Unit test with custom class objects

parser.rb

def parse_sentence(word_list)
  puts "First state of the array"
  p word_list
  subj = parse_subject(word_list)
  puts "First shift getting the subject, if no subject, player goes default"
  p word_list
  verb = parse_verb(word_list)
  puts "Second shift getting the verb."
  p word_list
  obj = parse_object(word_list)
  puts "Third shift deleting the stop words, and getting the object for sentence"
  p word_list
    
  Sentence.new(subj,verb,obj)
end

p x = parse_sentence([['noun','jorge'],['verb','eats'],['stop','a'],['noun','sandwich']])

sentence.rb

class Sentence
  attr_accessor :subject, :verb, :obj
  
  def initialize(subject, verb, obj)
    @subject = subject[1]
    @verb = verb[1]
    @obj = obj[1]
  end
  
  def ==(another_sentence)
   if self.subject == another_sentence.subject && self.verb == another_sentence.verb && self.obj == another_sentence.obj
     true
   end
  end
end

test_parser.rb

require 'EX48/parser.rb'
require 'EX48/sentence.rb'
require 'test/unit'

class TestParser < Test::Unit::TestCase

#parse_sentence must return a #Sentence object like
#<Sentence:0x000000033dc450 @obj="sandwich", @subject="jorge", @verb="eats">
  
  def test_good_sentences()
    assert_equal(parse_sentence([['noun','jorge'],['verb','eats'],['stop','a'],['noun','sandwich']]),Sentence.new('jorge','eats','sandwich'))
  end
end