Serialization of XML with FastEndpoints

Program.cs

var bld = WebApplication.CreateBuilder();
bld.Services
   .AddSingleton(typeof(IRequestBinder<>), typeof(CustomBinder<>))
   .AddFastEndpoints()
   .SwaggerDocument();

var app = bld.Build();
app.UseAuthorization()
   .UseFastEndpoints()
   .UseSwaggerGen();
app.Run();

public class CustomBinder<TRequest> : RequestBinder<TRequest> where TRequest : notnull
{
    public override async ValueTask<TRequest> BindAsync(BinderContext ctx, CancellationToken cancellation)
    {
        if (ctx.HttpContext.Request.ContentType == "application/xml")
        {
            var serializer = new XmlSerializer(typeof(TRequest));
            using var reader = new StreamReader(ctx.HttpContext.Request.Body);
            string requestBody = await reader.ReadToEndAsync();
            using var stringReader = new StringReader(requestBody);
            return (TRequest)serializer.Deserialize(stringReader);
        }
        return await base.BindAsync(ctx, cancellation);
    }
}

public static class EndpointExtensions
{
    public static async Task SendXMLAsync<TResponse>(this IEndpoint ep,
                                                     TResponse response,
                                                     int statusCode = 200,
                                                     string contentType = "application/xml",
                                                     CancellationToken cancellationToken = default)
    {
        ep.HttpContext.MarkResponseStart();
        ep.HttpContext.Response.StatusCode = statusCode;
        ep.HttpContext.Response.ContentType = contentType;
        var xmlSerializer = new XmlSerializer(typeof(TResponse));
        using var stream = new MemoryStream();
        xmlSerializer.Serialize(stream, response);
        stream.Position = 0;
        await stream.CopyToAsync(ep.HttpContext.Response.Body, cancellationToken);
    }
}

public class Request
{
    public string FirstName { get; set; }
    public string LastName { get; set; }
}

public class Response
{
    public string FullName { get; set; }
}

public class Endpoint : Endpoint<Request, Response>
{
    public override void Configure()
    {
        Post("test-xml");
        AllowAnonymous();
        Description(x => x
            .Accepts<Request>("application/xml")
            .Produces<Response>(200, "application/xml"),
        clearDefaults: true);
    }

    public override async Task HandleAsync(Request r, CancellationToken c)
    {
        var response = new Response
        {
            FullName = r.FirstName + " " + r.LastName
        };
        await this.SendXMLAsync(response);
    }
}

Thx, this helped a lot with XML responses/requests!