Overwrite ConnectionInfo.LocalPort in Tests?

[schmitch]

Hello,

we are currently starting out with testing. We want to write some new end-to-end tests, however we stumbled upon a major roadblock.
currently we fork our middleware via ConnectionInfo.LocalPort like this:

bool AppACondition(HttpContext ctx) => ctx.Connection.LocalPort == 5012;
bool AppBCondition(HttpContext ctx) => ctx.Connection.LocalPort is 5007 or 5010 or 5011;
        app.MapWhen(
            AppACondition,
            offer => ConfigureAppA(offer, env));

        app.MapWhen(
            AppBCondition,
            other => ConfigureAppB(other, env, antiforgery));

However the local port with the WebApplicationFactory test is always zero. We tried to overwrite it like that:

    protected override TestServer CreateServer(IWebHostBuilder builder)
    {
        var features = new FeatureCollection();
        features.Set<IHttpConnectionFeature>(new HttpConnectionFeature
        {
            LocalPort = 5010,
        });
        return new (builder, features);
    }

however it does not look like the connectionfeature gets picked up by the ClientHandler is there any way to do that?