Support mixed formulas and columns (#1808)

Many mapping elements allow to define their columns or formulas by
nested elements, but most of them do not support having both nested
columns and formulas.

Follow-up to NH-2117, which has added this support to  one-to-many.

Throw on invalid usages of columns and formulas attributes and elements

Author: fredericDelaporte

doc/reference/modules/example_mappings.xml

@@ -496,7 +496,6 @@ alter table line_items
 
         </sect2>
 
-<!-- This example is not supported by NHibernate, because HbmManyToMany lacks a ColumnsAndFormulas handling
         <sect2 id="example-mappings-miscellaneous-m2mcomposite">
             <title>Many-to-many with shared composite key attribute</title>
 
@@ -535,8 +534,12 @@ alter table line_items
     </set>
 </class>]]></programlisting>
 
+            <para>
+                This case requires mixing column and formula under the <literal>&lt;many-to-many&gt;</literal>
+                element, which is supported only since NHibernate 5.2.
+            </para>
+
         </sect2>
--->
 
         <sect2 id="example-mappings-miscellaneous-contentdiscriminator">
             <title>Content based discrimination</title>

src/NHibernate.Test/Async/NHSpecificTest/GH1759/ColumnsAndFormulasFixture.cs

@@ -0,0 +1,221 @@
+//------------------------------------------------------------------------------
+// <auto-generated>
+//     This code was generated by AsyncGenerator.
+//
+//     Changes to this file may cause incorrect behavior and will be lost if
+//     the code is regenerated.
+// </auto-generated>
+//------------------------------------------------------------------------------
+
+
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using NHibernate.Dialect;
+using NUnit.Framework;
+using NHibernate.Linq;
+
+namespace NHibernate.Test.NHSpecificTest.GH1759
+{
+	using System.Threading.Tasks;
+	[TestFixture]
+	public class ColumnsAndFormulasFixtureAsync : BugTestCase
+	{
+		// In fact most of the test happens at mapping compilation.
+		protected override bool AppliesTo(Dialect.Dialect dialect)
+		{
+			// Uses some formulas with SLQ-Server transact SQL functions
+			return dialect is MsSql2000Dialect;
+		}
+
+		protected override void OnSetUp()
+		{
+			using (var session = OpenSession())
+			using (var transaction = session.BeginTransaction())
+			{
+				var bob =
+					new User
+					{
+						Name = "Bob",
+						Org = "Eg",
+						DepartureDate = DateTime.Parse("2012-07-01"),
+						Hiring = new DateSpan
+						{
+							Date1 = DateTime.Parse("2001-01-01")
+						}
+					};
+				session.Save(bob);
+
+				var sally =
+					new User
+					{
+						Name = "Sally",
+						Org = "Eg",
+						Hiring = new DateSpan
+						{
+							Date1 = DateTime.Parse("2006-01-08")
+						}
+					};
+				session.Save(sally);
+
+				var g1 = new Group { Name = "Salesperson", Org = "Eg" };
+				g1.DateSpans.Add(new DateSpan { Date1 = DateTime.Parse("2000-12-31") });
+				session.Save(g1);
+
+				var g2 = new Group { Name = "Manager", Org = "Eg" };
+				session.Save(g2);
+
+				bob.Groups.Add(g1);
+				g1.CommentsByUser.Add(bob, "He is gone, maybe he can be cleaned-up from the group.");
+				sally.Groups.Add(g1);
+				sally.Groups.Add(g2);
+
+				session.Flush();
+
+				// Needs to be done after the Flush, because this creates a circular reference.
+				bob.MainGroupName = "Salesperson";
+				sally.MainGroupName = "Salesperson";
+
+				transaction.Commit();
+			}
+		}
+
+		protected override void OnTearDown()
+		{
+			using (var session = OpenSession())
+			using (var transaction = session.BeginTransaction())
+			{
+				// HQL "delete from" does neither handle the many-to-many table, nor the element table.
+				// So using ISession.Delete instead of ISession.CreateQuery("delete...
+				session.Delete("from User");
+				session.Delete("from Group");
+
+				transaction.Commit();
+			}
+		}
+
+		[Test]
+		public async Task CheckManyToManyAsync()
+		{
+			using (var session = OpenSession())
+			using (var tx = session.BeginTransaction())
+			{
