オトナな TDD の FizzBuzz Ruby 版 (プロダクションコードとテストコードの合体版)

fizzbuzz_test.rb

# コードとテストコードの合体版 (プロダクションコードとテストコードは分けること)

# プロダクションコード
require 'minitest/autorun'
# require './fizzbuzz'

class FizzBuzz
  def create(a, b)
    res = []
    (a..b).each do |n|
      if n % 3 == 0 and n % 5 == 0
        res << 'FizzBuzz'
      elsif n % 3 == 0
        res << 'Fizz'
      elsif n % 5 == 0
        res << 'Buzz'
      else
        res << n
      end
    end
    res
  end
end

# テストコード
class FizzBuzzTest < Minitest::Test
  def test_running
    assert(true)
  end

  def test_Fizz
    res = FizzBuzz.new.create(1, 10)
    assert_equal(res.length, 10)
    val = 1
    (0..9).each do |n|
       if n == 2
         assert_equal(res[n], 'Fizz')
       elsif n == 5
         assert_equal(res[n], 'Fizz')
       elsif n == 8
         assert_equal(res[n], 'Fizz')
       end
       val += 1
    end
  end

  def test_Buzz
    res = FizzBuzz.new.create(1, 10)
    assert_equal(res.length, 10)
    val = 1
    (0..9).each do |n|
       if n == 4
         assert_equal(res[n], 'Buzz')
       elsif n == 9
         assert_equal(res[n], 'Buzz')
       end
       val += 1
    end
  end

  def test_FizzBuzz
    res = FizzBuzz.new.create(1, 30)
    assert_equal(res.length, 30)
    val = 1
    (0..29).each do |n|
       if n == 14
         assert_equal(res[n], 'FizzBuzz')
       elsif n == 29
         assert_equal(res[n], 'FizzBuzz')
       end
       val += 1
    end
  end
end

$ ruby --version
ruby 2.5.0p0 (2017-12-25 revision 61468) [x86_64-darwin15]
$ ruby fizzbuzz_test.rb
Run options: --seed 53475

# Running:

....

Finished in 0.001612s, 2482.0810 runs/s, 6825.7226 assertions/s.

4 runs, 11 assertions, 0 failures, 0 errors, 0 skips