SlipItIn/SlipItIn.Server.Tests/GameHubTests.cs

using Microsoft.AspNetCore.SignalR;
using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.Logging.Abstractions;
using Moq;
using SlipItIn.Server.Data;
using SlipItIn.Server.Hubs;
using SlipItIn.Server.Services;
using SlipItIn.Shared.DTOs;
using SlipItIn.Shared.Models;
using System.Security.Claims;

namespace SlipItIn.Server.Tests;

/// <summary>
/// Tests für den GameHub mit gemocktem IGameService und gemockten SignalR-Abhängigkeiten.
/// Echte DB (InMemory) wird nur für die Validierungs-Methoden des Hubs verwendet.
/// </summary>
public class GameHubTests
{
    private readonly IDbContextFactory<SlipItInDbContext> _factory = TestDbHelper.CreateFactory();
    private readonly Mock<IGameService> _gameService = new();
    private readonly Mock<IGroupManager> _groups = new();
    private readonly Mock<IHubCallerClients> _clients = new();
    private readonly Mock<ISingleClientProxy> _callerProxy = new();
    private readonly Mock<IClientProxy> _groupProxy = new();
    private readonly Mock<ISingleClientProxy> _clientProxy = new();
    private readonly GameHub _hub;

    private const string ConnectionId = "test-connection-id";
    private int _userId = 1;

    public GameHubTests()
    {
        _clients.Setup(c => c.Caller).Returns(_callerProxy.Object);
        _clients.Setup(c => c.Group(It.IsAny<string>())).Returns(_groupProxy.Object);
        _clients.Setup(c => c.Client(It.IsAny<string>())).Returns(_clientProxy.Object);

        _hub = new GameHub(_gameService.Object, _factory, NullLogger<GameHub>.Instance);
        SetupContext();
    }

    private void SetupContext()
    {
        var identity = new ClaimsIdentity([new Claim(ClaimTypes.NameIdentifier, _userId.ToString())], "TestAuth");
        var context = new Mock<HubCallerContext>();
        context.Setup(c => c.ConnectionId).Returns(ConnectionId);
        context.Setup(c => c.User).Returns(new ClaimsPrincipal(identity));
        _hub.Context = context.Object;
        _hub.Clients = _clients.Object;
        _hub.Groups = _groups.Object;
    }

    private void WithoutAuth()
    {
        var context = new Mock<HubCallerContext>();
        context.Setup(c => c.ConnectionId).Returns(ConnectionId);
        context.Setup(c => c.User).Returns((ClaimsPrincipal?)null);
        _hub.Context = context.Object;
    }

    private static string? ErrorMessageOf(Mock<ISingleClientProxy> proxy)
    {
        // Die Aufrufe kommen als SendCoreAsync(string, object?[]) mit dem Payload in args[1] rein.
        var invocation = proxy.Invocations.FirstOrDefault(i => i.Arguments.Count >= 2 && i.Arguments[0] is string m && m == "Error");
        if (invocation == null) return null;
        var payload = invocation.Arguments[1];
        // Payload kann ein anonymes Objekt sein oder ein object?[] mit einem anonymen Objekt drin.
        if (payload is object?[] arr && arr.Length > 0) payload = arr[0];
        return payload?.GetType().GetProperty("Message")?.GetValue(payload) as string;
    }

    private Game SeedGameWithPlayers(params (User user, string? connId)[] players)
    {
        using var db = _factory.CreateDbContext();
        var game = new Game { LobbyCode = "ABC123", HostId = players[0].user.Id, Status = GameStatus.Lobby };
        db.Games.Add(game);
        foreach (var (user, connId) in players)
        {
            db.Players.Add(new Player { UserId = user.Id, Game = game, ConnectionId = connId });
        }
        db.SaveChanges();
        return game;
    }

    private (User user, Player player) SeedUserWithPlayer(Game game)
    {
        using var db = _factory.CreateDbContext();
        var user = TestDbHelper.SeedUser(db, Guid.NewGuid().ToString("N")[..8], Guid.NewGuid().ToString("N")[..8] + "@t.local");
        var player = new Player { UserId = user.Id, GameId = game.Id };
        db.Players.Add(player);
        db.SaveChanges();
        return (user, player);
    }

