Update IIsEntityDecider to use ExpressionsHelper.TryGetMappedType

Author: maca88

src/NHibernate/Linq/ReWriters/AddJoinsReWriter.cs

@@ -1,18 +1,19 @@
 using System;
 using System.Collections.Specialized;
 using System.Linq;
+using System.Linq.Expressions;
 using NHibernate.Engine;
 using NHibernate.Linq.Clauses;
 using NHibernate.Linq.Visitors;
+using NHibernate.Util;
 using Remotion.Linq;
 using Remotion.Linq.Clauses;
 
 namespace NHibernate.Linq.ReWriters
 {
 	internal interface IIsEntityDecider
 	{
-		bool IsEntity(System.Type type);
-		bool IsIdentifier(System.Type type, string propertyName);
+		bool IsEntity(MemberExpression expression, out bool isIdentifier);
 	}
 
 	public class AddJoinsReWriter : NhQueryModelVisitorBase, IIsEntityDecider
@@ -26,8 +27,8 @@ private AddJoinsReWriter(ISessionFactoryImplementor sessionFactory, QueryModel q
 		{
 			_sessionFactory = sessionFactory;
 			var joiner = new Joiner(queryModel, AddJoin);
-			_memberExpressionJoinDetector = new MemberExpressionJoinDetector(this, joiner);
-			_whereJoinDetector = new WhereJoinDetector(this, joiner);
+			_memberExpressionJoinDetector = new MemberExpressionJoinDetector(this, joiner, _sessionFactory);
+			_whereJoinDetector = new WhereJoinDetector(this, joiner, _sessionFactory);
 		}
 
 		public static void ReWrite(QueryModel queryModel, VisitorParameters parameters)
@@ -77,11 +78,15 @@ public override void VisitJoinClause(JoinClause joinClause, QueryModel queryMode
 			_currentJoin = null;
 		}
 
+		// Since v5.3
+		[Obsolete("This method has no usages and will be removed in a future version")]
 		public bool IsEntity(System.Type type)
 		{
 			return _sessionFactory.GetImplementors(type.FullName).Any();
 		}
 
+		// Since v5.3
+		[Obsolete("This method has no usages and will be removed in a future version")]
 		public bool IsIdentifier(System.Type type, string propertyName)
 		{
 			var metadata = _sessionFactory.GetClassMetadata(type);
@@ -99,5 +104,14 @@ private void AddJoin(QueryModel queryModel, NhJoinClause joinClause)
 
 			queryModel.BodyClauses.Add(joinClause);
 		}
+
+		bool IIsEntityDecider.IsEntity(MemberExpression expression, out bool isIdentifier)
+		{
+			isIdentifier =
+				ExpressionsHelper.TryGetMappedType(_sessionFactory, expression, out var mappedType, out var entityPersister, out _, out var memberPath)
+				&& entityPersister?.IdentifierPropertyName == memberPath;
+
+			return mappedType?.IsEntityType == true;
+		}
 	}
 }

src/NHibernate/Linq/Visitors/MemberExpressionJoinDetector.cs

@@ -1,6 +1,7 @@
 using System.Collections;
 using System.Collections.Generic;
 using System.Linq.Expressions;
+using NHibernate.Engine;
 using NHibernate.Linq.Expressions;
 using NHibernate.Linq.ReWriters;
 using Remotion.Linq.Clauses;
@@ -18,16 +19,21 @@ internal class MemberExpressionJoinDetector : RelinqExpressionVisitor
 	{
 		private readonly IIsEntityDecider _isEntityDecider;
 		private readonly IJoiner _joiner;
+		private readonly ISessionFactoryImplementor _sessionFactory;
 
 		private bool _requiresJoinForNonIdentifier;
 		private bool _preventJoinsInConditionalTest;
 		private bool _hasIdentifier;
 		private int _memberExpressionDepth;
 
-		public MemberExpressionJoinDetector(IIsEntityDecider isEntityDecider, IJoiner joiner)
+		public MemberExpressionJoinDetector(
+			IIsEntityDecider isEntityDecider,
+			IJoiner joiner,
+			ISessionFactoryImplementor sessionFactory)
 		{
 			_isEntityDecider = isEntityDecider;
 			_joiner = joiner;
+			_sessionFactory = sessionFactory;
 		}
 
 		protected override Expression VisitMember(MemberExpression expression)
@@ -39,7 +45,7 @@ protected override Expression VisitMember(MemberExpression expression)
 				return base.VisitMember(expression);
 			}
 
-			var isIdentifier = _isEntityDecider.IsIdentifier(expression.Expression.Type, expression.Member.Name);
+			var isEntity = _isEntityDecider.IsEntity(expression, out var isIdentifier);
 			if (isIdentifier)
 				_hasIdentifier = true;
 			if (!isIdentifier)
@@ -50,7 +56,7 @@ protected override Expression VisitMember(MemberExpression expression)
 			if (!isIdentifier)
 				_memberExpressionDepth--;
 
-			if (_isEntityDecider.IsEntity(expression.Type) &&
+			if (isEntity &&
 				((_requiresJoinForNonIdentifier && !_hasIdentifier) || _memberExpressionDepth > 0) &&
 				_joiner.CanAddJoin(expression))
 			{

src/NHibernate/Linq/Visitors/WhereJoinDetector.cs

@@ -2,6 +2,7 @@
 using System.Collections.Generic;
 using System.Linq;
 using System.Linq.Expressions;
+using NHibernate.Engine;
 using NHibernate.Linq.ReWriters;
 using Remotion.Linq.Clauses;
 using Remotion.Linq.Clauses.Expressions;
@@ -61,6 +62,7 @@ internal class WhereJoinDetector : RelinqExpressionVisitor
 		// TODO: There are a number of types of expressions that we didn't handle here due to time constraints.  For example, the ?: operator could be checked easily.
 		private readonly IIsEntityDecider _isEntityDecider;
 		private readonly IJoiner _joiner;
+		private readonly ISessionFactoryImplementor _sessionFactory;
 
 		private readonly Stack<bool> _handled = new Stack<bool>();
 
@@ -70,10 +72,14 @@ internal class WhereJoinDetector : RelinqExpressionVisitor
 		// The following is used for member expressions traversal.
 		private int _memberExpressionDepth;
 
-		internal WhereJoinDetector(IIsEntityDecider isEntityDecider, IJoiner joiner)
+		internal WhereJoinDetector(
+			IIsEntityDecider isEntityDecider,
+			IJoiner joiner,
+			ISessionFactoryImplementor sessionFactory)
 		{
 			_isEntityDecider = isEntityDecider;
 			_joiner = joiner;
+			_sessionFactory = sessionFactory;
 		}
 
 		public Expression Transform(Expression expression)
@@ -314,10 +320,7 @@ protected override Expression VisitMember(MemberExpression expression)
 				return base.VisitMember(expression);
 			}
 
-			var isIdentifier = _isEntityDecider.IsIdentifier(
-				expression.Expression.Type,
-				expression.Member.Name);
-
+			var isEntity = _isEntityDecider.IsEntity(expression, out var isIdentifier);
 			if (!isIdentifier)
 				_memberExpressionDepth++;
 
@@ -327,7 +330,7 @@ protected override Expression VisitMember(MemberExpression expression)
 				_memberExpressionDepth--;
 
 			ExpressionValues values = _values.Pop().Operation(pvs => pvs.MemberAccess(expression.Type));
-			if (_isEntityDecider.IsEntity(expression.Type))
+			if (isEntity)
 			{
 				// Don't add joins for things like a.B == a.C where B and C are entities.
 				// We only need to join B when there's something like a.B.D.