[Bug]: Nullable return types. Cannot implement null result

[liven-maksim-infotecs]

Describe the bug 🐞

Methods with nullable response types have not null default value. It's an implementation of dto class with default fields.

Step to reproduce

1. Create an api with method that returns NotFound if id == 0 (e.x.)

[HttpGet()]
async Task<ActionResult<SomeDto>> Get(int id, CancellationToken token)
{
     if (id == 0) {
         return NotFound();
     }
     
     return await dataFactory.CreateAsync(id, token);
}

1. Create api client interface for this method

public interface ISomeClient {
     [Get("api/some")]
     Task<SomeDto?> GetById(int id);
}

2. Chagne refit settings with custom exception factory to handle 404 Not Found

public Task<Exception?> CreateAsync(HttpResponseMessage responseMessage) =>
        responseMessage.StatusCode == HttpStatusCode.NotFound
            ? Task.FromResult<Exception?>(null)
            : factory.CreateAsync(responseMessage);

3. Invoke web request with refit-generated client with id = 0;
4. Result is not null but a dto instance with default field values.

Reproduction repository

https://github.com/reactiveui/refit

Expected behavior

Generated client's method reposonse type must be nullable, default value for this method must be null instead of dto instance with default fields.

Screenshots 🖼️

IDE

Inteliji Rider

Operating system

Windows

Version

21H2 19044.3570

Device

PC

Refit Version

7.0.0

Additional information ℹ️

No response