    // ---------- CreateLobby ----------

    [Fact]
    public async Task CreateLobby_AddsCallerToGroupAndSendsLobbyCreated()
    {
        using var db = _factory.CreateDbContext();
        var user = TestDbHelper.SeedUser(db);
        _userId = user.Id;
        SetupContext();

        var game = new Game { Id = 7, LobbyCode = "XYZ789", HostId = user.Id };
        _gameService.Setup(s => s.CreateGameAsync(user.Id, ConnectionId)).ReturnsAsync(game);

        await _hub.CreateLobby();

        _groups.Verify(g => g.AddToGroupAsync(ConnectionId, "XYZ789", default), Times.Once);
        _callerProxy.Verify(p => p.SendCoreAsync("LobbyCreated", It.Is<object?[]>(a => a.Length == 1), default), Times.Once);
    }

    [Fact]
    public async Task CreateLobby_SendsUnauthorized_WhenNotAuthenticated()
    {
        WithoutAuth();

        await _hub.CreateLobby();

        Assert.Equal("Unauthorized", ErrorMessageOf(_callerProxy));
    }

    [Fact]
    public async Task CreateLobby_SendsGenericError_WhenServiceThrows()
    {
        _gameService.Setup(s => s.CreateGameAsync(It.IsAny<int>(), It.IsAny<string?>()))
            .ThrowsAsync(new InvalidOperationException("Host not found"));

        await _hub.CreateLobby();

        Assert.Equal("An error occurred while creating the lobby.", ErrorMessageOf(_callerProxy));
    }

    // ---------- JoinLobby ----------

    [Fact]
    public async Task JoinLobby_AddsToGroupAndBroadcastsPlayerJoined()
    {
        using var db = _factory.CreateDbContext();
        var user = TestDbHelper.SeedUser(db);
        _userId = user.Id;
        SetupContext();

        var game = new Game { Id = 3, LobbyCode = "JOIN42", HostId = 99 };
        _gameService.Setup(s => s.JoinGameAsync("JOIN42", user.Id, ConnectionId)).ReturnsAsync(game);
        _gameService.Setup(s => s.GetGameStateAsync(game.Id)).ReturnsAsync(new GameStateDto { GameId = 3 });

        await _hub.JoinLobby("JOIN42");

        _groups.Verify(g => g.AddToGroupAsync(ConnectionId, "JOIN42", default), Times.Once);
        _groupProxy.Verify(p => p.SendCoreAsync("PlayerJoined", It.IsAny<object?[]>(), default), Times.Once);
    }

    [Fact]
    public async Task JoinLobby_SendsUnauthorized_WhenNotAuthenticated()
    {
        WithoutAuth();

        await _hub.JoinLobby("ANY");

        Assert.Equal("Unauthorized", ErrorMessageOf(_callerProxy));
    }

    [Fact]
    public async Task JoinLobby_SendsServiceMessage_WhenGameFullOrStarted()
    {
        _gameService.Setup(s => s.JoinGameAsync(It.IsAny<string>(), It.IsAny<int>(), It.IsAny<string?>()))
            .ThrowsAsync(new InvalidOperationException("Game is full"));

        await _hub.JoinLobby("FULL1");

        Assert.Equal("Game is full", ErrorMessageOf(_callerProxy));
    }

    [Fact]
    public async Task JoinLobby_SendsGenericError_WhenUnexpectedException()
    {
        _gameService.Setup(s => s.JoinGameAsync(It.IsAny<string>(), It.IsAny<int>(), It.IsAny<string?>()))
            .ThrowsAsync(new Exception("boom"));

        await _hub.JoinLobby("ANY");

        Assert.Equal("An error occurred while joining the lobby.", ErrorMessageOf(_callerProxy));
    }

    // ---------- PlayerReady ----------

    [Fact]
    public async Task PlayerReady_BroadcastsGameState_WhenValid()
    {
        using var db = _factory.CreateDbContext();
        var user = TestDbHelper.SeedUser(db);
        _userId = user.Id;
        SetupContext();
        var game = SeedGameWithPlayers((user, ConnectionId));
        var player = db.Players.Single(p => p.GameId == game.Id);

        _gameService.Setup(s => s.SetPlayerReadyAsync(game.Id, player.Id))
            .ReturnsAsync(new Game { Id = game.Id, LobbyCode = game.LobbyCode });
        _gameService.Setup(s => s.GetGameStateAsync(game.Id)).ReturnsAsync(new GameStateDto { GameId = game.Id });

        await _hub.PlayerReady(game.Id, player.Id);

