
  def self.word_count(file, zip=Zip::ZipFile.open(file))
    Nokogiri::XML.parse(zip.find_entry("word/document.xml").get_input_stream).text.split(" ").uniq.length
  end
end

puts Docx.word_count("sample.docx")