migrations run repeatly about mongodb.entities

[dj-nitehawk]

tried to replicate the issue with the following code:

using MongoDB.Entities;

await DB.InitAsync("test", "localhost");

await DB.MigrateAsync<_001_first_migration>();

Console.ReadLine();

public class _001_first_migration : IMigration
{
    public Task UpgradeAsync()
    {
        Console.Write("migration one complete!" + Environment.NewLine);
        return Task.CompletedTask;
    }
}

public class _002_second_migration : IMigration
{
    public Task UpgradeAsync()
    {
        Console.Write("migration two complete!" + Environment.NewLine);
        return Task.CompletedTask;
    }
}

but it's working correctly. only see the console messages during the first app run. subsequent runs do not print the messages and the migrations are not executed. and the migration history collection in the db has these:

[
  {
	  "_id" : ObjectId("6492d9b9102a0f2720ea2fe8"),
	  "Number" : 2,
	  "Name" : "second migration",
	  "TimeTakenSeconds" : 0.0001599
  },
  {
	  "_id" : ObjectId("6492d9b9102a0f2720ea2fe7"),
	  "Number" : 1,
	  "Name" : "first migration",
	  "TimeTakenSeconds" : 0.0015929
  }
]

send me a self contained repro project that i can debug with a local mongo instance, and i'll look in to it further.

[li-zheng-hao]

i found this problem is related with mongodb server version (4.2.6). if i use 4.4.19 version of mongodb server, everything is ok .

reproduce steps:

1. using docker: docker run --name mongodb -p 27017:27017 -d mongo:4.2.6 or install mongodb server with same version
2. run below code more than one time

using MongoDB.Entities;

await DB.InitAsync("testdb");

var lastMigNum = await
    DB.Find<Migration, int>()
        .Sort(m => m.Number, Order.Descending)
        .Project(m => m.Number)
        .ExecuteFirstAsync();

// always 0
Console.WriteLine(lastMigNum);

await DB.MigrateAsync<_0001_Migration_20221103>();

public class _0001_Migration_20221103:IMigration
{
    public async Task UpgradeAsync()
    {
        try
        {
            Console.WriteLine("migration success");
        }
        catch (Exception e)
        {
            Console.WriteLine(e.Message);
        }
    }
}

[dj-nitehawk]

yeah mongo minimum version should be 4.4 with the current driver afaik.