Use ConstructorExpression in CSharpRuntimeAnnotationCodeGenerator

[Copilot]

The compiled-model generator hand-rolled C# for ValueConverter and JsonValueReaderWriter instances via reflection-based string building, duplicating logic already available on each type's constructor expression metadata. This change has the generator render those expressions through ICSharpHelper.Expression(...), with reviewer follow-up fixes applied.

Changes

• CSharpRuntimeAnnotationCodeGenerator

  • Plain converters now emit codeHelper.Expression(converter.ConstructorExpressionWithoutMappingHints, ...) so compiled models don't redundantly persist ConverterMappingHints when type mapping is already explicit.
  • Leaf JSON reader/writers emit codeHelper.Expression(jsonValueReaderWriter.ConstructorExpression, ...).
  • Recursion is intentionally retained for CollectionToJsonStringConverter, IJsonConvertedValueReaderWriter, and ICompositeJsonValueReaderWriter: their ConstructorExpression embeds Expression.Constant(converterInstance), which cannot be rendered to source.
  • missingUnsafeAccessors is created only in the scope where constructor expressions are rendered and asserted empty there (post-validation only).

• ValueConverter / ValueConverter<TModel,TProvider>

  • Added ConstructorExpressionWithoutMappingHints (base virtual + generic override).
  • ConstructorExpression still handles convertsNulls via the 4-arg constructor when needed.
  • ConstructorExpressionWithoutMappingHints uses dedicated 2-arg (convertTo, convertFrom) and 3-arg (convertTo, convertFrom, convertsNulls) constructors so no ConverterMappingHints argument is passed at all — not even default(ConverterMappingHints).

• ValueConverter.MappingHintsCtor (latent bug)

  • Previously resolved a non-existent 5-arg ConverterMappingHints constructor and returned null. Corrected to the current 4-arg (int?, int?, int?, bool?) constructor.

• Regenerated baselines

  • Compiled-model baselines were regenerated (including Cosmos and SqlServer) to match the new output.
  • src/EFCore/EFCore.baseline.json was updated by running EFCore.ApiBaseline.Tests locally.

[Copilot]

Pull request overview

This PR updates EF Core’s compiled-model code generation to reuse each ValueConverter/JsonValueReaderWriter instance’s ConstructorExpression instead of hand-rolled C# string construction. This consolidates logic, fixes a latent reflection bug in MappingHintsCtor, and makes generated compiled-model baselines more faithful by including mapping-hint values.

Changes:

• Switch CSharpRuntimeAnnotationCodeGenerator to render converter/reader-writer construction via ICSharpHelper.Expression(...ConstructorExpression...) (while keeping the existing recursive special-cases where ConstructorExpression contains non-renderable constants).
• Fix ValueConverter<TModel,TProvider>.ConstructorExpression to correctly represent ConvertsNulls by using the 4-arg constructor when needed, and to emit mapping-hints via the correct ConverterMappingHints(int?, int?, int?, bool?) constructor.
• Regenerate InMemory/Sqlite compiled-model scaffolding baselines to reflect the new (single-line) emitted constructor expressions and mapping-hint arguments.

