dotnet 6 test

IEnumerableExtensionsTest.cs

namespace MyExtensions.Test;

public static class IEnumerableExtensions
{
    public static double Median(this IEnumerable<double>? source)
    {
        if (source == null) throw new ArgumentNullException(nameof(source));

        List<double> elements = source.OrderBy(x => x).ToList();

        if (!elements.Any()) throw new InvalidOperationException();

        int count = elements.Count;

        if (count % 2 != 0) return elements[count / 2];

        return (elements[count / 2 - 1] + elements[count / 2]) / 2;
    }
}

public class IEnumerableExtensionsTest
{
    [Fact]
    public void Get_Even_Median()
    {
        List<double> values = new() { 1, 2 };
        double actual = values.Median();

        Assert.Equal(1.5, actual);
    }

    [Fact]
    public void Get_Odd_Median()
    {
        List<double> values = new() { 1, 2, 3 };
        double actual = values.Median();

        Assert.Equal(2, actual);
    }

    [Fact]
    public void Get_Null_Median()
    {
        ArgumentException e = Assert.Throws<ArgumentNullException>(() => IEnumerableExtensions.Median(null));
        Assert.Equal("Value cannot be null. (Parameter 'source')", e.Message);
    }

    [Fact]
    public void Get_Empty_Median()
    {
        Assert.Throws<InvalidOperationException>(() => new List<double>().Median());
    }
}