Use ConstructorExpression in CSharpRuntimeAnnotationCodeGenerator

src/EFCore/Design/Internal/CSharpRuntimeAnnotationCodeGenerator.cs

@@ -379,40 +379,15 @@ public static void Create(
         if (constructor == null
             || jsonReaderWriterProperty == null)
         {
-            AddNamespace(typeof(ValueConverter<,>), parameters.Namespaces);
-            AddNamespace(converter.ModelClrType, parameters.Namespaces);
-            AddNamespace(converter.ProviderClrType, parameters.Namespaces);
-
             var unsafeAccessors = new HashSet<string>();
 
             mainBuilder
-                .Append("new ValueConverter<")
-                .Append(codeHelper.Reference(converter.ModelClrType))
-                .Append(", ")
-                .Append(codeHelper.Reference(converter.ProviderClrType))
-                .AppendLine(">(")
-                .IncrementIndent()
-                .AppendLines(
-                    codeHelper.Expression(converter.ConvertToProviderExpression, parameters.Namespaces, unsafeAccessors),
-                    skipFinalNewline: true)
-                .AppendLine(",")
                 .AppendLines(
-                    codeHelper.Expression(converter.ConvertFromProviderExpression, parameters.Namespaces, unsafeAccessors),
+                    codeHelper.Expression(converter.ConstructorExpression, parameters.Namespaces, unsafeAccessors),
                     skipFinalNewline: true);
 
             Check.DebugAssert(
                 unsafeAccessors.Count == 0, "Generated unsafe accessors not handled: " + string.Join(Environment.NewLine, unsafeAccessors));
-
-            if (converter.ConvertsNulls)
-            {
-                mainBuilder
-                    .AppendLine(",")
-                    .Append("convertsNulls: true");
-            }
-
-            mainBuilder
-                .Append(")")
-                .DecrementIndent();
         }
         else
         {
@@ -549,7 +524,15 @@ public static void CreateJsonValueReaderWriter(
             return;
         }
 
-        CreateJsonValueReaderWriter(jsonValueReaderWriterType, parameters, codeHelper);
+        var unsafeAccessors = new HashSet<string>();
+
+        mainBuilder
+            .AppendLines(
+                codeHelper.Expression(jsonValueReaderWriter.ConstructorExpression, parameters.Namespaces, unsafeAccessors),
+                skipFinalNewline: true);
+
+        Check.DebugAssert(
+            unsafeAccessors.Count == 0, "Generated unsafe accessors not handled: " + string.Join(Environment.NewLine, unsafeAccessors));
     }
 
     /// <summary>

src/EFCore/Storage/ValueConversion/ValueConverter.cs

@@ -17,7 +17,7 @@ public abstract class ValueConverter
 {
     internal static readonly ConstructorInfo MappingHintsCtor
         = typeof(ConverterMappingHints).GetConstructor(
-            [typeof(int?), typeof(int?), typeof(int?), typeof(bool?), typeof(Func<IProperty, IEntityType, ValueGenerator>)])!;
+            [typeof(int?), typeof(int?), typeof(int?), typeof(bool?)])!;
 
     /// <summary>
     ///     Initializes a new instance of the <see cref="ValueConverter" /> class.

src/EFCore/Storage/ValueConversion/ValueConverter`.cs

@@ -189,20 +189,40 @@ public override Type ProviderClrType
         typeof(ConverterMappingHints)
     ])!;
 
+    private readonly ConstructorInfo _constructorInfoWithConvertsNulls = typeof(ValueConverter<TModel, TProvider>).GetConstructor(
+    [
+        typeof(Expression<Func<TModel, TProvider>>),
+        typeof(Expression<Func<TProvider, TModel>>),
+        typeof(bool),
+        typeof(ConverterMappingHints)
+    ])!;
+
     /// <inheritdoc />
     public override Expression ConstructorExpression
-        => Expression.New(
-            _constructorInfo,
-            ConvertToProviderExpression,
-            ConvertFromProviderExpression,
-            MappingHints != null
-                ? Expression.New(
+    {
+        get
+        {
+            var mappingHintsExpression = MappingHints != null
+                ? (Expression)Expression.New(
                     MappingHintsCtor,
                     Expression.Constant(MappingHints.Size, typeof(int?)),
                     Expression.Constant(MappingHints.Precision, typeof(int?)),
                     Expression.Constant(MappingHints.Scale, typeof(int?)),
-                    Expression.Constant(MappingHints.IsUnicode, typeof(bool?)),
-                    // valueGeneratorFactory is difficult to build using Expression trees and is obsolete
-                    Expression.Default(typeof(Func<IProperty, IEntityType, ValueGenerator>)))
-                : Expression.Default(typeof(ConverterMappingHints)));
+                    Expression.Constant(MappingHints.IsUnicode, typeof(bool?)))
+                : Expression.Default(typeof(ConverterMappingHints));
+
+            return ConvertsNulls
+                ? Expression.New(
+                    _constructorInfoWithConvertsNulls,
+                    ConvertToProviderExpression,
+                    ConvertFromProviderExpression,
+                    Expression.Constant(true),
+                    mappingHintsExpression)
+                : Expression.New(
+                    _constructorInfo,
+                    ConvertToProviderExpression,
+                    ConvertFromProviderExpression,
+                    mappingHintsExpression);
+        }
+    }
 }