How to write integration test for SignalR

Question

I use Signalr in my Web API. How to perform integration testing on it? I do not want to mock Hub I want to work on real instance of connection and check the results.

Currently I have something like this. I can not establish connection to my hub

[Fact]
 public async Task Should_CreateUser()
 {
     using var client = new WebApplicationFactory<Program>().CreateClient();

     var handler = new HttpClientHandler();
     handler.ServerCertificateCustomValidationCallback = HttpClientHandler.DangerousAcceptAnyServerCertificateValidator;
     var connection = new HubConnectionBuilder()
         .WithUrl(client.BaseAddress + "/auction-hub", options =>
         {
             options.HttpMessageHandlerFactory = _ => handler;
         })
         .Build();

     await connection.StartAsync();

 }

Hub:

namespace Bidnest.Application.Hubs
{
    public class AuctionHub : Hub<IAuctionHub>
    {

        public override async Task OnConnectedAsync()
        {
            await Clients.All.UserWasOutbid($"Hey {Context.UserIdentifier}");
        }
    }
}

Answer 1

My solution:

public class UserEventsTest : BaseIntegrationTest
{
    private readonly IntegrationTestWebAppFactory _factory;

    public UserEventsTest(IntegrationTestWebAppFactory factory) : base(factory)
    {
        _factory = factory;
    }

    [Fact]
    public async Task Should_CreateUser()
    {
        var client = _factory.CreateClient();
        var server = _factory.Server;
        var result = await client.GetAsync("/WeatherForecast");
        result.EnsureSuccessStatusCode();

        var connection = new HubConnectionBuilder()
            .WithUrl("wss://localhost" + "/auction-hub", options =>
            {
                options.HttpMessageHandlerFactory = _ => server.CreateHandler();
            })
            .Build();

        await connection.StartAsync();

    }
}

This line use IntegrationTestWebAppFactory

var client = _factory.CreateClient();

which is an abstraction of

new WebApplicationFactory<Program>().CreateClient()

So if you do not need abstraction you can go with this approach. It creates application and expose endpoints.

Here I make sure standard HTTP requests are fine

var result = await client.GetAsync("/WeatherForecast");
result.EnsureSuccessStatusCode();

And here I connect to my hub mapped in Program.cs

var connection = new HubConnectionBuilder()
            .WithUrl("wss://localhost" + "/auction-hub", options =>
            {
                options.HttpMessageHandlerFactory = _ => server.CreateHandler();
            })
            .Build();

        await connection.StartAsync();