DocumentDB protocol support for MongoDB

DocumentDb now supports the MongoDB protocol.

I did a test before Christmas using a very slightly modified NEventStore with Mongo persistence routed to DocumentDB. Everything worked fine at the time, now after Christmas something is awry. I wrote a test to isolate the problem and it appears that when persisting a long value (with the expectation it is serialized as an Int64, it is written as an Int32).

I can't figure out what has changed. Perhaps it is my code, or has Microsoft done something "under the hood"?

I tried the code below. The two connection strings alternate between the local "real" Mongo 3.4 server and the DocumentDB with Mongo support in Azure. I added the mongocsharprdriver version 1.10.0 (the one I used before Christmas) and then the very latest and no runtime difference was found.

The code below writes the long as an Int32 in DocumentDb, but as a long in the local MongoDB.

using System;
using System.Linq;
using System.Security.Authentication;
using MongoDB.Bson;
using MongoDB.Driver;
using MongoDB.Driver.Builders;
using MongoDB.Driver.Linq;

namespace DocumentDb.Mongo.Test
{
    internal class Program
    {
        static void Main()
        {
            const string connectionString = @"mongodb://<my Azure MongoDB DocumentDB connection>/?ssl=true&sslverifycertificate=false";
            // const string connectionString = @"mongodb://localhost:27017/test";

            const string indexName = "_id";
            var clientSettings = MongoClientSettings.FromUrl(new MongoUrl(connectionString));
            clientSettings.SslSettings = new SslSettings() { EnabledSslProtocols = SslProtocols.Tls12 };
            var client = new MongoClient(clientSettings);
            var db = client.GetServer().GetDatabase("test");
            var collection = db.GetCollection("testcollection");
  
            const long testValue = 1;
            var doc = new BsonDocument
            {
                {indexName, testValue}
            };

            collection.Update(
                Query.EQ(indexName, testValue),
                Update.Replace(doc),
                UpdateFlags.Upsert);
                
            doc = collection.AsQueryable().First();
            Console.WriteLine($"Value={doc[indexName].AsInt64}");
        }
    }
}