Merge pull request #28 from HueByte/dev_fix_ghost_channel_on_join

fix: ghost channel when trying to join a channel that doesn't exist

docs/changelog/v0.2.8.md

@@ -15,6 +15,7 @@
 - Fix thread safety — `_channelUsers` presence cache now protected by `Lock` to prevent races between SignalR events and background fetches
 - Fix `@mention` regex matching email addresses and `#channel` regex matching hex colors / issue numbers — both now use lookbehind and letter-requirement guards
 - Fix `ParseThemeColor` accepting non-hex characters — now validates `[0-9a-fA-F]` digits
+- Fix ghost channel when trying to join a channel that doesn't exist
 
 ## New Features
 
@@ -38,6 +39,7 @@
 - Extract `IUserService`/`UserService` — consolidate user registration, authentication, and profile management into a dedicated service, eliminating duplicated logic between `AuthController` and `ChatService`
 - IRC gateway now checks ban status during authentication (previously skipped)
 - EchoHubSpace directory updates — server now only sends user count when it actually changes instead of every 30 seconds
+- `ChatHub.JoinChannel` now returns `JoinChannelResult` instead of `List<MessageDto>` to allow for better error handling
 
 ## Distribution
 

src/EchoHub.Client/Services/EchoHubConnection.cs

@@ -136,8 +136,10 @@ public sealed class EchoHubConnection : IAsyncDisposable
 
     public async Task<List<MessageDto>> JoinChannelAsync(string channelName)
     {
-        var messages = await _connection.InvokeAsync<List<MessageDto>>("JoinChannel", channelName);
-        return DecryptMessages(messages);
+        var result = await _connection.InvokeAsync<JoinChannelResult>("JoinChannel", channelName);
+        if (!result.Success)
+            throw new InvalidOperationException(result.Error ?? "Failed to join channel.");
+        return DecryptMessages(result.History);
     }
 
     public async Task LeaveChannelAsync(string channelName)

src/EchoHub.Core/DTOs/ChatDtos.cs

@@ -39,6 +39,8 @@ public record UpdateTopicRequest(string? Topic);
 
 public record SendUrlRequest(string Url);
 
+public record JoinChannelResult(bool Success, List<MessageDto> History, string? Error = null);
+
 public record EmbedDto(
     string? SiteName,
     string? Title,

src/EchoHub.Server/Hubs/ChatHub.cs

@@ -56,7 +56,7 @@ public class ChatHub : Hub<IEchoHubClient>
         }
     }
 
-    public async Task<List<MessageDto>> JoinChannel(string channelName)
+    public async Task<JoinChannelResult> JoinChannel(string channelName)
     {
         try
         {
@@ -64,19 +64,15 @@ public class ChatHub : Hub<IEchoHubClient>
                 Context.ConnectionId, CurrentUserId, CurrentUsername, channelName);
 
             if (error is not null)
-            {
-                await Clients.Caller.Error(error);
-                return [];
-            }
+                return new JoinChannelResult(false, [], error);
 
             await Groups.AddToGroupAsync(Context.ConnectionId, channelName.ToLowerInvariant().Trim());
-            return history;
+            return new JoinChannelResult(true, history);
         }
         catch (Exception ex)
         {
             _logger.LogError(ex, "Error joining channel '{Channel}' for {User}", channelName, CurrentUsername);
-            await Clients.Caller.Error($"Failed to join channel: {ex.Message}");
-            return [];
+            return new JoinChannelResult(false, [], $"Failed to join channel: {ex.Message}");
         }
     }