mgo driver: Remove the last remaining use of mgocompat

datagen/mongo_connection.go

@@ -10,7 +10,6 @@ import (
 	"time"
 
 	"go.mongodb.org/mongo-driver/bson"
-	"go.mongodb.org/mongo-driver/bson/mgocompat"
 	"go.mongodb.org/mongo-driver/mongo"
 	"go.mongodb.org/mongo-driver/mongo/options"
 	"go.mongodb.org/mongo-driver/mongo/readpref"
@@ -108,16 +107,3 @@ func createClientOptions(conn *Connection) *options.ClientOptions {
 
 	return connOpts.SetAuth(credentials)
 }
-
-func runMgoCompatCommand(ctx context.Context, session *mongo.Client, db string, cmd any) error {
-	// With the default registry, index.Collation is kept event when it's empty,
-	// and it make the command fail
-	// to fix this, marshal the command to a bson.Raw with the mgocompat registry
-	// providing the same behavior that the old mgo driver
-	mgoRegistry := mgocompat.NewRespectNilValuesRegistryBuilder().Build()
-	_, cmdBytes, err := bson.MarshalValueWithRegistry(mgoRegistry, cmd)
-	if err != nil {
-		return fmt.Errorf("fait to generate mgocompat command\n  cause: %v", err)
-	}
-	return session.Database(db).RunCommand(ctx, cmdBytes).Err()
-}

datagen/mongo_writer.go

@@ -193,7 +193,11 @@ func (w *mongoWriter) createCollection(coll *Collection) error {
 		// as the collection is empty, no need to create the indexes on the sharded key before creating the collection,
 		// because it will be created automatically by mongodb. See https://docs.mongodb.com/manual/core/sharding-shard-key/#shard-key-indexes
 		// for details
-		err = runMgoCompatCommand(context.Background(), w.session, "admin", coll.ShardConfig)
+		cmdBytes, err := bson.Marshal(coll.ShardConfig)
+		if err != nil {
+			return fmt.Errorf("fait to marshal sharding cmd\n  cause: %v", err)
+		}
+		err = w.session.Database("admin").RunCommand(context.Background(), cmdBytes).Err()
 		if err != nil {
 			return fmt.Errorf("fail to shard collection '%s' in db '%s'\n  cause: %v", coll.Name, coll.DB, err)
 		}