ASP NET Core SignalR OnDisconnectedAsync not firing with hub [Authorized]

Question

.net core 2.1

Hub code:

[Authorize]    
public class OnlineHub : Hub
{
public override async System.Threading.Tasks.Task OnConnectedAsync()
{
    int userId = Context.UserIdentifier;
    await base.OnConnectedAsync();
}

[AllowAnonymous]
public override async System.Threading.Tasks.Task OnDisconnectedAsync(Exception exception)
{
    var b = Context.ConnectionId;

    await base.OnDisconnectedAsync(exception);

}

Client code:

$(document).ready(() => {
        let token = "token";
        const connection = new signalR.HubConnectionBuilder()
            .withUrl("https://localhost:44343/online", { accessTokenFactory: () => token })
            .configureLogging(signalR.LogLevel.Debug)
            .build();

    connection.start().catch(err => console.error(err.toString()));
    });

Without [Authorize] all works fine, except Context.UserIdentifier in OnConnectedAsync, and it's explainable, but... with [Authorize] attribute on Hub class, OnConnectedAsync start working and OnDisconnected not fires at all, including 30sec timeout (by default).

Any ideas?

Answer 1

If you have a debugger attached and close the client by closing the browser tab, then you'll never observe OnDisconnectedAsync being fired. This is because SignalR check if a debugger is attached and don't trigger certain timeouts in order to making debugging easier. If you close by calling stop on the client then you should see OnDisconnectedAsync called.

Answer 2

for blazor implement this code

@implements IAsyncDisposable

and paste this func. to code

public async ValueTask DisposeAsync()
{
    if (hubConnection is not null)
    {
        await hubConnection.DisposeAsync();
    }
}