        _groupProxy.Verify(p => p.SendCoreAsync("GameStateUpdated", It.IsAny<object?[]>(), default), Times.Once);
    }

    [Fact]
    public async Task PlayerReady_SendsError_WhenPlayerBelongsToOtherUser()
    {
        using var db = _factory.CreateDbContext();
        var user = TestDbHelper.SeedUser(db, "me", "me@t.local");
        var other = TestDbHelper.SeedUser(db, "other", "other@t.local");
        _userId = user.Id;
        SetupContext();
        var game = SeedGameWithPlayers((other, null));
        var otherPlayer = db.Players.Single(p => p.GameId == game.Id);

        await _hub.PlayerReady(game.Id, otherPlayer.Id);

        Assert.Equal("Player does not belong to authenticated user", ErrorMessageOf(_callerProxy));
    }

    [Fact]
    public async Task PlayerReady_SendsGenericError_WhenServiceThrows()
    {
        using var db = _factory.CreateDbContext();
        var user = TestDbHelper.SeedUser(db);
        _userId = user.Id;
        SetupContext();
        var game = SeedGameWithPlayers((user, ConnectionId));
        var player = db.Players.Single(p => p.GameId == game.Id);

        _gameService.Setup(s => s.SetPlayerReadyAsync(It.IsAny<int>(), It.IsAny<int>()))
            .ThrowsAsync(new InvalidOperationException("Player not found"));

        await _hub.PlayerReady(game.Id, player.Id);

        Assert.Equal("An error occurred while setting player status.", ErrorMessageOf(_callerProxy));
    }

    // ---------- StartGame ----------

    [Fact]
    public async Task StartGame_BroadcastsGameStarted_AndSendsHandsToEachPlayer()
    {
        using var db = _factory.CreateDbContext();
        var host = TestDbHelper.SeedUser(db, "host", "host@t.local");
        _userId = host.Id;
        SetupContext();
        var game = SeedGameWithPlayers((host, "conn-host"));
        var (_, otherPlayer) = SeedUserWithPlayer(game);
        using (var db2 = _factory.CreateDbContext())
        {
            db2.Players.Single(p => p.Id == otherPlayer.Id).ConnectionId = "conn-other";
            db2.SaveChanges();
        }

        _gameService.Setup(s => s.StartGameAsync(game.Id)).ReturnsAsync(new Game { Id = game.Id, LobbyCode = game.LobbyCode });
        _gameService.Setup(s => s.DealCardsAsync(game.Id)).ReturnsAsync([
            new PlayerCard { PlayerId = game.Players.First().Id },
            new PlayerCard { PlayerId = otherPlayer.Id }
        ]);
        _gameService.Setup(s => s.GetPlayerHandAsync(It.IsAny<int>())).ReturnsAsync((int pid) => new PlayerHandDto { PlayerId = pid });

        await _hub.StartGame(game.Id);

        _groupProxy.Verify(p => p.SendCoreAsync("GameStarted", It.IsAny<object?[]>(), default), Times.Once);
        // Beide Spieler erhalten ihre Hand (über Clients.Client)
        _clients.Verify(c => c.Client("conn-host"), Times.Once);
        _clients.Verify(c => c.Client("conn-other"), Times.Once);
        _clientProxy.Verify(p => p.SendCoreAsync("PlayerHandUpdated", It.IsAny<object?[]>(), default), Times.Exactly(2));
    }

    [Fact]
    public async Task StartGame_SendsHostOnlyError_WhenCallerIsNotHost()
    {
        using var db = _factory.CreateDbContext();
        var host = TestDbHelper.SeedUser(db, "host", "host@t.local");
        var notHost = TestDbHelper.SeedUser(db, "not", "not@t.local");
        _userId = notHost.Id;
        SetupContext();
        var game = SeedGameWithPlayers((host, null), (notHost, null));

        await _hub.StartGame(game.Id);

        Assert.Equal("Only the host can start the game.", ErrorMessageOf(_callerProxy));
    }

    [Fact]
    public async Task StartGame_SendsGenericError_WhenServiceThrows()
    {
        using var db = _factory.CreateDbContext();
        var host = TestDbHelper.SeedUser(db);
        _userId = host.Id;
        SetupContext();
        var game = SeedGameWithPlayers((host, null));

