FizzBuzz TDD implementation

FizzBuzz.rb

module FizzBuzz
  extend self

  def run(n)
    if n % 3 == 0 && n % 5 == 0
      return "FizzBuzz"
    elsif n % 3 == 0
      return "Fizz"
    elsif n % 5 == 0
      return "Buzz"
    else
      return n
    end
  end
end

FizzBuzz_test.rb

require 'minitest/autorun'
require './FizzBuzz'

class FizzBuzzTest < Minitest::Test
  def test_fizzbuzz_run_return_fizz
    expect = "Fizz"
    actual = FizzBuzz.run(6)
    assert_equal expect, actual
  end

  def test_fizzbuzz_run_return_buzz
    expect = "Buzz"
    actual = FizzBuzz.run(10)
    assert_equal expect, actual
  end

  def test_fizzbuzz_run_return_fizzbuzz
    expect = "FizzBuzz"
    actual = FizzBuzz.run(15)
    assert_equal expect, actual
  end

  def test_fizzbuzz_run_return_n
    expect = 8
    actual = FizzBuzz.run(8)
    assert_equal expect, actual
  end
end

Rakefile

require "rake/testtask"

Rake::TestTask.new(:test) do |t|
  t.libs << "test"
  t.test_files = FileList["*_test.rb"]
  t.verbose = true
end

task :default => :test

How to run?

Download this gist as Zip file. Extract to anywhere in your computer.

Run test:

rake

# or

rake test