Comparing dynamic objects in C#

Question

What is the best way to compare two arbitrary dynamic objects for equality? For example these two objects.

I.e.

dynamic obj1 = new ExpandoObject();
obj1.Name = "Marcus";
obj1.Age = 39;
obj1.LengthInMeters = 1.96;

dynamic obj2 = AMethodReturningADynamic();
obj2.Name = "Marcus";
obj2.Age = 39;
obj2.LengthInMeters = 1.96;

Assert.AreEqual(obj1, obj2); // ?

Or is there a way to get the actual properties and their values as lists? To create an ExpandoObject from a dynamic type for example?

Answer 1

ExpandoObject implements ICollection<KeyValuePair<string, object>> (in addition to IDictionary and IEnumerable of the same), so you should be able to compare them property by property pretty easily:

public static bool AreExpandosEquals(ExpandoObject obj1, ExpandoObject obj2)
{
    var obj1AsColl = (ICollection<KeyValuePair<string,object>>)obj1;
    var obj2AsDict = (IDictionary<string,object>)obj2;

    // Make sure they have the same number of properties
    if (obj1AsColl.Count != obj2AsDict.Count)
        return false;

    foreach (var pair in obj1AsColl)
    {
        // Try to get the same-named property from obj2
        object o;
        if (!obj2AsDict.TryGetValue(pair.Key, out o))
            return false;

        // Property names match, what about the values they store?
        if (!object.Equals(o, pair.Value))
            return false;
    }

    // Everything matches
    return true;
}