        _gameService.Setup(s => s.StartGameAsync(It.IsAny<int>())).ThrowsAsync(new Exception("boom"));

        await _hub.StartGame(game.Id);

        Assert.Equal("An error occurred while starting the game.", ErrorMessageOf(_callerProxy));
    }

    // ---------- SubmitSlip ----------

    [Fact]
    public async Task SubmitSlip_BroadcastsSlipSubmitted_WhenValid()
    {
        using var db = _factory.CreateDbContext();
        var user = TestDbHelper.SeedUser(db);
        _userId = user.Id;
        SetupContext();
        var game = SeedGameWithPlayers((user, ConnectionId));
        var player = db.Players.Single(p => p.GameId == game.Id);

        _gameService.Setup(s => s.SubmitSlipAsync(game.Id, player.Id, 55)).ReturnsAsync(true);
        _gameService.Setup(s => s.GetGameAsync(game.Id)).ReturnsAsync(new Game { Id = game.Id, LobbyCode = game.LobbyCode });

        await _hub.SubmitSlip(game.Id, player.Id, 55);

        _groupProxy.Verify(p => p.SendCoreAsync("SlipSubmitted", It.IsAny<object?[]>(), default), Times.Once);
    }

    [Fact]
    public async Task SubmitSlip_SendsError_WhenPlayerNotOwnedByUser()
    {
        using var db = _factory.CreateDbContext();
        var user = TestDbHelper.SeedUser(db, "me", "me@t.local");
        var other = TestDbHelper.SeedUser(db, "other", "other@t.local");
        _userId = user.Id;
        SetupContext();
        var game = SeedGameWithPlayers((other, null));
        var otherPlayer = db.Players.Single(p => p.GameId == game.Id);

        await _hub.SubmitSlip(game.Id, otherPlayer.Id, 1);

        Assert.Equal("Player does not belong to authenticated user", ErrorMessageOf(_callerProxy));
    }

    [Fact]
    public async Task SubmitSlip_SendsGenericError_WhenServiceThrows()
    {
        using var db = _factory.CreateDbContext();
        var user = TestDbHelper.SeedUser(db);
        _userId = user.Id;
        SetupContext();
        var game = SeedGameWithPlayers((user, ConnectionId));
        var player = db.Players.Single(p => p.GameId == game.Id);

        _gameService.Setup(s => s.SubmitSlipAsync(It.IsAny<int>(), It.IsAny<int>(), It.IsAny<int>()))
            .ThrowsAsync(new InvalidOperationException("Card not found"));

        await _hub.SubmitSlip(game.Id, player.Id, 999);

        Assert.Equal("An error occurred while submitting slip.", ErrorMessageOf(_callerProxy));
    }

    // ---------- ChallengeSlip ----------

    [Fact]
    public async Task ChallengeSlip_BroadcastsAndNotifiesTargetPlayer()
    {
        using var db = _factory.CreateDbContext();
        var challenger = TestDbHelper.SeedUser(db, "ch", "ch@t.local");
        _userId = challenger.Id;
        SetupContext();
        var game = SeedGameWithPlayers((challenger, ConnectionId));
        var (_, targetPlayer) = SeedUserWithPlayer(game);
        using (var db2 = _factory.CreateDbContext())
        {
            db2.Players.Single(p => p.Id == targetPlayer.Id).ConnectionId = "conn-target";
            db2.SaveChanges();
        }
        var challengerPlayer = db.Players.Single(p => p.UserId == challenger.Id);

        _gameService.Setup(s => s.CreateChallengeAsync(game.Id, challengerPlayer.Id, 42))
            .ReturnsAsync(new SlipChallenge
            {
                Id = 1,
                ChallengingPlayerId = challengerPlayer.Id,
                TargetPlayerId = targetPlayer.Id,
                TargetCardId = 42,
                Status = ChallengeStatus.Pending
            });
        _gameService.Setup(s => s.GetGameAsync(game.Id)).ReturnsAsync(new Game { Id = game.Id, LobbyCode = game.LobbyCode });

        await _hub.ChallengeSlip(game.Id, challengerPlayer.Id, 42);

