Enhance nullability check for "==" and "!=" operators for LINQ provider

maca88 · maca88 · commit f2ea7b575dbd · 2019-10-04T10:00:08.000+02:00
diff --git a/src/NHibernate.DomainModel/Northwind/Entities/AnotherEntityRequired.cs b/src/NHibernate.DomainModel/Northwind/Entities/AnotherEntityRequired.cs
@@ -0,0 +1,33 @@
+﻿using System.Collections.Generic;
+
+namespace NHibernate.DomainModel.Northwind.Entities
+{
+	public class AnotherEntityRequired
+	{
+		public virtual int Id { get; set; }
+
+		public virtual string Output { get; set; }
+
+		public virtual string Input { get; set; }
+
+		public virtual Address Address { get; set; }
+
+		public virtual AnotherEntityNullability InputNullability { get; set; }
+
+		public virtual string NullableOutput { get; set; }
+
+		public virtual AnotherEntityRequired NullableAnotherEntityRequired { get; set; }
+
+		public virtual int? NullableAnotherEntityRequiredId { get; set; }
+
+		public virtual ISet<AnotherEntity> RelatedItems { get; set; } = new HashSet<AnotherEntity>();
+
+		public virtual bool? NullableBool { get; set; }
+	}
+
+	public enum AnotherEntityNullability
+	{
+		False = 0,
+		True = 1
+	}
+}
diff --git a/src/NHibernate.DomainModel/Northwind/Mappings/AnotherEntityRequired.hbm.xml b/src/NHibernate.DomainModel/Northwind/Mappings/AnotherEntityRequired.hbm.xml
@@ -0,0 +1,23 @@
+﻿<?xml version="1.0" encoding="utf-8" ?>
+<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2" namespace="NHibernate.DomainModel.Northwind.Entities" assembly="NHibernate.DomainModel">
+  <class name="AnotherEntityRequired" table="AnotherEntity" mutable="false" schema-action="none">
+    <id name="Id">
+      <generator class="native" />
+    </id>
+    <property name="Output" not-null="true" />
+    <property name="Input" not-null="true" />
+    <property name="NullableOutput" formula="Output" lazy="true" />
+    <property name="InputNullability" formula="case when Input is not null then 0 else 1 end" lazy="true" />
+    <property name="NullableAnotherEntityRequiredId" formula="Id" lazy="true" />
+    <property name="NullableBool" formula="null" lazy="true" />
+    <component name="Address" insert="false" update="false" lazy="true">
+      <property name="Street" formula="Input" access="field.camelcase-underscore" />
+      <property name="City" formula="Output" access="field.camelcase-underscore" />
+    </component>
+    <many-to-one name="NullableAnotherEntityRequired" formula="Id" />
+    <set name="RelatedItems" lazy="true" inverse="true">
+      <key column="Id"/>
+      <one-to-many class="AnotherEntity"/>
+    </set>
+  </class>
+</hibernate-mapping>
diff --git a/src/NHibernate.Test/Async/Linq/NullComparisonTests.cs b/src/NHibernate.Test/Async/Linq/NullComparisonTests.cs
diff --git a/src/NHibernate.Test/Linq/LinqTestCase.cs b/src/NHibernate.Test/Linq/LinqTestCase.cs
@@ -29,6 +29,7 @@ protected override string[] Mappings
 					"Northwind.Mappings.Supplier.hbm.xml",
 					"Northwind.Mappings.Territory.hbm.xml",
 					"Northwind.Mappings.AnotherEntity.hbm.xml",
+					"Northwind.Mappings.AnotherEntityRequired.hbm.xml",
 					"Northwind.Mappings.Role.hbm.xml",
 					"Northwind.Mappings.User.hbm.xml",
 					"Northwind.Mappings.TimeSheet.hbm.xml",
@@ -69,4 +70,4 @@ public static void AssertByIds<TEntity, TId>(IEnumerable<TEntity> entities, TId[
 			Assert.That(entities.Select(x => entityIdGetter(x)), Is.EquivalentTo(expectedIds));
 		}
 	}
-}
+}
diff --git a/src/NHibernate.Test/Linq/NullComparisonTests.cs b/src/NHibernate.Test/Linq/NullComparisonTests.cs
diff --git a/src/NHibernate/Linq/Expressions/NhAggregatedExpression.cs b/src/NHibernate/Linq/Expressions/NhAggregatedExpression.cs
@@ -16,6 +16,8 @@ protected NhAggregatedExpression(Expression expression, System.Type type)
 			Type = type;
 		}
 
