Question

Take the following class and unit test.

public class Entity
    {
        public object Id { get; set; }

        public override bool Equals(object obj)
        {
            return this == (Entity)obj;
        }

        public static bool operator == (Entity base1, Entity base2)
        {
            if (base1.Id != base2.Id)
            {
                return false;
            }

            return true;
        }

        public static bool operator != (Entity base1, Entity base2)
        {
            return (!(base1.Id == base2.Id));
        }
    }

---

        [TestMethod]
        public void Test()
        {
            Entity e1 = new Entity { Id = 1 };
            Entity e2 = new Entity { Id = 1 };
            Assert.IsTrue(e1 == e2); //Always fails
        }

Can someone explain why its fails?

Answer 1

Because you are relying on an object reference for comparator:

public object Id { get; set; }

Replace

    public static bool operator == (Entity base1, Entity base2)
    {
        if (base1.Id != base2.Id)
        {
            return false;
        }

        return true;
    }

With

    public static bool operator == (Entity base1, Entity base2)
    {
        return object.Equals(base1.Id, base2.Id);
    }