NSwag add x-enum-varnames tag to all enums

Question

Is it possible to add x-enum-varnames to all enums in NSwag? I have this example but then you have to specify all the enums. Is there a more generic solution? Also, this example creates a second instance ResultCode2 which I don't understand.

https://github.com/RicoSuter/NSwag/issues/1993

public class NSwagProcessor : IOperationProcessor
{
    public bool Process( OperationProcessorContext context )
    {
        JsonSchema schema = JsonSchema.FromType<ResultCode>();
        if( schema.ExtensionData == null )
        {
            schema.ExtensionData = new Dictionary<string, object>();
        }

        string[] enumerationNames = new string[ schema.EnumerationNames.Count ];
        schema.EnumerationNames.CopyTo( enumerationNames, 0 );
        schema.ExtensionData.Add( "x-enum-varnames", enumerationNames );

        if( context.Settings.TypeMappers.Any( t => t.MappedType == typeof( ResultCode ) ) == false )
        {
            context.Settings.TypeMappers.Add( new ObjectTypeMapper( typeof( ResultCode ), schema ) );
        }

        return true;
    }
}

...

services.AddOpenApiDocument( config => {
    config.OperationProcessors.Add( new NSwagProcessor() );
} );

This creates:

"ResultCode": {
    "type": "integer",
    "description": "",
    "x-enumNames": [
      "Error",
      "Success"
    ],
    "enum": [
      0,
      1
    ]
  },

...

"ResultCode2": {
    "title": "ResultCode",
    "type": "integer",
    "description": "",
    "x-enumNames": [
      "Error",
      "Success"
    ],
    "enum": [
      0,
      1
    ],
    "x-enum-varnames": [
      "Error",
      "Success"
    ]
  },

Answer 1

I found another solution, you can add a Schema processor to the NSwag openapi generation. By adding the following schema processor:

public class XEnumVarnamesNswagSchemaProcessor : ISchemaProcessor
{
    public void Process(SchemaProcessorContext context)
    {
        if (context.Type.IsEnum)
        {
            if (context.Schema.ExtensionData is not null)
            {
                context.Schema.ExtensionData.Add("x-enum-varnames", context.Schema.EnumerationNames.ToArray());
            }
            else
            {
                context.Schema.ExtensionData = new Dictionary<string, object>()
                {
                    {"x-enum-varnames", context.Schema.EnumerationNames.ToArray()}
                };
            }
        }
    }
}

An extra field will be added to all openapi enum schemas/types. You need to add the processor to the NSwag service in Startup.cs.

services.AddOpenApiDocument(configuration =>
        {
            configuration.SchemaProcessors.Add(new XEnumVarnamesNswagSchemaProcessor());
        });