+		public virtual bool AllowsNullableReturnType => true;
+
 		public sealed override System.Type Type { get; }
 
 		public Expression Expression { get; }
diff --git a/src/NHibernate/Linq/Expressions/NhCountExpression.cs b/src/NHibernate/Linq/Expressions/NhCountExpression.cs
@@ -10,6 +10,8 @@ protected NhCountExpression(Expression expression, System.Type type)
 		{
 		}
 
+		public override bool AllowsNullableReturnType => false;
+
 		protected override Expression Accept(NhExpressionVisitor visitor)
 		{
 			return visitor.VisitNhCount(this);
diff --git a/src/NHibernate/Linq/Functions/BaseHqlGeneratorForMethod.cs b/src/NHibernate/Linq/Functions/BaseHqlGeneratorForMethod.cs
@@ -7,10 +7,17 @@
 
 namespace NHibernate.Linq.Functions
 {
-    public abstract class BaseHqlGeneratorForMethod : IHqlGeneratorForMethod
-    {
-        public IEnumerable<MethodInfo> SupportedMethods { get; protected set; }
+	public abstract class BaseHqlGeneratorForMethod : IHqlGeneratorForMethod, IHqlGeneratorForMethodExtended
+	{
+		public IEnumerable<MethodInfo> SupportedMethods { get; protected set; }
 
-        public abstract HqlTreeNode BuildHql(MethodInfo method, Expression targetObject, ReadOnlyCollection<Expression> arguments, HqlTreeBuilder treeBuilder, IHqlExpressionVisitor visitor);
-    }
-}
+		public abstract HqlTreeNode BuildHql(MethodInfo method, Expression targetObject, ReadOnlyCollection<Expression> arguments, HqlTreeBuilder treeBuilder, IHqlExpressionVisitor visitor);
+
+		public virtual bool AllowsNullableReturnType(MethodInfo method) => true;
+
+		bool IHqlGeneratorForMethodExtended.AllowsNullableReturnType(MethodInfo method)
+		{
+			return AllowsNullableReturnType(method);
+		}
+	}
+}
diff --git a/src/NHibernate/Linq/Functions/CompareGenerator.cs b/src/NHibernate/Linq/Functions/CompareGenerator.cs
@@ -51,6 +51,7 @@ internal static bool IsCompareMethod(MethodInfo methodInfo)
 				   methodInfo.DeclaringType.FullName == "System.Data.Services.Providers.DataServiceProviderMethods";
 		}
 
+		public override bool AllowsNullableReturnType(MethodInfo method) => false;
 
 		public CompareGenerator()
 		{
@@ -102,4 +103,4 @@ public IHqlGeneratorForMethod GetMethodGenerator(MethodInfo method)
 
 		#endregion
 	}
-}
+}
diff --git a/src/NHibernate/Linq/Functions/DictionaryGenerator.cs b/src/NHibernate/Linq/Functions/DictionaryGenerator.cs
@@ -25,6 +25,8 @@ public override HqlTreeNode BuildHql(MethodInfo method, Expression targetObject,
 
 	public class DictionaryContainsKeyGenerator : BaseHqlGeneratorForMethod
 	{
+		public override bool AllowsNullableReturnType(MethodInfo method) => false;
+
 		public override HqlTreeNode BuildHql(MethodInfo method, Expression targetObject, ReadOnlyCollection<Expression> arguments, HqlTreeBuilder treeBuilder, IHqlExpressionVisitor visitor)
 		{
 			return treeBuilder.In(visitor.Visit(arguments[0]).AsExpression(), treeBuilder.Indices(visitor.Visit(targetObject).AsExpression()));
@@ -98,4 +100,4 @@ protected override string MethodName
 			get { return "get_Item"; }
 		}
 	}
-}
+}
diff --git a/src/NHibernate/Linq/Functions/EqualsGenerator.cs b/src/NHibernate/Linq/Functions/EqualsGenerator.cs
@@ -63,14 +63,14 @@ public EqualsGenerator()
 				};
 		}
 
