NH-3919 - Letting the type choose being overridden or not.

Author: fredericDelaporte

src/NHibernate/Async/Type/AbstractType.cs

@@ -248,4 +248,4 @@ public abstract Task<object> ReplaceAsync(object original, object current, ISess
 
 		public abstract Task<bool> IsDirtyAsync(object old, object current, bool[] checkable, ISessionImplementor session, CancellationToken cancellationToken);
 	}
-}
+}

src/NHibernate/Async/Type/ComponentType.cs

@@ -357,4 +357,4 @@ public override async Task<bool> IsModifiedAsync(object old, object current, boo
 			return false;
 		}
 	}
-}
+}

src/NHibernate/Async/Type/CompositeCustomType.cs

@@ -181,4 +181,4 @@ public override Task<object> ReplaceAsync(object original, object current, ISess
 		}
 
 	}
-}
+}

src/NHibernate/Async/Type/OneToOneType.cs

@@ -164,4 +164,4 @@ public override Task<object> AssembleAsync(object cached, ISessionImplementor se
 			}
 		}
 	}
-}
+}

src/NHibernate/Dialect/Dialect.cs

@@ -293,12 +293,11 @@ protected void RegisterColumnType(DbType code, string name)
 		}
 
 		/// <summary>
-		/// Refine the <see cref="SqlType"/>s for an <see cref="IType"/>.
+		/// Refine provided <see cref="SqlType"/>s.
 		/// </summary>
-		/// <param name="type">The <see cref="IType"/>.</param>
-		/// <param name="types">The original <see cref="SqlType"/>s for the <paramref name="type"/>.</param>
+		/// <param name="types">The original <see cref="SqlType"/>s.</param>
 		/// <returns>Refined <see cref="SqlType"/>s.</returns>
-		public virtual SqlType[] RefineSqlTypes(IType type, SqlType[] types) =>
+		public virtual SqlType[] RefineSqlTypes(SqlType[] types) =>
 			types;
 
 		#endregion

src/NHibernate/Dialect/MsSql2008Dialect.cs

@@ -1,6 +1,7 @@
 using System;
 using System.Collections.Generic;
 using System.Data;
+using System.Linq;
 using NHibernate.Dialect.Function;
 using NHibernate.Driver;
 using NHibernate.SqlTypes;
@@ -87,21 +88,18 @@ protected override void RegisterDefaultProperties()
 				: 1;
 
 		/// <inheritdoc />
-		public override SqlType[] RefineSqlTypes(IType type, SqlType[] types)
+		public override SqlType[] RefineSqlTypes(SqlType[] types)
 		{
+			types = base.RefineSqlTypes(types);
+	
 #pragma warning disable 618
-			if (!KeepDateTime)
+			if (KeepDateTime)
+				return types;
 #pragma warning restore 618
-			{
-				switch (type)
-				{
-					// Switch built-in DateTime types and their descendants to DateTime2.
-					case DateTimeType _:
-					case TimestampType _:
-						return new[] { SqlTypeFactory.DateTime2 };
-				}
-			}
-			return base.RefineSqlTypes(type, types);
+
+			return types
+				.Select(t => SqlTypeFactory.DateTime.Equals(t) ? SqlTypeFactory.DateTime2 : t)
+				.ToArray();
 		}
 	}
 }

