test_zenra.rb

# coding: utf-8

require 'test/unit'
require File.join(File.dirname(File.expand_path(__FILE__)), '..', 'lib', 'zenra')

class ZenraTest < Test::Unit::TestCase

  def setup
    @appid = ENV['YAHOO_APPID']
  end

  def test_zenrize_verb
    zenra = Zenra.new(@appid)
    assert_equal('お腹が全裸で空きました',
                 zenra.zenrize('お腹が空きました'))
  end

  def test_zenrize_noun
    zenra = Zenra.new(@appid, '名詞', '夜の')
    assert_equal('夜のお腹が空いたので夜のスパゲッティが食べたい',
                 zenra.zenrize('お腹が空いたのでスパゲッティが食べたい'))
  end

end

zenra.rb

# coding: utf-8

require 'open-uri'
require 'rexml/document'

class Zenra

  def initialize(appid, position='動詞', text='全裸で', base_url='http://jlp.yahooapis.jp/MAService/V1/parse')
    @appid    = appid
    @position = position
    @text     = text
    @base_url = base_url
  end

  def zenrize(sentence)
    raise "appid is necessary!" if @appid.nil? || @appid.empty?
    raise "Japanese sentence is necessary!" if sentence.nil? || sentence.empty?

    req = "#{@base_url}?results=ma&appid=#{@appid}&sentence=#{URI.encode(sentence)}"
    res = open(req)
    xml = REXML::Document.new(res.read)

    return sentence if xml.elements['ResultSet/ma_result/total_count'].text == '0'

    result = ''
    xml.elements.each('ResultSet/ma_result/word_list/word') do |e|
      result << @text if e.elements['pos'].text == @position
      result << e.elements['surface'].text
    end
    result
  end

end