+		public override bool AllowsNullableReturnType(MethodInfo method) => false;
+
 		public override HqlTreeNode BuildHql(MethodInfo method, Expression targetObject, ReadOnlyCollection<Expression> arguments, HqlTreeBuilder treeBuilder, IHqlExpressionVisitor visitor)
 		{
 			Expression lhs = arguments.Count == 1 ? targetObject : arguments[0];
 			Expression rhs = arguments.Count == 1 ? arguments[0] : arguments[1];
 
-			return treeBuilder.Equality(
-				visitor.Visit(lhs).ToArithmeticExpression(),
-				visitor.Visit(rhs).ToArithmeticExpression());
+			return visitor.Visit(Expression.Equal(lhs, rhs));
 		}
 	}
 }
diff --git a/src/NHibernate/Linq/Functions/GetValueOrDefaultGenerator.cs b/src/NHibernate/Linq/Functions/GetValueOrDefaultGenerator.cs
@@ -9,7 +9,7 @@
 
 namespace NHibernate.Linq.Functions
 {
-	internal class GetValueOrDefaultGenerator : IHqlGeneratorForMethod, IRuntimeMethodHqlGenerator
+	internal class GetValueOrDefaultGenerator : IHqlGeneratorForMethod, IRuntimeMethodHqlGenerator, IHqlGeneratorForMethodExtended
 	{
 		public bool SupportsMethod(MethodInfo method)
 		{
@@ -40,5 +40,7 @@ private static HqlExpression GetRhs(MethodInfo method, ReadOnlyCollection<Expres
 			var instance = returnType.IsValueType ? Activator.CreateInstance(returnType) : null;
 			return treeBuilder.Constant(instance);
 		}
+
+		public bool AllowsNullableReturnType(MethodInfo method) => !method.ReturnType.IsValueType;
 	}
 }
diff --git a/src/NHibernate/Linq/Functions/IHqlGeneratorForMethod.cs b/src/NHibernate/Linq/Functions/IHqlGeneratorForMethod.cs
@@ -12,4 +12,24 @@ public interface IHqlGeneratorForMethod
         IEnumerable<MethodInfo> SupportedMethods { get; }
         HqlTreeNode BuildHql(MethodInfo method, Expression targetObject, ReadOnlyCollection<Expression> arguments, HqlTreeBuilder treeBuilder, IHqlExpressionVisitor visitor);
     }
-}
+
+	// 6.0 TODO: Merge into IHqlGeneratorForMethod
+	internal interface IHqlGeneratorForMethodExtended
+	{
+		bool AllowsNullableReturnType(MethodInfo method);
+	}
+
+	internal static class HqlGeneratorForMethodExtensions
+	{
+		// 6.0 TODO: Remove
+		public static bool AllowsNullableReturnType(this IHqlGeneratorForMethod generator, MethodInfo method)
+		{
+			if (generator is IHqlGeneratorForMethodExtended extendedGenerator)
+			{
+				return extendedGenerator.AllowsNullableReturnType(method);
+			}
+
+			return true;
+		}
+	}
+}
diff --git a/src/NHibernate/Linq/Functions/QueryableGenerator.cs b/src/NHibernate/Linq/Functions/QueryableGenerator.cs
@@ -22,6 +22,8 @@ public AnyHqlGenerator()
 			};
 		}
 
