STJ Source Generator bloats the assembly when used with records

[aromaa]

Description

Records contains a property EqualityContract of type Type. This leads to the generator generating serializers for many of the reflection related types as for example Type, ConstructorInfo, MethodInfo, Assembly, Module, etc.

Also it would be nice if there was a way to prevent generating metadata for non-public members.

Repo

internal static class Program
{
	private static void Main()
	{
		JsonSerializer.Serialize(new Test(), typeof(Test), JsonContext.Default);
	}
}

internal sealed record Test;

[JsonSerializable(typeof(Test))]
internal sealed partial class JsonContext : JsonSerializerContext
{
}

Tagging subscribers to this area: @eiriktsarpalis, @layomia
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Issue Details

---

Description

Records contains a property EqualityContract of type Type. This leads to the generator generating serializers for many of the reflection related types as for example Type, ConstructorInfo, MethodInfo, Assembly, Module, etc.

Also it would be nice if there was a way to prevent generating metadata for non-public members.

Repo

internal static class Program
{
	private static void Main()
	{
		JsonSerializer.Serialize(new Test(), typeof(Test), JsonContext.Default);
	}
}

internal sealed record Test;

[JsonSerializable(typeof(Test))]
internal sealed partial class JsonContext : JsonSerializerContext
{
}

Author:	aromaa
Assignees:	-
Labels:	area-System.Text.Json, untriaged
Milestone:	-

[eiriktsarpalis]

Hi @aromaa, what version of the sdk are you using to reproduce this. Using your reproduction on 6.0.100-rc.1.21415.3 I'm getting the following generated code:

// <auto-generated/>
#nullable enable

namespace Repro
{

    public static partial class Program
    {

        internal sealed partial class JsonContext
        {
            private global::System.Text.Json.Serialization.Metadata.JsonTypeInfo<global::Repro.Program.MyRecord>? _MyRecord;
            public global::System.Text.Json.Serialization.Metadata.JsonTypeInfo<global::Repro.Program.MyRecord> MyRecord
            {
                get
                {
                    if (_MyRecord == null)
                    {
                        global::System.Text.Json.Serialization.JsonConverter? customConverter;
                            if (Options.Converters.Count > 0 && (customConverter = GetRuntimeProvidedCustomConverter(typeof(global::Repro.Program.MyRecord))) != null)
                            {
                                _MyRecord = global::System.Text.Json.Serialization.Metadata.JsonMetadataServices.CreateValueInfo<global::Repro.Program.MyRecord>(Options, customConverter);
                            }
                            else
                            {
                                global::System.Text.Json.Serialization.Metadata.JsonObjectInfoValues<global::Repro.Program.MyRecord> objectInfo = new global::System.Text.Json.Serialization.Metadata.JsonObjectInfoValues<global::Repro.Program.MyRecord>()
                                {
                                    ObjectCreator = static () => new global::Repro.Program.MyRecord(),
                                    ObjectWithParameterizedConstructorCreator = null,
                                    PropertyMetadataInitializer = MyRecordPropInit,
                                    ConstructorParameterMetadataInitializer = null,
                                    NumberHandling = default,
                                    SerializeHandler = MyRecordSerialize
                                };
                
                                _MyRecord = global::System.Text.Json.Serialization.Metadata.JsonMetadataServices.CreateObjectInfo<global::Repro.Program.MyRecord>(Options, objectInfo);
                            }
                    }
            
                    return _MyRecord;
                }
            }
            
            private static global::System.Text.Json.Serialization.Metadata.JsonPropertyInfo[] MyRecordPropInit(global::System.Text.Json.Serialization.JsonSerializerContext context)
            {
                global::Repro.Program.JsonContext jsonContext = (global::Repro.Program.JsonContext)context;
                global::System.Text.Json.JsonSerializerOptions options = context.Options;
            
                global::System.Text.Json.Serialization.Metadata.JsonPropertyInfo[] properties = global::System.Array.Empty<global::System.Text.Json.Serialization.Metadata.JsonPropertyInfo>();
            
                return properties;
            }
            
            private static void MyRecordSerialize(global::System.Text.Json.Utf8JsonWriter writer, global::Repro.Program.MyRecord value)
            {
                if (value == null)
                {
                    writer.WriteNullValue();
                    return;
                }
            
                writer.WriteStartObject();
            
                writer.WriteEndObject();
            }
        }
}
}

which on quick inspection doesn't seem to include any properties.

[aromaa]

This seems to be fixed on RC builds. I was using 6.0.0-preview.7.21377.19. Doesn't repro with 6.0.0-rc.2.21425.6.