src/NHibernate/NHibernate.csproj

@@ -1,38 +1,30 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <Import Project="../../build-common/NHibernate.props" />
-
   <PropertyGroup>
     <Description>An object persistence library for relational databases.</Description>
-
     <TargetFramework>net461</TargetFramework>
     <NoWarn>$(NoWarn);3001;3002;3003;3005;1591</NoWarn>
     <SignAssembly>True</SignAssembly>
     <AssemblyOriginatorKeyFile>..\NHibernate.snk</AssemblyOriginatorKeyFile>
     <GenerateDocumentationFile>true</GenerateDocumentationFile>
   </PropertyGroup>
-
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|AnyCPU'">
     <TreatWarningsAsErrors>True</TreatWarningsAsErrors>
     <TreatSpecificWarningsAsErrors />
   </PropertyGroup>
-
   <ItemGroup>
     <None Remove="**\*.g" />
     <None Remove="**\*.xsd" />
   </ItemGroup>
-
   <ItemGroup>
     <Antlr3 Include="**\*.g" />
   </ItemGroup>
-
   <ItemGroup>
     <EmbeddedResource Include="**\*.xsd" />
   </ItemGroup>
-
   <ItemGroup>
     <None Include="..\NHibernate.snk" Link="NHibernate.snk" />
   </ItemGroup>
-
   <ItemGroup>
     <PackageReference Include="Antlr3.CodeGenerator" Version="3.5.2-beta1">
       <PrivateAssets>All</PrivateAssets>
@@ -42,11 +34,9 @@
     <PackageReference Include="Remotion.Linq" Version="2.1.2" />
     <PackageReference Include="Remotion.Linq.EagerFetching" Version="2.1.0" />
   </ItemGroup>
-
   <ItemGroup>
     <Reference Include="System.ServiceModel" />
     <Reference Include="System.Transactions" />
     <Reference Include="System.Configuration" />
   </ItemGroup>
-
-</Project>
+</Project>

src/NHibernate/Type/AbstractType.cs

@@ -182,6 +182,23 @@ public override int GetHashCode()
 		/// <inheritdoc />
 		public abstract SqlType[] SqlTypes(IMapping mapping);
 
+		/// <summary>
+		/// Refine the sql types.
+		/// </summary>
+		/// <param name="types">The types to refine.</param>
+		/// <param name="mapping">The mapping for which to refine <paramref name="types"/>.</param>
+		/// <returns>The refined types.</returns>
+		protected SqlType[] RefineSqlTypes(SqlType[] types, IMapping mapping) =>
+			AllowSqlTypeOverride
+				? mapping?.Dialect.RefineSqlTypes(types) ?? types
+				: types;
+
+		/// <summary>
+		/// Does this type allow its default <see cref="SqlType" /> to be overridden?
+		/// <see langword="false" /> by default for <see cref="AbstractType" />.
+		/// </summary>
+		protected virtual bool AllowSqlTypeOverride => false;
+
 		/// <inheritdoc />
 		public abstract int GetColumnSpan(IMapping mapping);
 
@@ -275,4 +292,4 @@ public abstract object Replace(object original, object current, ISessionImplemen
 
 		public abstract bool IsDirty(object old, object current, bool[] checkable, ISessionImplementor session);
 	}
-}
+}

src/NHibernate/Type/AnyType.cs

@@ -153,10 +153,8 @@ public override System.Type ReturnedClass
 			get { return typeof(object); }
 		}
 
-		public override SqlType[] SqlTypes(IMapping mapping)
-		{
-			return ArrayHelper.Join(metaType.SqlTypes(mapping), identifierType.SqlTypes(mapping));
-		}
+		public override SqlType[] SqlTypes(IMapping mapping) =>
+			RefineSqlTypes(ArrayHelper.Join(metaType.SqlTypes(mapping), identifierType.SqlTypes(mapping)), mapping);
 
 		public override string ToLoggableString(object value, ISessionFactoryImplementor factory)
 		{

src/NHibernate/Type/ClassMetaType.cs

@@ -14,11 +14,10 @@ namespace NHibernate.Type
 	[Serializable]
 	public partial class ClassMetaType : AbstractType
 	{
-		public override SqlType[] SqlTypes(IMapping mapping)
-		{
-			var types = new[] { NHibernateUtil.String.SqlType };
-			return mapping?.Dialect.RefineSqlTypes(this, types) ?? types;
-		}
+		public override SqlType[] SqlTypes(IMapping mapping) =>
+			RefineSqlTypes(new[] { NHibernateUtil.String.SqlType }, mapping);
+
+		protected override bool AllowSqlTypeOverride => true;
 
 		public override int GetColumnSpan(IMapping mapping)
 		{