Fix lazy property handling with field accessors (#3345)

Fixes #3333

Co-authored-by: sashakboo <31510839+sashakboo@users.noreply.github.com>

Author: bahusoid

src/NHibernate.Test/Async/LazyProperty/LazyPropertyFixture.cs

@@ -13,10 +13,10 @@
 using System.Linq;
 using NHibernate.Cfg;
 using NHibernate.Intercept;
+using NHibernate.Linq;
 using NHibernate.Tuple.Entity;
 using NUnit.Framework;
 using NUnit.Framework.Constraints;
-using NHibernate.Linq;
 
 namespace NHibernate.Test.LazyProperty
 {
@@ -69,6 +69,7 @@ protected override void OnSetUp()
 					Id = 1,
 					ALotOfText = "a lot of text ...",
 					Image = new byte[10],
+					NoSetterImage = new byte[10],
 					FieldInterceptor = "Why not that name?"
 				});
 				tx.Commit();
@@ -393,5 +394,58 @@ public async Task CanMergeTransientWithLazyPropertyInCollectionAsync()
 				Assert.That(book.Words.First().Content, Is.EqualTo(new byte[1] { 0 }));
 			}
 		}
+
+		[Test(Description = "GH-3333")]
+		public async Task GetLazyPropertyWithNoSetterAccessor_PropertyShouldBeInitializedAsync()
+		{
+			using (ISession s = OpenSession())
+			{
+				var book = await (s.GetAsync<Book>(1));
+				var image = book.NoSetterImage;
+				// Fails. Property remains uninitialized after it has been accessed.
+				Assert.That(NHibernateUtil.IsPropertyInitialized(book, "NoSetterImage"), Is.True);
+			}
+		}
+
+		[Test(Description = "GH-3333")]
+		public async Task GetLazyPropertyWithNoSetterAccessorTwice_ResultsAreSameObjectAsync()
+		{
+			using (ISession s = OpenSession())
+			{
+				var book = await (s.GetAsync<Book>(1));
+				var image = book.NoSetterImage;
+				var sameImage = book.NoSetterImage;
+				// Fails. Each call to a property getter returns a new object.
+				Assert.That(ReferenceEquals(image, sameImage), Is.True);
+			}
+		}
+
+		[Test]
+		public async Task CanSetValueForLazyPropertyNoSetterAsync()
+		{
+			Book book;
+			using (ISession s = OpenSession())
+			{
+				book = await (s.GetAsync<Book>(1));
+				book.NoSetterImage = new byte[]{10};
+			}
+
+			Assert.That(NHibernateUtil.IsPropertyInitialized(book, nameof(book.NoSetterImage)), Is.True);
+			CollectionAssert.AreEqual(book.NoSetterImage, new byte[] { 10 });
+		}
+
+		[Test]
+		public async Task CanFetchLazyPropertyNoSetterAsync()
+		{
+			using (ISession s = OpenSession())
+			{
+				var book = await (s
+					.Query<Book>()
+					.Fetch(x => x.NoSetterImage)
+					.FirstAsync(x => x.Id == 1));
+
+				Assert.That(NHibernateUtil.IsPropertyInitialized(book, nameof(book.NoSetterImage)), Is.True);
+			}
+		}
 	}
 }

src/NHibernate.Test/LazyProperty/Book.cs

@@ -17,6 +17,14 @@ public virtual string ALotOfText
 
 		public virtual byte[] Image { get; set; }
 
+		private byte[] _NoSetterImage;
+
+		public virtual byte[] NoSetterImage
+		{
+			get { return _NoSetterImage; }
+			set { _NoSetterImage = value; }
+		}
+
 		public virtual string FieldInterceptor { get; set; }
 
