MongoHelper.cs

public static bool SameAs(this BsonDocument source, BsonDocument other, params string[] ignoreFields)
{
    var elements = source.Elements.Where(x => !ignoreFields.Contains(x.Name)).ToArray();
    if (elements.Length == 0 && other.Elements.Where(x => !ignoreFields.Contains(x.Name)).Any()) return false;
    foreach (var element in source.Elements)
    {
        if (ignoreFields.Contains(element.Name)) continue;
        if (!other.Names.Contains(element.Name)) return false;
        var value = element.Value;
        var otherValue = other[element.Name];
        if (!value.SameAs(otherValue)) return false;
    }
    return true;
}

public static bool SameAs(this BsonValue value, BsonValue otherValue)
{
    if (value.IsBsonDocument)
    {
        if (!otherValue.IsBsonDocument) return false;
        if (!value.AsBsonDocument.SameAs(otherValue.AsBsonDocument)) return false;
    }
    else if (value.IsBsonArray)
    {
        if (!otherValue.IsBsonArray) return false;
        if (value.AsBsonArray.Count != otherValue.AsBsonArray.Count) return false;
        var array = value.AsBsonArray.OrderBy(x => x).ToArray();
        var otherArray = otherValue.AsBsonArray.OrderBy(x => x).ToArray();
        return !array.Where((t, i) => !t.SameAs(otherArray[i])).Any();
    }
    else return value.Equals(otherValue);
    return true;
}