+		public override bool AllowsNullableReturnType(MethodInfo method) => false;
+
 		public override HqlTreeNode BuildHql(MethodInfo method, Expression targetObject, ReadOnlyCollection<Expression> arguments, HqlTreeBuilder treeBuilder, IHqlExpressionVisitor visitor)
 		{
 			HqlAlias alias = null;
@@ -59,6 +61,8 @@ public AllHqlGenerator()
 			};
 		}
 
+		public override bool AllowsNullableReturnType(MethodInfo method) => false;
+
 		public override HqlTreeNode BuildHql(MethodInfo method, Expression targetObject, ReadOnlyCollection<Expression> arguments, HqlTreeBuilder treeBuilder, IHqlExpressionVisitor visitor)
 		{
 			// All has two arguments.  Arg 1 is the source and arg 2 is the predicate
@@ -148,6 +152,8 @@ public CollectionContainsGenerator()
 			                   	};
 		}
 
+		public override bool AllowsNullableReturnType(MethodInfo method) => false;
+
 		public override HqlTreeNode BuildHql(MethodInfo method, Expression targetObject, ReadOnlyCollection<Expression> arguments, HqlTreeBuilder treeBuilder, IHqlExpressionVisitor visitor)
 		{
 			// TODO - alias generator
@@ -170,4 +176,4 @@ public override HqlTreeNode BuildHql(MethodInfo method, Expression targetObject,
 					where));
 		}
 	}
-}
+}
diff --git a/src/NHibernate/Linq/Functions/StringGenerator.cs b/src/NHibernate/Linq/Functions/StringGenerator.cs
@@ -10,7 +10,7 @@
 
 namespace NHibernate.Linq.Functions
 {
-	public class LikeGenerator : IHqlGeneratorForMethod, IRuntimeMethodHqlGenerator
+	public class LikeGenerator : IHqlGeneratorForMethod, IRuntimeMethodHqlGenerator, IHqlGeneratorForMethodExtended
 	{
 		public IEnumerable<MethodInfo> SupportedMethods
 		{
@@ -58,6 +58,8 @@ public IHqlGeneratorForMethod GetMethodGenerator(MethodInfo method)
 		{
 			return this;
 		}
+
+		public bool AllowsNullableReturnType(MethodInfo method) => false;
 	}
 
 
@@ -81,6 +83,8 @@ public StartsWithGenerator()
 			SupportedMethods = new[] { ReflectHelper.GetMethodDefinition<string>(x => x.StartsWith(null)) };
 		}
 
+		public override bool AllowsNullableReturnType(MethodInfo method) => false;
+
 		public override HqlTreeNode BuildHql(MethodInfo method, Expression targetObject, ReadOnlyCollection<Expression> arguments, HqlTreeBuilder treeBuilder, IHqlExpressionVisitor visitor)
 		{
 			return treeBuilder.Like(
@@ -98,6 +102,8 @@ public EndsWithGenerator()
 			SupportedMethods = new[] { ReflectHelper.GetMethodDefinition<string>(x => x.EndsWith(null)) };
 		}
 
+		public override bool AllowsNullableReturnType(MethodInfo method) => false;
+
 		public override HqlTreeNode BuildHql(MethodInfo method, Expression targetObject, ReadOnlyCollection<Expression> arguments, HqlTreeBuilder treeBuilder, IHqlExpressionVisitor visitor)
 		{
 			return treeBuilder.Like(
@@ -115,6 +121,8 @@ public ContainsGenerator()
 			SupportedMethods = new[] { ReflectHelper.GetMethodDefinition<string>(x => x.Contains(null)) };
 		}
 
+		public override bool AllowsNullableReturnType(MethodInfo method) => false;
+
 		public override HqlTreeNode BuildHql(MethodInfo method, Expression targetObject, ReadOnlyCollection<Expression> arguments, HqlTreeBuilder treeBuilder, IHqlExpressionVisitor visitor)
 		{
 			return treeBuilder.Like(
diff --git a/src/NHibernate/Linq/Visitors/HqlGeneratorExpressionVisitor.cs b/src/NHibernate/Linq/Visitors/HqlGeneratorExpressionVisitor.cs

