TDD Fizzbuzz

fizzbuzz_test.rb

# multiplo de 3 => Fizz
# multiplo de 5 => Buzz
# multiplo de 5 y de 3 => FizzBuzz
# si no, el mismo número

require 'test/unit'

# Red -> Green -> Refactor ...
#

def fizzbuzz(number)
  return 'FizzBuzz' if is_fizz_buzz(number)
  return 'Buzz' if is_buzz(number)
  return 'Fizz' if is_fizz(number)
  number
end

def is_fizz_buzz(number)
  is_fizz(number) and is_buzz(number)
end

def is_fizz(number)
  number % 3 == 0
end

def is_buzz(number)
  number % 5 == 0
end

class FizzBuzzTest < Test::Unit::TestCase
  def test_returns_fizz_when_number_is_fizz
    assert_equal(fizzbuzz(6), 'Fizz')
  end

  def test_returns_buzz_when_number_is_buzz
    assert_equal(fizzbuzz(20), 'Buzz')
  end

  def test_returns_same_number_when_number_is_not_fizz_nor_buzz
    assert_equal(fizzbuzz(2), 2)
  end

  def test_returns_fizzbuzz_when_number_is_fizz_and_buzz
    assert_equal(fizzbuzz(15), 'FizzBuzz')
  end
end