        _groupProxy.Verify(p => p.SendCoreAsync("SlipChallenged", It.IsAny<object?[]>(), default), Times.Once);
        _clients.Verify(c => c.Client("conn-target"), Times.Once);
        _clientProxy.Verify(p => p.SendCoreAsync("ChallengeReceived", It.IsAny<object?[]>(), default), Times.Once);
    }

    [Fact]
    public async Task ChallengeSlip_SendsError_WhenPlayerNotOwnedByUser()
    {
        using var db = _factory.CreateDbContext();
        var user = TestDbHelper.SeedUser(db, "me", "me@t.local");
        var other = TestDbHelper.SeedUser(db, "other", "other@t.local");
        _userId = user.Id;
        SetupContext();
        var game = SeedGameWithPlayers((other, null));
        var otherPlayer = db.Players.Single(p => p.GameId == game.Id);

        await _hub.ChallengeSlip(game.Id, otherPlayer.Id, 1);

        Assert.Equal("Player does not belong to authenticated user", ErrorMessageOf(_callerProxy));
    }

    [Fact]
    public async Task ChallengeSlip_SendsGenericError_WhenServiceThrows()
    {
        using var db = _factory.CreateDbContext();
        var user = TestDbHelper.SeedUser(db);
        _userId = user.Id;
        SetupContext();
        var game = SeedGameWithPlayers((user, ConnectionId));
        var player = db.Players.Single(p => p.GameId == game.Id);

        _gameService.Setup(s => s.CreateChallengeAsync(It.IsAny<int>(), It.IsAny<int>(), It.IsAny<int>()))
            .ThrowsAsync(new InvalidOperationException("No active round found"));

        await _hub.ChallengeSlip(game.Id, player.Id, 1);

        Assert.Equal("An error occurred while challenging slip.", ErrorMessageOf(_callerProxy));
    }

    // ---------- ResolveChallenge ----------

    [Fact]
    public async Task ResolveChallenge_BroadcastsAndUpdatesHands_WhenTargetResolves()
    {
        using var db = _factory.CreateDbContext();
        var target = TestDbHelper.SeedUser(db, "target", "target@t.local");
        _userId = target.Id;
        SetupContext();
        var game = SeedGameWithPlayers((target, "conn-target"));
        var targetPlayer = db.Players.Single(p => p.UserId == target.Id);
        var (_, challengingPlayer) = SeedUserWithPlayer(game);
        using (var db2 = _factory.CreateDbContext())
        {
            db2.Players.Single(p => p.Id == challengingPlayer.Id).ConnectionId = "conn-challenger";
            var round = new GameRound { GameId = game.Id, RoundNumber = 1, Status = RoundStatus.Active };
            db2.GameRounds.Add(round);
            var phrase = TestDbHelper.SeedPhrases(db2, 1).Single();
            var card = new PlayerCard { PlayerId = targetPlayer.Id, PhraseId = phrase.Id, GameRoundId = round.Id };
            db2.PlayerCards.Add(card);
            db2.SlipChallenges.Add(new SlipChallenge
            {
                Id = 77,
                GameRoundId = round.Id,
                ChallengingPlayerId = challengingPlayer.Id,
                TargetPlayerId = targetPlayer.Id,
                TargetCardId = card.Id,
                Status = ChallengeStatus.Pending
            });
            db2.SaveChanges();
        }

        _gameService.Setup(s => s.ResolveChallengeAsync(77, true))
            .ReturnsAsync(new SlipChallenge
            {
                Id = 77,
                GameRound = new GameRound { GameId = game.Id },
                ChallengingPlayerId = challengingPlayer.Id,
                TargetPlayerId = targetPlayer.Id,
                Status = ChallengeStatus.Approved
            });
        _gameService.Setup(s => s.GetGameAsync(game.Id)).ReturnsAsync(new Game { Id = game.Id, LobbyCode = game.LobbyCode });
        _gameService.Setup(s => s.GetPlayerHandAsync(It.IsAny<int>())).ReturnsAsync((int pid) => new PlayerHandDto { PlayerId = pid });

        await _hub.ResolveChallenge(77, true);

        _groupProxy.Verify(p => p.SendCoreAsync("ChallengeResolved", It.IsAny<object?[]>(), default), Times.Once);
        _clientProxy.Verify(p => p.SendCoreAsync("PlayerHandUpdated", It.IsAny<object?[]>(), default), Times.Exactly(2));
    }

