AccessTokenHandler does not support sync methods

[codingbott]

Which version of Duende.AccessTokenManagement are you using?
3.0.0

Which version of .NET are you using?
6

Describe the bug

I'm try to use the OpenTelemetryClient from dotnet together with the AccessTokenManagement.

Setup like this:

builder.Services.AddClientCredentialsTokenManagement().AddClient("Token.Client.OtelAuditLogger", options =>
                {
                   // options setup here with crediential etc.
                });

            builder.Services
                .AddClientCredentialsHttpClient("Http.Client.OtelAuditLogger", "Token.Client.OtelAuditLogger");

Later on in my implementation I pass the IHttpClientFactory in my class:

    public AuditLogger(IHttpClientFactory httpClientFactory)
    {
        string plantShort = "tc5ot";
        string teamName = "BackboneInfra";
        string applicationName = "OtelDemoApp";

        var loggerFactory = LoggerFactory.Create(builder =>
        {
            builder.SetMinimumLevel(LogLevel.Trace);
            builder.AddOpenTelemetry(logging =>
            {
                logging.AddOtlpExporter(otlpOptions =>
                {
                    otlpOptions.Endpoint = new Uri(OtlpHttp);
                    otlpOptions.Protocol = OtlpExportProtocol.HttpProtobuf;

                    otlpOptions.HttpClientFactory = () =>
                    {
                        var httpClient = httpClientFactory.CreateClient("Http.Client.OtelAuditLogger");
                        httpClient.BaseAddress = new Uri(OtlpHttp);

                        // this lines test if the AccessTokenManagement is bound
                        // using SEND does NOT request a token and SEND is used by OTEL log exporter 
                        var failingGettingToken = httpClient.Send(new HttpRequestMessage());
                        // compared with SendAsync: This does request a token
                        var successGettingToken = httpClient.SendAsync(new HttpRequestMessage());

                        return httpClient;
                    };
                });
            });
        });

        var _logger = loggerFactory.CreateLogger<AuditLogger>();
        _logger.Log(LogLevel.Critical, "Hello World");
    }

To Reproduce

See the source above. Where the httpClient is created I'm doing a send which does not request tokens. I saw that in the logs.
When I call SendAsync, then the lib is requesting a token.

Expected behavior

Also Send method will request a token.

Additional context

src/Duende.AccessTokenManagement/AccessTokenHandler.cs

Does not override the Send method, but SendAync only.

[AndersAbel]

It looks like Send was added in .NET 5, while SendAsync has been around since .NET Core 1.0 (and .NET Framework 4.5), so I guess the reason is that when the code was initially written, there was no Send method.

I'll transfer this issue to our FOSS repository (the home for Duende.AccessTokenManagement) for handling.