CrAzYcAsE test extensions

CrazyCaseTestExtensions.cs

using System;
using System.Linq;
using Xunit;

namespace Example.Tests
{
    public static class TestExtensions
    {
        public static string ToCrAzYcAsE(this string input)
            => input
                ?.WithIndex()
                ?.Aggregate("", (acc, i) =>
                    acc + (i.Index % 2 == 0 ?
                        Char.ToUpper(i.Value) :
                        Char.ToLower(i.Value)
                    )
                );
    }

    /// M E T A
    /// E
    /// T
    /// A
    public class TestExtensionsTests
    {
        [Fact]
        public void ToCrAzYcAsE_gIvEnNuLl_ShOuLdReTuRnNuLl()
            => Assert.Null(TestExtensions.ToCrAzYcAsE(null));

        [Theory]
        [InlineData("flatearth")]
        [InlineData("FLATEARTH")]
        [InlineData("flatEARTH")]
        public void ToCrAzYcAsE_sHoUlDcRaZyCaSeThEiNpUt(string input)
            => Assert.Equal("FlAtEaRtH", input.ToCrAzYcAsE());
    }
}