Reviewed changes

Copilot reviewed 18 out of 20 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
src/EFCore/Design/Internal/CSharpRuntimeAnnotationCodeGenerator.cs	Use ConstructorExpression rendering for plain converters and leaf JSON reader/writers; retain recursion for converted/composite cases.
src/EFCore/Storage/ValueConversion/ValueConverter.cs	Fix MappingHintsCtor reflection to target the existing 4-arg ConverterMappingHints constructor.
src/EFCore/Storage/ValueConversion/ValueConverter`.cs	Update ConstructorExpression to include ConvertsNulls and emit mapping-hints via the corrected ctor.
test/EFCore.Sqlite.FunctionalTests/Scaffolding/Baselines/No_NativeAOT/ManyTypesEntityType.cs	Baseline regen: converters now include mapping-hints args and single-line ctor emission.
test/EFCore.Sqlite.FunctionalTests/Scaffolding/Baselines/BigModel/PrincipalBaseEntityType.cs	Baseline regen for converter/JSON reader-writer construction output.
test/EFCore.Sqlite.FunctionalTests/Scaffolding/Baselines/BigModel/OwnedTypeEntityType.cs	Baseline regen for converter/JSON reader-writer construction output.
test/EFCore.Sqlite.FunctionalTests/Scaffolding/Baselines/BigModel/OwnedType0EntityType.cs	Baseline regen for converter/JSON reader-writer construction output.
test/EFCore.Sqlite.FunctionalTests/Scaffolding/Baselines/BigModel/DependentBaseEntityType.cs	Baseline regen for converter/JSON reader-writer construction output.
test/EFCore.Sqlite.FunctionalTests/Scaffolding/Baselines/BigModel_with_JSON_columns/PrincipalBaseEntityType.cs	Baseline regen for converter/JSON reader-writer construction output.
test/EFCore.Sqlite.FunctionalTests/Scaffolding/Baselines/BigModel_with_JSON_columns/OwnedTypeEntityType.cs	Baseline regen for converter/JSON reader-writer construction output.
test/EFCore.Sqlite.FunctionalTests/Scaffolding/Baselines/BigModel_with_JSON_columns/OwnedType0EntityType.cs	Baseline regen for converter/JSON reader-writer construction output.
test/EFCore.Sqlite.FunctionalTests/Scaffolding/Baselines/BigModel_with_JSON_columns/DependentBaseEntityType.cs	Baseline regen for converter/JSON reader-writer construction output.
test/EFCore.InMemory.FunctionalTests/Scaffolding/Baselines/Self_referential_property/SelfReferentialEntityEntityType.cs	Baseline regen: converter ctor now includes mapping-hints emission.
test/EFCore.InMemory.FunctionalTests/Scaffolding/Baselines/RelationshipCycles/PrincipalBaseEntityType.cs	Baseline regen for converter/JSON reader-writer construction output.
test/EFCore.InMemory.FunctionalTests/Scaffolding/Baselines/No_NativeAOT/ManyTypesEntityType.cs	Baseline regen: converters now include mapping-hints args and single-line ctor emission.
test/EFCore.InMemory.FunctionalTests/Scaffolding/Baselines/Custom_value_converter/MyEntityEntityType.cs	Baseline regen for converter construction output.
test/EFCore.InMemory.FunctionalTests/Scaffolding/Baselines/ComplexTypes/PrincipalDerivedEntityType.cs	Baseline regen for converter/JSON reader-writer construction output (complex types).
test/EFCore.InMemory.FunctionalTests/Scaffolding/Baselines/ComplexTypes/PrincipalBaseEntityType.cs	Baseline regen for converter/JSON reader-writer construction output (complex types).

[Copilot]

Pull request overview

Copilot reviewed 18 out of 20 changed files in this pull request and generated 1 comment.

[Copilot]

Pull request overview

Copilot reviewed 24 out of 26 changed files in this pull request and generated 4 comments.

[github-actions]

API review baseline changes for src/EFCore/EFCore.baseline.json

Show diff

The diff below was generated by ApiChief between the base and the PR.

  class Microsoft.EntityFrameworkCore.Storage.ValueConversion.ValueConverter<TModel,
      TProvider> : Microsoft.EntityFrameworkCore.Storage.ValueConversion.ValueConverter
- ValueConverter(Expression<Func<TModel, TProvider>> convertToProviderExpression, Expression<Func<TProvider, TModel>> convertFromProviderExpression,
-     ConverterMappingHints? mappingHints = null);
+ ValueConverter(Expression<Func<TModel, TProvider>> convertToProviderExpression, Expression<Func<TProvider, TModel>> convertFromProviderExpression);
+ ValueConverter(Expression<Func<TModel, TProvider>> convertToProviderExpression, Expression<Func<TProvider, TModel>> convertFromProviderExpression,
+     ConverterMappingHints? mappingHints);
+ override Expression ConstructorExpressionWithoutMappingHints { get; }