Proving FizzBuzz traits in C# using SpecFlow with NUnit.

FizzBuzzer.cs

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;
        }
    }
}

FizzBuzzerSpec.feature

Feature: FizzBuzzerSpec
    I want to be able to translate numbers to their FizzBuzz value
	In order to be able to communicate with the FizzBuzzons
	As a Starfleet Captain
 
Scenario: 2 must translate to the string 2
	Given a FizzBuzzer
	And the value of '2'
	When translate is invoked
	Then the result should be '2'
 
Scenario: 3 must translate to the string Fizz
	Given a FizzBuzzer
	And the value of '3'
	When translate is invoked
	Then the result should be 'Fizz'
 
Scenario: 5 must translate to the string Buzz
	Given a FizzBuzzer
	And the value of '5'
	When translate is invoked
	Then the result should be 'Buzz'
 
Scenario: 15 must translate to the string FizzBuzz
	Given a FizzBuzzer
	And the value of '15'
	When translate is invoked
	Then the result should be 'FizzBuzz'
 
Scenario Outline: FizzBuzz translation
	Given a FizzBuzzer
	And the value of '<value>'
	When translate is invoked
	Then the result should be '<expected value>'
 
	Examples: 
	| value | expected value |
	| 2     | 2              |
	| 4     | 4              |
	| 3     | Fizz           |
	| 9     | Fizz           |
	| 5     | Buzz           |
	| 25    | Buzz           |
	| 15    | FizzBuzz       |
	| 30    | FizzBuzz       |

FizzBuzzerSpecSteps.cs

using FizzBuzz;
using TechTalk.SpecFlow;
using NUnit.Framework;
 
namespace FizzBuzzSpec
{
    [Binding]
    public class FizzBuzzerSpecSteps
    {
        [Given(@"a FizzBuzzer")]
        public void GivenAFizzBuzzer()
        {
            ScenarioContext.Current.Add("FizzBuzzer", new FizzBuzzer());
        }
 
        [Given(@"the value of '(.*)'")]
        public void GivenTheValueOf(int value)
        {
            ScenarioContext.Current.Add("value", value);
        }
 
        [When(@"translate is invoked")]
        public void WhenTranslateIsInvoked()
        {
            var fizzbuzzer = ScenarioContext.Current.Get<FizzBuzzer>("FizzBuzzer");
            var value = ScenarioContext.Current.Get<int>("value");
 
            ScenarioContext.Current.Add("actual", fizzbuzzer.Translate(value));
        }
 
        [Then(@"the result should be '(.*)'")]
        public void ThenTheResultShouldBe(string expected)
        {
            var actual = ScenarioContext.Current.Get<string>("actual");
            Assert.That(expected, Is.EqualTo(actual));
        }
    }
}

See my blog post which goes with this gist: http://comp-phil.blogspot.com/2014/06/proving-traits.html