    [Fact]
    public async Task ResolveChallenge_SendsError_WhenCallerIsNotTarget()
    {
        using var db = _factory.CreateDbContext();
        var target = TestDbHelper.SeedUser(db, "target", "target@t.local");
        var notTarget = TestDbHelper.SeedUser(db, "not", "not@t.local");
        _userId = notTarget.Id;
        SetupContext();
        var game = SeedGameWithPlayers((target, null));
        var targetPlayer = db.Players.Single(p => p.UserId == target.Id);
        using (var db2 = _factory.CreateDbContext())
        {
            db2.SlipChallenges.Add(new SlipChallenge
            {
                Id = 78,
                GameRoundId = 1,
                ChallengingPlayerId = 1,
                TargetPlayerId = targetPlayer.Id,
                TargetCardId = 1,
                Status = ChallengeStatus.Pending
            });
            db2.SaveChanges();
        }

        await _hub.ResolveChallenge(78, true);

        Assert.Equal("Only the accused player can resolve this challenge", ErrorMessageOf(_callerProxy));
    }

    [Fact]
    public async Task ResolveChallenge_SendsMessage_WhenChallengeNotFound()
    {
        using var db = _factory.CreateDbContext();
        var user = TestDbHelper.SeedUser(db);
        _userId = user.Id;
        SetupContext();

        await _hub.ResolveChallenge(999, true);

        Assert.Equal("Challenge not found", ErrorMessageOf(_callerProxy));
    }

    // ---------- RequestGameState ----------

    [Fact]
    public async Task RequestGameState_SendsStateToCaller_WhenParticipant()
    {
        using var db = _factory.CreateDbContext();
        var user = TestDbHelper.SeedUser(db);
        _userId = user.Id;
        SetupContext();
        SeedGameWithPlayers((user, ConnectionId));
        var gameId = db.Games.Single().Id;

        _gameService.Setup(s => s.GetGameStateAsync(gameId)).ReturnsAsync(new GameStateDto { GameId = gameId });

        await _hub.RequestGameState(gameId);

        _callerProxy.Verify(p => p.SendCoreAsync("GameStateUpdated", It.IsAny<object?[]>(), default), Times.Once);
    }

    [Fact]
    public async Task RequestGameState_SendsError_WhenNotParticipant()
    {
        using var db = _factory.CreateDbContext();
        var user = TestDbHelper.SeedUser(db);
        var other = TestDbHelper.SeedUser(db, "other", "other@t.local");
        _userId = user.Id;
        SetupContext();
        SeedGameWithPlayers((other, null));
        var gameId = db.Games.Single().Id;

        await _hub.RequestGameState(gameId);

        Assert.Equal("User is not part of this game", ErrorMessageOf(_callerProxy));
    }

    [Fact]
    public async Task RequestGameState_SendsGenericError_WhenServiceThrows()
    {
        using var db = _factory.CreateDbContext();
        var user = TestDbHelper.SeedUser(db);
        _userId = user.Id;
        SetupContext();
        SeedGameWithPlayers((user, ConnectionId));
        var gameId = db.Games.Single().Id;

        _gameService.Setup(s => s.GetGameStateAsync(It.IsAny<int>())).ThrowsAsync(new Exception("boom"));

        await _hub.RequestGameState(gameId);

        Assert.Equal("An error occurred while requesting game state.", ErrorMessageOf(_callerProxy));
    }

    // ---------- OnConnectedAsync ----------

    [Fact]
    public async Task OnConnectedAsync_StoresConnectionId_WhenUserInActiveGame()
    {
        using var db = _factory.CreateDbContext();
        var user = TestDbHelper.SeedUser(db);
        _userId = user.Id;
        SetupContext();
        SeedGameWithPlayers((user, null));

        await _hub.OnConnectedAsync();

        using var verify = _factory.CreateDbContext();
        Assert.Equal(ConnectionId, verify.Players.Single(p => p.UserId == user.Id).ConnectionId);
    }

    [Fact]
    public async Task OnConnectedAsync_DoesNotThrow_WhenNotAuthenticated()
    {
        WithoutAuth();

        await _hub.OnConnectedAsync(); // darf nicht werfen
    }

    // ---------- OnDisconnectedAsync ----------

    [Fact]
    public async Task OnDisconnectedAsync_Completes()
    {
        await _hub.OnDisconnectedAsync(null);
    }
}