JsonReaderException using FromClaim with latest FastEndpoints (4.2 - 4.3.0-beta2)

Expected Behavior

To retrieve user data from the parsed request, which is retrieving claims as request.

Actual Behavior

{
  "status": "Internal Server Error!",
  "code": 500,
  "reason": "'M' is an invalid start of a value. Path: $ | LineNumber: 0 | BytePositionInLine: 0.",
  "note": "See application log for stack trace."
}

Steps to Reproduce the Problem

1. As package, use FastEndpoints 4.2.0 or highest (at time of writing: 4.3.0-beta2)
2. Write an Endpoint with requests using FromClaim and a non-FromClaimresponse (same parameters)
3. Write the endpoint
4. You get the exception below

public class UserEndpointRequest
{
	[FromClaim(CustomClaimTypes.UserId)]
	public Guid UserId { get; init; }
	[FromClaim(CustomClaimTypes.Name)]
	public string Name { get; init; } = string.Empty;
	[FromClaim(CustomClaimTypes.Email)]
	public string Email { get; init; } = string.Empty;
	//todo fromClaims can not get multi claims of the same type
	[FromClaim(CustomClaimTypes.Roles)]
	public List<string> Roles { get; init; } = new List<string>();
}

public class UserEndpoint : EndpointWithMapping<UserEndpointRequest, UserEndpointResponse, UserEndpointResponse>
{
	public override void Configure()
	{
		Verbs(Http.GET);
		Routes("/user");
		Description(x => x.WithName("user"));
	}

	public override async Task HandleAsync(UserEndpointRequest req, CancellationToken ct) => await SendAsync(MapToEntity(req), cancellation: ct);

	public override UserEndpointResponse MapToEntity(UserEndpointRequest r) =>
		new()
		{
			UserId = r.UserId,
			Name = r.Name,
			Email = r.Email,
			Roles = HttpContext.User.Claims.Where(c => c.Type == CustomClaimTypes.Roles && c.Value.StartsWith("Admin")).Select(c => c.Value)
		};
}

Exception thrown: 'System.Text.Json.JsonException' in System.Private.CoreLib.dll: ''M' is an invalid start of a value. Path: $ | LineNumber: 0 | BytePositionInLine: 0.'
 Inner exceptions found, see $exception in variables window for more details.
 Innermost exception 	 System.Text.Json.JsonReaderException : 'M' is an invalid start of a value. LineNumber: 0 | BytePositionInLine: 0.
   at System.Text.Json.ThrowHelper.ThrowJsonReaderException(Utf8JsonReader& json, ExceptionResource resource, Byte nextByte, ReadOnlySpan`1 bytes)
   at System.Text.Json.Utf8JsonReader.ConsumeValue(Byte marker)
   at System.Text.Json.Utf8JsonReader.ReadFirstToken(Byte first)
   at System.Text.Json.Utf8JsonReader.ReadSingleSegment()
   at System.Text.Json.Utf8JsonReader.Read()
   at System.Text.Json.Serialization.JsonConverter`1.ReadCore(Utf8JsonReader& reader, JsonSerializerOptions options, ReadStack& state)

at System.Text.Json.ThrowHelper.ReThrowWithPath(ReadStack& state, JsonReaderException ex)
   at System.Text.Json.Serialization.JsonConverter`1.ReadCore(Utf8JsonReader& reader, JsonSerializerOptions options, ReadStack& state)
   at System.Text.Json.Serialization.JsonConverter`1.ReadCoreAsObject(Utf8JsonReader& reader, JsonSerializerOptions options, ReadStack& state)
   at System.Text.Json.JsonSerializer.ReadFromSpan[TValue](ReadOnlySpan`1 utf8Json, JsonTypeInfo jsonTypeInfo, Nullable`1 actualByteCount)
   at System.Text.Json.JsonSerializer.ReadFromSpan[TValue](ReadOnlySpan`1 json, JsonTypeInfo jsonTypeInfo)
   at System.Text.Json.JsonSerializer.Deserialize(String json, Type returnType, JsonSerializerOptions options)
   at FastEndpoints.ReflectionExtensions.<>c__DisplayClass8_0.<GetCompiledValueParser>b__3(Object input)
   at FastEndpoints.Endpoint`2.BindUserClaims(TRequest req, IEnumerable`1 claims, List`1 failures)
   at FastEndpoints.Endpoint`2.BindToModel(HttpContext ctx, List`1 failures, JsonSerializerContext serializerCtx, Boolean dontAutoBindForm, CancellationToken cancellation)
   at FastEndpoints.Endpoint`2.ExecAsync(HttpContext ctx, EndpointDefinition endpoint, CancellationToken cancellation)
   at Microsoft.AspNetCore.Authorization.Policy.AuthorizationMiddlewareResultHandler.HandleAsync(RequestDelegate next, HttpContext context, AuthorizationPolicy policy, PolicyAuthorizationResult authorizeResult)
   at Microsoft.AspNetCore.Authorization.AuthorizationMiddleware.Invoke(HttpContext context)
   at 

[EelcoLos]

Awesome,will check tomorrow morning first thing! Have a fine evening, sir!

[dj-nitehawk]

fixed in v4.3.0-beta3

the following now works:

public class Request
{
    public string IdNumber { get; set; }

    [FromClaim("username")]
    public string UserName { get; set; }

    [FromClaim(ClaimTypes.Role)]
    public IEnumerable<string> Roles { get; init; }

}

public class Test : Endpoint<Request>
{
    public override void Configure()
    {
        Get("test");
        Roles("Admin");
        Claims("username");
    }

    public override async Task HandleAsync(Request req, CancellationToken ct)
    {
        await SendAsync(req);
    }
}

public class Login : EndpointWithoutRequest
{
    public override void Configure()
    {
        Get("login");
        AllowAnonymous();
    }

    public override Task HandleAsync(CancellationToken ct)
    {
        Response = JWTBearer.CreateToken(
            signingKey: "xxxxxxxxxxxxxxxx",
            roles: new[] { "Admin", "Manager" },
            claims: ("username", "marko polo"));

        return Task.CompletedTask;
    }
}