BDD in C#

BDD.cs

[TestFixture]
class when_adding_numbers
{
	Maths maths;

	void Given_an_object_in_bigint_mode()
	{
		maths = new Maths();
		maths.BigInt = true;
	}

	[Test]
	public void it_doesnt_overflow_the_size_of_an_int()
	{
		Given_an_object_in_bigint_mode();
		Assert.That(maths.Add(int.MAX, 1), Is.GreaterThan(int.Max));
	}
}

BehavioralNUnit_complex.cs

var spec = new Spec(describe: typeof(Maths));
spec.It["doesn't overflow the size of an int"] = maths.Add(int.MAX, 1).Should() > int.MAX

BehavioralNUnit_simple.cs

maths.Add(int.MAX, 1).Should() > int.MAX;

complex_rspec.rb

describe "Maths#add" do
    before :each do
        @math = Maths.new
    end

    context "when in bigint mode" do
        before :each do
            @math.bigint = true
        end

        it "doesn't overflow the size of an int" do
            @math.add(int.MAX, 1).should > int.MAX
        end
    end
end

FluentAssertion_BDD.cs

maths.Add(int.MAX, 1).Should().BeGreaterThan(int.MAX);

simple_rspec.rb

describe "Maths#add" do
  before :each do
    @math = Maths.new
  end

  it "should add two numbers" do
    @math.add(5, 6).should == 11
  end
end