Query: Cleanup in optional dependent SQL feature

src/EFCore.Relational/Query/RelationalEntityShaperExpression.cs

@@ -35,9 +35,9 @@ public RelationalEntityShaperExpression(
             [NotNull] IEntityType entityType,
             [NotNull] Expression valueBufferExpression,
             bool nullable,
-            [NotNull] LambdaExpression discriminatorCondition)
+            [CanBeNull] LambdaExpression materializationCondition)
             : base(entityType, valueBufferExpression, nullable,
-                  discriminatorCondition ?? GenerateMaterializationCondition(Check.NotNull(entityType, nameof(entityType)), nullable))
+                  materializationCondition ?? GenerateMaterializationCondition(Check.NotNull(entityType, nameof(entityType)), nullable))
         {
         }
 
@@ -157,7 +157,7 @@ public override EntityShaperExpression Update(Expression valueBufferExpression)
             Check.NotNull(valueBufferExpression, nameof(valueBufferExpression));
 
             return valueBufferExpression != ValueBufferExpression
-                ? new RelationalEntityShaperExpression(EntityType, valueBufferExpression, IsNullable, DiscriminatorCondition)
+                ? new RelationalEntityShaperExpression(EntityType, valueBufferExpression, IsNullable, MaterializationCondition)
                 : this;
         }
     }

src/EFCore/Properties/CoreStrings.resx

@@ -1363,4 +1363,7 @@
   <data name="FunctionOnClient" xml:space="preserve">
     <value>The '{methodName}' method is not supported because the query has switched to client-evaluation. Inspect the log to determine which query expressions are triggering client-evaluation.</value>
   </data>
+  <data name="QueryEntityMaterializationConditionWrongShape" xml:space="preserve">
+    <value>Materialization condition passed for entity shaper of entity type '{entityType}' is not of correct shape. Materialization condition must be LambdaExpression of 'Func&lt;ValueBuffer, IEntityType&gt;'</value>
+  </data>
 </root>

src/EFCore/Query/EntityShaperExpression.cs

@@ -38,30 +38,29 @@ protected EntityShaperExpression(
             [NotNull] IEntityType entityType,
             [NotNull] Expression valueBufferExpression,
             bool nullable,
-            [CanBeNull] LambdaExpression discriminatorCondition)
+            [CanBeNull] LambdaExpression materializationCondition)
         {
             Check.NotNull(entityType, nameof(entityType));
             Check.NotNull(valueBufferExpression, nameof(valueBufferExpression));
 
-            if (discriminatorCondition == null)
+            if (materializationCondition == null)
             {
-                discriminatorCondition = GenerateDiscriminatorCondition(entityType, nullable);
+                materializationCondition = GenerateMaterializationCondition(entityType, nullable);
             }
-            else if (discriminatorCondition.Parameters.Count != 1
-                    || discriminatorCondition.Parameters[0].Type != typeof(ValueBuffer)
-                    || discriminatorCondition.ReturnType != typeof(IEntityType))
+            else if (materializationCondition.Parameters.Count != 1
+                    || materializationCondition.Parameters[0].Type != typeof(ValueBuffer)
+                    || materializationCondition.ReturnType != typeof(IEntityType))
             {
-                throw new InvalidOperationException(
-                    "Discriminator condition must be lambda expression of type Func<ValueBuffer, IEntityType>.");
+                throw new InvalidOperationException(CoreStrings.QueryEntityMaterializationConditionWrongShape(entityType.DisplayName()));
             }
 
             EntityType = entityType;
             ValueBufferExpression = valueBufferExpression;
             IsNullable = nullable;
-            DiscriminatorCondition = discriminatorCondition;
+            MaterializationCondition = materializationCondition;
         }
 
-        private LambdaExpression GenerateDiscriminatorCondition(IEntityType entityType, bool nullable)
+        private LambdaExpression GenerateMaterializationCondition(IEntityType entityType, bool nullable)
         {
             var valueBufferParameter = Parameter(typeof(ValueBuffer));
             Expression body;
@@ -117,7 +116,7 @@ private LambdaExpression GenerateDiscriminatorCondition(IEntityType entityType,
         public virtual IEntityType EntityType { get; }
         public virtual Expression ValueBufferExpression { get; }
         public virtual bool IsNullable { get; }
-        public virtual LambdaExpression DiscriminatorCondition { get; }
+        public virtual LambdaExpression MaterializationCondition { get; }
 
         protected override Expression VisitChildren(ExpressionVisitor visitor)
         {
@@ -139,7 +138,7 @@ public virtual EntityShaperExpression WithEntityType([NotNull] IEntityType entit
 
         public virtual EntityShaperExpression MarkAsNullable()
             => !IsNullable
-                // Marking nullable requires recomputation of Discriminator condition
+                // Marking nullable requires recomputation of materialization condition
                 ? new EntityShaperExpression(EntityType, ValueBufferExpression, true)
                 : this;
 
@@ -148,7 +147,7 @@ public virtual EntityShaperExpression Update([NotNull] Expression valueBufferExp
             Check.NotNull(valueBufferExpression, nameof(valueBufferExpression));
 
             return valueBufferExpression != ValueBufferExpression
-                ? new EntityShaperExpression(EntityType, valueBufferExpression, IsNullable, DiscriminatorCondition)
+                ? new EntityShaperExpression(EntityType, valueBufferExpression, IsNullable, MaterializationCondition)
                 : this;
         }
 

src/EFCore/Query/ShapedQueryCompilingExpressionVisitor.cs

@@ -452,9 +452,9 @@ private Expression MaterializeEntity(
                 expressions.Add(
                     Expression.Assign(concreteEntityTypeVariable,
                         ReplacingExpressionVisitor.Replace(
-                            entityShaperExpression.DiscriminatorCondition.Parameters[0],
+                            entityShaperExpression.MaterializationCondition.Parameters[0],
                             valueBufferExpression,
-                            entityShaperExpression.DiscriminatorCondition.Body)));
+                            entityShaperExpression.MaterializationCondition.Body)));
 
                 var concreteEntityTypes = entityType.GetConcreteDerivedTypesInclusive().ToArray();
                 var discriminatorProperty = entityType.GetDiscriminatorProperty();
@@ -550,14 +550,6 @@ private BlockExpression CreateFullMaterializeExpression(
 
                 return Expression.Block(blockExpressions);
             }
-
-            private static readonly MethodInfo _createUnableToDiscriminateException
-                = typeof(EntityMaterializerInjectingExpressionVisitor).GetTypeInfo()
-                    .GetDeclaredMethod(nameof(CreateUnableToDiscriminateException));
-
-            [UsedImplicitly]
-            private static Exception CreateUnableToDiscriminateException(IEntityType entityType, object discriminator)
-                => new InvalidOperationException(CoreStrings.UnableToDiscriminate(entityType.DisplayName(), discriminator?.ToString()));
         }
     }
 }