+				var bob = await (session.Query<User>().SingleAsync(u => u.Name == "Bob" && u.Org == "Eg"));
+				var sally = await (session.Query<User>().SingleAsync(u => u.Name == "Sally" && u.Org == "Eg"));
+				var salesperson = await (session.Query<Group>().SingleAsync(u => u.Name == "Salesperson" && u.Org == "Eg"));
+				var manager = await (session.Query<Group>().SingleAsync(u => u.Name == "Manager" && u.Org == "Eg"));
+
+				Assert.That(
+					bob.Groups,
+					Has.Count.EqualTo(1)
+					   .And.One.EqualTo(salesperson));
+				Assert.That(
+					sally.Groups,
+					Has.Count.EqualTo(2)
+					   .And.One.EqualTo(salesperson)
+					   .And.One.EqualTo(manager));
+				Assert.That(
+					salesperson.Users,
+					Has.Count.EqualTo(2)
+					   .And.One.EqualTo(bob)
+					   .And.One.EqualTo(sally));
+				Assert.That(
+					manager.Users,
+					Has.Count.EqualTo(1)
+					   .And.One.EqualTo(sally));
+
+				await (tx.CommitAsync());
+			}
+		}
+
+		[Test]
+		public async Task CheckPropertyAsync()
+		{
+			using (var session = OpenSession())
+			using (var tx = session.BeginTransaction())
+			{
+				var bob = await (session.Query<User>().SingleAsync(u => u.Name == "Bob" && u.Org == "Eg"));
+				var sally = await (session.Query<User>().SingleAsync(u => u.Name == "Sally" && u.Org == "Eg"));
+
+				Assert.That(
+					bob.Hiring,
+					Has.Property(nameof(DateSpan.Date1)).EqualTo(DateTime.Parse("2001-01-01"))
+					   .And.Property(nameof(DateSpan.Date2)).EqualTo(bob.DepartureDate));
+				Assert.That(
+					sally.Hiring,
+					Has.Property(nameof(DateSpan.Date1)).EqualTo(DateTime.Parse("2006-01-08"))
+					   .And.Property(nameof(DateSpan.Date2)).EqualTo(sally.DepartureDate));
+
+				sally.DepartureDate = DateTime.Today;
+
+				await (tx.CommitAsync());
+			}
+
+			using (var session = OpenSession())
+			using (var tx = session.BeginTransaction())
+			{
+				var sally = await (session.Query<User>().SingleAsync(u => u.Name == "Sally" && u.Org == "Eg"));
+				Assert.That(sally.DepartureDate, Is.Not.Null);
+				Assert.That(
+					sally.Hiring,
+					Has.Property(nameof(DateSpan.Date1)).EqualTo(DateTime.Parse("2006-01-08"))
+					   .And.Property(nameof(DateSpan.Date2)).EqualTo(sally.DepartureDate));
+
+				await (tx.CommitAsync());
+			}
+		}
+
+		[Test]
+		public async Task CheckElementAsync()
+		{
+			using (var session = OpenSession())
+			using (var tx = session.BeginTransaction())
+			{
+				var salesperson = await (session.Query<Group>().SingleAsync(u => u.Name == "Salesperson" && u.Org == "Eg"));
+
+				Assert.That(
+					salesperson.DateSpans,
+					Has.Count.GreaterThan(0)
+					   .And.All.Property(nameof(DateSpan.Date2)).EqualTo(DateTime.Parse("2000-12-31").AddYears(2)));
+
+				await (tx.CommitAsync());
+			}
+		}
+
+		[Test, Ignore("Needs an unrelated additional simple fix in OneToManyPersister")]
+		public async Task CheckMapKeyAsync()
+		{
+			using (var session = OpenSession())
+			using (var tx = session.BeginTransaction())
+			{
+				var salesperson = await (session.Query<Group>().SingleAsync(u => u.Name == "Salesperson" && u.Org == "Eg"));
+
+				Assert.That(
+					salesperson.UsersByHiring,
+					Has.Count.EqualTo(2)
+					   .And.One.Property(nameof(KeyValuePair<DateSpan, User>.Key)).Property(nameof(DateSpan.Date2)).Null
+					   .And.One.Property(nameof(KeyValuePair<DateSpan, User>.Key)).Property(nameof(DateSpan.Date2)).EqualTo(DateTime.Parse("2012-07-01")));
+
+				await (tx.CommitAsync());
+			}
+		}
+
+		[Test]
+		public async Task CheckMapKeyManyToManyAsync()
+		{
+			using (var session = OpenSession())
+			using (var tx = session.BeginTransaction())
+			{
+				var bob = await (session.Query<User>().SingleAsync(u => u.Name == "Bob" && u.Org == "Eg"));
+				var salesperson = await (session.Query<Group>().SingleAsync(u => u.Name == "Salesperson" && u.Org == "Eg"));
+
+				Assert.That(
+					salesperson.CommentsByUser,
+					Has.Count.EqualTo(1)
+					   .And.One.Property(nameof(KeyValuePair<User, User>.Key)).EqualTo(bob).And.Property(nameof(KeyValuePair<User, User>.Value)).Length.GreaterThan(0));
+
+				await (tx.CommitAsync());
+			}
+		}
+	}
+}