using NUnit.Framework;

​

public class FizzBuzz

{

    public static void Main() { }

    public string FizzyOutput(int input)

    {

        if (input % 15 == 0)

            return "FizzBuzz";

        if (input % 3 == 0)

            return "Fizz";

        if (input % 5 == 0)

            return "Buzz";

        return input.ToString();

    }

}

​

[TestFixture]

public class FizzBuzzTests

{

    private FizzBuzz fizzBuzz;

    [SetUp]

    public void Setup()

    {

        fizzBuzz = new FizzBuzz();

    }

    [Test]

    public void FizzyOutput_OutputsOne_WhenInputIsOne()

    {

        var output = fizzBuzz.FizzyOutput(1);

        Assert.AreEqual("1", output);

    }

    [Test]

    public void FizzyOutput_OutputsTwo_WhenInputIsTwo()

    {

        var output = fizzBuzz.FizzyOutput(2);

        Assert.AreEqual("2", output);

    }

    [TestCase(3)]

    [TestCase(6)]

    [TestCase(9)]

    public void FizzyOutput_OutputsFizz_WhenInputIsMultipleOfThree(int input)

    {

        var output = fizzBuzz.FizzyOutput(input);

        Assert.AreEqual("Fizz", output);

    }

    [TestCase(5)]

    [TestCase(10)]

    public void FizzyOutput_OutputsBuzz_WhenInputIsMultipleOfFive(int input)

    {

        var output = fizzBuzz.FizzyOutput(input);

        Assert.AreEqual("Buzz", output);

    }

    [TestCase(15)]

    [TestCase(30)]

    [TestCase(45)]

    public void FizzyOutput_OutputsFizzBuzz_WhenInputIsMultipleOfThreeAndFive(int input)

    {

        var output = fizzBuzz.FizzyOutput(input);

        Assert.AreEqual("FizzBuzz", output);

    }

    [TestCase(1, "1")]

    [TestCase(2, "2")]

    [TestCase(3, "Fizz")]

    [TestCase(4, "4")]

    [TestCase(5, "Buzz")]

    // ....

    [TestCase(14, "14")]

    [TestCase(15, "FizzBuzz")]

    [TestCase(16, "16")]

    // ...

    [TestCase(95, "Buzz")]

    [TestCase(96, "Fizz")]

    [TestCase(97, "97")]

    [TestCase(98, "98")]

    [TestCase(99, "Fizz")]

    [TestCase(100, "Buzz")]

    public void FizzyOutput_OutputsExpectedValues(int input, string expectedOutput)

    {

        var actualOutput = fizzBuzz.FizzyOutput(input);

        Assert.AreEqual(expectedOutput, actualOutput);

    }

}

​