Schema Do not take in account Nullable Record inside record

[aygalinc]

Hello ,

I am on .Net 7 with nullable enable and on the following reporducer i do not get my property PnlGenerated mark as nullable inside the generated OpenApi specification.

The swassbuckle configuration :

        options.SchemaFilter<RequireAllPropertiesPropertiesSchemaFilter>();
   options.SupportNonNullableReferenceTypes();
        options.MapType<DateOnly>(() => new OpenApiSchema { Type = "string", Format = "date" });
    }
}

public sealed class RequireAllPropertiesPropertiesSchemaFilter : ISchemaFilter
{
    /// <summary>
    /// Add to model.Required all properties where Nullable is false.
    /// </summary>
    public void Apply(OpenApiSchema schema, SchemaFilterContext context)
    {
        var additionalRequiredProps = schema.Properties
            .Where(x => !schema.Required.Contains(x.Key))
            .Select(x => x.Key);

        foreach (var propKey in additionalRequiredProps)
        {
            schema.Required.Add(propKey);
        }
    }
}

the Controller and its DTO :

  [HttpPost(
        "xxx")]
    [ProducesResponseType(typeof(ComputedPeriodDto), StatusCodes.Status200OK)]
    [SwaggerOperation(OperationId = "ComputePeriodForConvertToForecast")]
    public async Task<ActionResult<ComputedPeriod>> ComputePeriodForConvertToForecast(
        [FromRoute, Required] int companyId, [FromRoute, Required] Guid pnlId, [FromBody] ConvertToForecastDto dto)
    {
        var conversionPeriod = xxx;
        return this.Ok(conversionPeriod.MapToDto());
    }
}

public sealed record ConvertToForecastDto(int? ScenarioId, bool GenerateForecastInPast = false);

public sealed record ComputedPeriodDto(
    PeriodDto? PnlGenerated, [property: JsonRequired] PeriodDto PnlFile);

public sealed record PeriodDto([property: JsonRequired] DateOnly StartDate, [property: JsonRequired] DateOnly EndDate);

Generate for ComputedPEriodDto :

 "ComputedPeriodDto": {
        "required": [
          "pnlFile",
          "pnlGenerated"
        ],
        "type": "object",
        "properties": {
          "pnlFile": {
            "$ref": "#/components/schemas/PeriodDto"
          },
          "pnlGenerated": {
            "$ref": "#/components/schemas/PeriodDto"
          }
        },
        "additionalProperties": false
      },

I would have expect to see :

 "ComputedPeriodDto": {
        "required": [
          "pnlFile",
          "pnlGenerated"
        ],
        "type": "object",
        "properties": {
          "pnlFile": {
            "$ref": "#/components/schemas/PeriodDto"
          },
          "pnlGenerated": {
            "$ref": "#/components/schemas/PeriodDto",
nullable: true
          }
        },
        "additionalProperties": false
      },

[p-m-j]

@aygalinc I had the same issue, but this can be solved by calling UseAllOfToExtendReferenceSchemas on SwaggerGenOptions

services.AddSwaggerGen(opt =>
{
    opt.SupportNonNullableReferenceTypes();
    opt.UseAllOfToExtendReferenceSchemas();
});

[aygalinc]

Hey seems to do the trick but weird that it not works out of the box.

[Havunen]

This might be fixed in DotSwashbuckle, can you test using it please.
https://github.com/Havunen/DotSwashbuckle
https://www.nuget.org/packages/DotSwashbuckle.AspNetCore

[martincostello]

To make issue tracking a bit less overwhelming for the new maintainers (see #2778), I've created a new tracking issue to roll-up various nullability issues here: #2793.

We'll refer back to this issue from there and include it as part of resolving that issue, but I'm going to close this one to help prune the backlog.