[NSwagStudio] Nullable Timespan in ASP web api 2 generates different C# method signature when using Output type of "OpenApi3" vs "Swagger2"

Hey, I’m using NSwagStudio x64 v11.19.2.0 With below ASP web api 2 controller:

    [RoutePrefix("api/values")]
    public class ValuesController : ApiController
    {
        [HttpPut, Route("{id}/expiry")]
        [SwaggerResponse(200, typeof(bool))]
        public async Task<IHttpActionResult> PutExpiry([FromUri] string id, [FromBody] TimeSpan? expiry)
        {
            await Task.Yield();

            var success = true;
            return Ok(success);
        }
    }

    public class ValueDto
    {
        [Required]
        public string Id { get; set; }
    }

In NSwag Studio I get different C# client when selecting Swagger2 vs OpenApi3.

Swagger2:

public System.Threading.Tasks.Task<bool> PutExpiryAsync(string id, System.TimeSpan? expiry)

OpenApi3:

public System.Threading.Tasks.Task<bool> PutExpiryAsync(string id, System.TimeSpan expiry)

Notice in OpenApi3 the System.TimeSpan is not nullable. For now I manually change the generated code to ‘TimeSpan?’, but fear another dev might overwrite it in future when they re-generate client.

[RicoSuter]

I’ve added AllowNullableBodyParameters setting (default: true) - now nullable should be correctly handled in OpenAPI 3 (without changing anything). In the next major release (v12) the default will be set to false to reflect the current implementation of ASP.NET Core 2+… Keeping default true to not break anyone now.

[G4rce]

Just verified 😃 works on x64 11.20.0.0.