Small clean up and refactoring

Author: bahusoid

src/NHibernate.Test/Async/MultiTenancy/DatabaseStrategyNoDbSpecificFixture.cs

@@ -165,7 +165,7 @@ private ISession OpenTenantSession(string tenantId)
 
 		private TenantConfiguration GetTenantConfig(string tenantId)
 		{
-			return new TenantConfiguration(new TestTenantConnectionProvider(Sfi, tenantId));
+			return new TenantConfiguration(new TestTenantConnectionProvider(Sfi, tenantId, IsSqlServerDialect));
 		}
 
 		private bool IsSqlServerDialect => Sfi.Dialect is MsSql2000Dialect && !(Sfi.ConnectionProvider.Driver is OdbcDriver);

src/NHibernate.Test/MultiTenancy/DatabaseStrategyNoDbSpecificFixture.cs

@@ -185,7 +185,7 @@ private ISession OpenTenantSession(string tenantId)
 
 		private TenantConfiguration GetTenantConfig(string tenantId)
 		{
-			return new TenantConfiguration(new TestTenantConnectionProvider(Sfi, tenantId));
+			return new TenantConfiguration(new TestTenantConnectionProvider(Sfi, tenantId, IsSqlServerDialect));
 		}
 
 		private bool IsSqlServerDialect => Sfi.Dialect is MsSql2000Dialect && !(Sfi.ConnectionProvider.Driver is OdbcDriver);
@@ -271,12 +271,12 @@ public IConnectionAccess GetConnectionAccess()
 	[Serializable]
 	public class TestTenantConnectionProvider : AbstractMultiTenantConnectionProvider
 	{
-		public TestTenantConnectionProvider(ISessionFactoryImplementor sfi, string tenantId)
+		public TestTenantConnectionProvider(ISessionFactoryImplementor sfi, string tenantId, bool isSqlServerDialect)
 		{
 			TenantIdentifier = tenantId;
 			SessionFactory = sfi;
 			TenantConnectionString = sfi.ConnectionProvider.GetConnectionString();
-			if (sfi.Dialect is MsSql2005Dialect)
+			if (isSqlServerDialect)
 			{
 				var stringBuilder = new SqlConnectionStringBuilder(sfi.ConnectionProvider.GetConnectionString());
 				stringBuilder.ApplicationName = tenantId;

src/NHibernate/Cache/CacheKey.cs

@@ -43,6 +43,7 @@ public CacheKey(object id, IType type, string entityOrRoleName, ISessionFactoryI
 			_hashCode = GenerateHashCode();
 		}
 
+		//Since 5.3
 		[Obsolete("Use constructor with tenantIdentifier")]
 		public CacheKey(object id, IType type, string entityOrRoleName, ISessionFactoryImplementor factory)
 		{

src/NHibernate/Connection/IConnectionAccess.cs

@@ -12,7 +12,7 @@ public partial interface IConnectionAccess
 		//ObtainConnection in hibernate
 		DbConnection GetConnection();
 
-		//Note: ReleaseConnection in hibernate
+		//ReleaseConnection in hibernate
 		void CloseConnection(DbConnection conn);
 
 		string ConnectionString { get; }

src/NHibernate/Impl/AbstractSessionImpl.cs

@@ -22,6 +22,7 @@
 using NHibernate.Persister.Entity;
 using NHibernate.Transaction;
 using NHibernate.Type;
+using NHibernate.Util;
 
 namespace NHibernate.Impl
 {
@@ -56,10 +57,12 @@ public ITransactionContext TransactionContext
 
 		internal AbstractSessionImpl() { }
 
-		private void ValidateTenantConfiguration(ISessionFactoryImplementor factory, TenantConfiguration tenantConfiguration)
+		private TenantConfiguration ValidateTenantConfiguration(ISessionFactoryImplementor factory, ISessionCreationOptions options)
 		{
 			if (factory.Settings.MultiTenancyStrategy == MultiTenancyStrategy.None)
-				return;
+				return null;
+
+			var tenantConfiguration = ReflectHelper.CastOrThrow<ISessionCreationOptionsWithMultiTenancy>(options, "multi-tenancy").TenantConfiguration;
 
 			if (string.IsNullOrEmpty(tenantConfiguration?.TenantIdentifier))
 			{
@@ -70,6 +73,8 @@ private void ValidateTenantConfiguration(ISessionFactoryImplementor factory, Ten
 			{
 				throw new ArgumentException($"Tenant configuration with ConnectionAccess defined is required for {factory.Settings.MultiTenancyStrategy} multi-tenancy strategy.");
 			}
+
+			return tenantConfiguration;
 		}
 
 		protected internal AbstractSessionImpl(ISessionFactoryImplementor factory, ISessionCreationOptions options)
@@ -82,8 +87,8 @@ protected internal AbstractSessionImpl(ISessionFactoryImplementor factory, ISess
 				_flushMode = options.InitialSessionFlushMode;
 				Interceptor = options.SessionInterceptor ?? EmptyInterceptor.Instance;
 
-				TenantConfiguration tenantConfiguration = options is ISessionCreationOptionsWithMultiTenancy multiTenancy ? multiTenancy.TenantConfiguration : null;
-				ValidateTenantConfiguration(factory, tenantConfiguration);
+				TenantConfiguration tenantConfiguration = ValidateTenantConfiguration(factory, options);
+
 				TenantIdentifier = tenantConfiguration?.TenantIdentifier;
 
 				if (options is ISharedSessionCreationOptions sharedOptions && sharedOptions.IsTransactionCoordinatorShared)