tdd2.rb

require "test/unit"
class ArabicGenerator 
   TABLE = {
      "I" => 1,
      "V" => 5
    }

   def convert(roman_number)
     arabic_num = 0
     char = roman_number.split("")
     char.each_with_index do |c, i|
     		if TABLE[char[i + 1]] == nil
     			arabic_num += TABLE[c]
     		elsif TABLE[char[i + 1]] > TABLE[c]
         	return arabic_num += (TABLE[char[i + 1]] - TABLE[c])
        else 
           arabic_num += TABLE[c]
        end
     end
     return arabic_num 
   end
   
end
class ArabicGeneratorTest < Test::Unit::TestCase
   def setup
      @converter = ArabicGenerator.new
   end
   def test_return_1
      assert_equal 1, @converter.convert("I")
   end
   def test_return_2
      assert_equal 2, @converter.convert("II")
   end
   def test_return_3
      assert_equal 3, @converter.convert("III")
   end
   def test_return_4
      assert_equal 4, @converter.convert("IV")
   end
end