 		public virtual IList<Word> Words { get; set; }

src/NHibernate.Test/LazyProperty/LazyPropertyFixture.cs

@@ -3,6 +3,7 @@
 using System.Linq;
 using NHibernate.Cfg;
 using NHibernate.Intercept;
+using NHibernate.Linq;
 using NHibernate.Tuple.Entity;
 using NUnit.Framework;
 using NUnit.Framework.Constraints;
@@ -57,6 +58,7 @@ protected override void OnSetUp()
 					Id = 1,
 					ALotOfText = "a lot of text ...",
 					Image = new byte[10],
+					NoSetterImage = new byte[10],
 					FieldInterceptor = "Why not that name?"
 				});
 				tx.Commit();
@@ -387,5 +389,58 @@ public void CanMergeTransientWithLazyPropertyInCollection()
 				Assert.That(book.Words.First().Content, Is.EqualTo(new byte[1] { 0 }));
 			}
 		}
+
+		[Test(Description = "GH-3333")]
+		public void GetLazyPropertyWithNoSetterAccessor_PropertyShouldBeInitialized()
+		{
+			using (ISession s = OpenSession())
+			{
+				var book = s.Get<Book>(1);
+				var image = book.NoSetterImage;
+				// Fails. Property remains uninitialized after it has been accessed.
+				Assert.That(NHibernateUtil.IsPropertyInitialized(book, "NoSetterImage"), Is.True);
+			}
+		}
+
+		[Test(Description = "GH-3333")]
+		public void GetLazyPropertyWithNoSetterAccessorTwice_ResultsAreSameObject()
+		{
+			using (ISession s = OpenSession())
+			{
+				var book = s.Get<Book>(1);
+				var image = book.NoSetterImage;
+				var sameImage = book.NoSetterImage;
+				// Fails. Each call to a property getter returns a new object.
+				Assert.That(ReferenceEquals(image, sameImage), Is.True);
+			}
+		}
+
+		[Test]
+		public void CanSetValueForLazyPropertyNoSetter()
+		{
+			Book book;
+			using (ISession s = OpenSession())
+			{
+				book = s.Get<Book>(1);
+				book.NoSetterImage = new byte[]{10};
+			}
+
+			Assert.That(NHibernateUtil.IsPropertyInitialized(book, nameof(book.NoSetterImage)), Is.True);
+			CollectionAssert.AreEqual(book.NoSetterImage, new byte[] { 10 });
+		}
+
+		[Test]
+		public void CanFetchLazyPropertyNoSetter()
+		{
+			using (ISession s = OpenSession())
+			{
+				var book = s
+					.Query<Book>()
+					.Fetch(x => x.NoSetterImage)
+					.First(x => x.Id == 1);
+
+				Assert.That(NHibernateUtil.IsPropertyInitialized(book, nameof(book.NoSetterImage)), Is.True);
+			}
+		}
 	}
 }

src/NHibernate.Test/LazyProperty/Mappings.hbm.xml

@@ -11,6 +11,7 @@
 		<property name="Name" />
 		<property name="ALotOfText" lazy="true" />
 		<property name="Image" lazy="true" />
+		<property name="NoSetterImage" access="nosetter.pascalcase-underscore" lazy="true" />
 		<property name="FieldInterceptor" />
     <bag name="Words" inverse="true" generic="true" cascade="all-delete-orphan" lazy="true" >
       <key column="ParentId" />

src/NHibernate/Tuple/Entity/PocoEntityTuplizer.cs

@@ -12,6 +12,7 @@
 using NHibernate.Util;
 using System.Runtime.Serialization;
 using NHibernate.Bytecode.Lightweight;
+using NHibernate.Intercept;
 
 namespace NHibernate.Tuple.Entity
 {
@@ -306,6 +307,16 @@ public override bool IsLifecycleImplementor
 
 		public override void SetPropertyValue(object entity, int i, object value)
 		{
+			// If there is no property setter we need to manually intercept value for proper lazy property handling.
+			if (IsInstrumented && setters[i].PropertyName == null)
+			{
+				IFieldInterceptor interceptor = _enhancementMetadata.ExtractInterceptor(entity);
+				if (interceptor != null)
+				{
+					value = interceptor.Intercept(entity, EntityMetamodel.PropertyNames[i], value, true);
+				}
+			}
+
 			if (isBytecodeProviderImpl && optimizer?.AccessOptimizer != null)
 			{
 				optimizer.AccessOptimizer.SetPropertyValue(entity, i, value);