FizzBuzz kata using C# with NUnit and FsCheck

FizzBuzzPropertyTests.cs

using System.Text.RegularExpressions;
using FsCheck;
using FsCheck.Fluent;
using NUnit.Framework;

namespace FizzBuzz
{
    public class FizzBuzzer
    {
        public string Translate(int value)
        {
            var result = string.Empty;
            if (value % 3 == 0) result += "Fizz";
            if (value % 5 == 0) result += "Buzz";
            return string.IsNullOrEmpty(result) ? value.ToString() : result;
        }
    }

    [TestFixture]
    public class FizzBuzzerTests
    {
        private FizzBuzzer _fizzBuzzer;

        private static Gen<int> DivisibleBy(int divisor)
        {
            var divisibleBy =
                from number in Any.OfType<int>()
                where number % divisor == 0
                select number;
            return divisibleBy;
        }

        [SetUp]
        public void BeforeEach()
        {
            _fizzBuzzer = new FizzBuzzer();
        }

        [TestCase(2, Result = "2")]
        [TestCase(3, Result = "Fizz")]
        [TestCase(5, Result = "Buzz")]
        [TestCase(15, Result = "FizzBuzz")]
        public string Given_Value_It_Must_Return_The_Given_Result(int value)
        {
            return _fizzBuzzer.Translate(value);
        }

        [Test]
        public void Given_A_Number_Not_Divisible_By_3_Or_5_It_Must_Return_That_Number()
        {
            var value =
                from number in Any.OfType<int>()
                where number%3 != 0 && number%5 != 0
                select number;

            Spec.For(value, v => _fizzBuzzer.Translate(v).Equals(v.ToString()))
                .QuickCheckThrowOnFailure();
        }

        [TestCase(3, "Fizz")]
        [TestCase(5, "Buzz")]
        [TestCase(15, "FizzBuzz")]
        public void Given_A_Number_Divisible_By_Divisor_It_Must_Contain_Expected(int divisor, string expected)
        {
            Spec.For(DivisibleBy(divisor), d => _fizzBuzzer.Translate(d).Contains(expected))
                .QuickCheckThrowOnFailure();
        }

        [Test]
        public void Given_A_Number_Divisibly_By_3_And_5_It_Must_Contain_Both_Fizz_And_Buzz()
        {
            Spec.For(DivisibleBy(3*5), d => string.IsNullOrEmpty(_fizzBuzzer.Translate(d)) == false)
                .And(d => _fizzBuzzer.Translate(d).Contains("Fizz"))
                .And(d => _fizzBuzzer.Translate(d).Contains("Buzz"))
                .QuickCheckThrowOnFailure();
        }

        [Test]
        public void  Given_A_Number_It_Must_Return_Fizz_Buzz_FizzBuzz_Or_A_Number()
        {
            Spec.ForAny<int>(x => true)
                .Classify(x => _fizzBuzzer.Translate(x).Equals("Fizz"), "Fizz")
                .Classify(x => _fizzBuzzer.Translate(x).Equals("Buzz"), "Buzz")
                .Classify(x => _fizzBuzzer.Translate(x).Equals("FizzBuzz"), "FizzBuzz")
                .Classify(x => Regex.IsMatch(_fizzBuzzer.Translate(x), @"\d+"), "number")
                .QuickCheckThrowOnFailure();
        }
    }
}

See my post which goes with this gist: http://comp-phil.blogspot.com/2014/07/i-have-no-freaking-clue-what-i-am-doing.html