Attempt to validate behavior of IsOverridden implementation suggested by http://stackoverflow.com/a/10020948/150

IsOverrideTests.cs

using System.Reflection;
using NUnit.Framework;

public class IsOverrideTests
{
    abstract class Base
    {
        public virtual void Overridden() { }
        public virtual void Inherited() { }
    }

    class Derived : Base
    {
        public override void Overridden() { }
    }

    /// <summary>broken</summary>
    public static bool IsOverride_broken(MethodInfo m)
    {
        return m.GetBaseDefinition() != m;
    }

    [Test]
    public void IsOverride_broken_overriden()
    {
        Assert.IsTrue(IsOverride_broken(
            typeof (Derived).GetMethod("Overridden")));
    }

    [Test]
    public void IsOverride_broken_inherited()
    {
        Assert.IsFalse(IsOverride_broken(
            typeof(Derived).GetMethod("Inherited")));
    }

    /// <summary>not as broken</summary>
    public static bool IsOverride_better(MethodInfo m)
    {
        return m.GetBaseDefinition().DeclaringType != m.DeclaringType;
    }

    [Test]
    public void IsOverride_better_overriden()
    {
        Assert.IsTrue(IsOverride_better(
            typeof(Derived).GetMethod("Overridden")));
    }

    [Test]
    public void IsOverride_better_inherited()
    {
        Assert.IsFalse(IsOverride_better(
            typeof(Derived).GetMethod("Inherited")));
    }
}