Original file line number	Diff line number	Diff line change
`@@ -29,6 +29,7 @@ protected override string[] Mappings`
`29`	`29`	`"Northwind.Mappings.Supplier.hbm.xml",`
`30`	`30`	`"Northwind.Mappings.Territory.hbm.xml",`
`31`	`31`	`"Northwind.Mappings.AnotherEntity.hbm.xml",`
	`32`	`+ "Northwind.Mappings.AnotherEntityRequired.hbm.xml",`
`32`	`33`	`"Northwind.Mappings.Role.hbm.xml",`
`33`	`34`	`"Northwind.Mappings.User.hbm.xml",`
`34`	`35`	`"Northwind.Mappings.TimeSheet.hbm.xml",`
`@@ -69,4 +70,4 @@ public static void AssertByIds<TEntity, TId>(IEnumerable<TEntity> entities, TId[`
`69`	`70`	`Assert.That(entities.Select(x => entityIdGetter(x)), Is.EquivalentTo(expectedIds));`
`70`	`71`	`}`
`71`	`72`	`}`
`72`		`-}`
	`73`	`+}`
Original file line number	Diff line number	Diff line change
`@@ -16,6 +16,8 @@ protected NhAggregatedExpression(Expression expression, System.Type type)`
`16`	`16`	`Type = type;`
`17`	`17`	`}`
`18`	`18`
	`19`	`+ public virtual bool AllowsNullableReturnType => true;`
	`20`	`+`
`19`	`21`	`public sealed override System.Type Type { get; }`
`20`	`22`
`21`	`23`	`public Expression Expression { get; }`
Original file line number	Diff line number	Diff line change
`@@ -10,6 +10,8 @@ protected NhCountExpression(Expression expression, System.Type type)`
`10`	`10`	`{`
`11`	`11`	`}`
`12`	`12`
	`13`	`+ public override bool AllowsNullableReturnType => false;`
	`14`	`+`
`13`	`15`	`protected override Expression Accept(NhExpressionVisitor visitor)`
`14`	`16`	`{`
`15`	`17`	`return visitor.VisitNhCount(this);`
Original file line number	Diff line number	Diff line change
`@@ -51,6 +51,7 @@ internal static bool IsCompareMethod(MethodInfo methodInfo)`
`51`	`51`	`methodInfo.DeclaringType.FullName == "System.Data.Services.Providers.DataServiceProviderMethods";`
`52`	`52`	`}`
`53`	`53`
	`54`	`+ public override bool AllowsNullableReturnType(MethodInfo method) => false;`
`54`	`55`
`55`	`56`	`public CompareGenerator()`
`56`	`57`	`{`
`@@ -102,4 +103,4 @@ public IHqlGeneratorForMethod GetMethodGenerator(MethodInfo method)`
`102`	`103`
`103`	`104`	`#endregion`
`104`	`105`	`}`
`105`		`-}`
	`106`	`+}`
Original file line number	Diff line number	Diff line change
`@@ -25,6 +25,8 @@ public override HqlTreeNode BuildHql(MethodInfo method, Expression targetObject,`
`25`	`25`
`26`	`26`	`public class DictionaryContainsKeyGenerator : BaseHqlGeneratorForMethod`
`27`	`27`	`{`
	`28`	`+ public override bool AllowsNullableReturnType(MethodInfo method) => false;`
	`29`	`+`
`28`	`30`	`public override HqlTreeNode BuildHql(MethodInfo method, Expression targetObject, ReadOnlyCollection<Expression> arguments, HqlTreeBuilder treeBuilder, IHqlExpressionVisitor visitor)`
`29`	`31`	`{`
`30`	`32`	`return treeBuilder.In(visitor.Visit(arguments[0]).AsExpression(), treeBuilder.Indices(visitor.Visit(targetObject).AsExpression()));`
`@@ -98,4 +100,4 @@ protected override string MethodName`
`98`	`100`	`get { return "get_Item"; }`
`99`	`101`	`}`
`100`	`102`	`}`
`101`		`-}`
	`103`	`+}`