NServiceBus 6 SQL Transport Multi-Instance mode support for connection strings in app.config with legacy 'queue schema' argument

SqlServerTransportConfigurationExtensions.cs

using System;
using System.Collections.Generic;
using System.Configuration;
using System.Data.Common;
using System.Data.SqlClient;

namespace NServiceBus
{
    using Transport.SQLServer;

    public static class SqlServerTransportConfigurationExtensions
    {
        const string DefaultConnectionString = "NServiceBus/Transport";
        const string Prefix = "NServiceBus/SqlTransport/LegacyMultiInstance/"; // Previously `NServiceBus/Transport/*`

        public static void ConfigureConfigurationStrings(this TransportExtensions<SqlServerTransport> transport)
        {

            var item = ConfigurationManager.ConnectionStrings[DefaultConnectionString];
            if (item == null) throw new Exception($"Connection string '{DefaultConnectionString}' not set.");
            var defaultConnectionString = item.ConnectionString;

            var values = new Dictionary<string, string>();

            foreach (ConnectionStringSettings i in ConfigurationManager.ConnectionStrings)
            {
                var QueueSchemaKey = "Queue Schema";

                if (!i.Name.StartsWith(Prefix)) continue;

                var queueName = i.Name.Substring(Prefix.Length);

                var b = new DbConnectionStringBuilder { ConnectionString = i.ConnectionString };

                if (b.ContainsKey(QueueSchemaKey))
                {
                    transport.UseSchemaForEndpoint(endpointName: queueName, schema: (string)b[QueueSchemaKey]);
                    transport.UseSchemaForQueue(queueName: queueName, schema: (string)b[QueueSchemaKey]);
                    b.Remove(QueueSchemaKey);
                }

                values[queueName] = b.ToString();
            }

            transport.EnableLegacyMultiInstanceMode(async address =>
            {
                var connectionString = values.ContainsKey(address)
                    ? values[address]
                    : defaultConnectionString;
                var connection = new SqlConnection(connectionString);
                await connection.OpenAsync().ConfigureAwait(false);
                return connection;
            });
        }
    }
}