[Bug]: A nullable struct property results in an invalid generated schema.

[igor-korolyov]

Describe the bug

Invalid schema has been generated in cases where a type has a nullable property of a custom struct.

Version 6.2.2 behaves in the expected way.

Expected behavior

A valid schema should be generated.

Actual behavior

An invalid (and recursive) schema has been generated.

Steps to reproduce

public class Program
{
    public static void Main(string[] args)
    {
        var builder = WebApplication.CreateBuilder(args);

        // Add services to the container.

        builder.Services.AddControllers();
        // Learn more about configuring Swagger/OpenAPI at https://aka.ms/aspnetcore/swashbuckle
        builder.Services.AddEndpointsApiExplorer();
        builder.Services.AddSwaggerGen();

        var app = builder.Build();

        // Configure the HTTP request pipeline.
        if (app.Environment.IsDevelopment())
        {
            app.UseSwagger();
            app.UseSwaggerUI();
        }

        app.UseAuthorization();


        app.MapControllers();

        app.Run();
    }
}

[ApiController]
[Route("[controller]/[action]")]
public class TestController : ControllerBase
{
    [HttpGet]
    public TestResponse Get()
    {
        return new()
        {
            Foo = new(1, 2),
        };
    }
}

public record TestResponse
{
    public TestStruct? Foo { get; init; }
}

public record struct TestStruct(int A, int B);

Exception(s) (if any)

No response

Swashbuckle.AspNetCore version

6.7.0

.NET Version

net8.0

Anything else?

No response

[shihabmridha]

We are having the same issue.
+1

[martincostello]

Looks like this was broken by #2941.

[jgarciadelanoceda]

Sorry for the inconvenience!

[ahoke-cr]

This is doubly bad because object types as references that are properties of an object or request are not allowed to have descriptions. This makes 6.7.0 unusable for us as it results in most of our API docs being unusable with unhelpful descriptions of object properties/request parameters being the description of the schema itself (empty in the case of these "NullableInt32" etc. types).

[martincostello]

Version 6.7.1 is now available from NuGet.org which resolves this issue.