feat: making it work even better...i abandon writing tests first...😅

.editorconfig

@@ -65,7 +65,7 @@ dotnet_style_prefer_auto_properties = true:suggestion
 dotnet_style_prefer_collection_expression = when_types_loosely_match:suggestion
 dotnet_style_prefer_compound_assignment = true:suggestion
 dotnet_style_prefer_conditional_expression_over_assignment = true:suggestion
-dotnet_style_prefer_conditional_expression_over_return = true:suggestion
+dotnet_style_prefer_conditional_expression_over_return = false:silent
 dotnet_style_prefer_foreach_explicit_cast_in_source = when_strongly_typed:suggestion
 dotnet_style_prefer_inferred_anonymous_type_member_names = true:suggestion
 dotnet_style_prefer_inferred_tuple_names = true:suggestion

src/StevesBot.Worker/Discord/DiscordCloseCodes.cs

@@ -0,0 +1,21 @@
+namespace StevesBot.Worker.Discord;
+
+internal static class DiscordCloseCodes
+{
+  private const int AuthenticationFailed = 4004;
+  private const int InvalidShard = 4010;
+  private const int ShardingRequired = 4011;
+  private const int InvalidAPIVersion = 4012;
+  private const int InvalidIntents = 4013;
+  private const int DisallowedIntents = 4014;
+
+  public static bool IsReconnectable(int? closeCode)
+  {
+    return closeCode is not AuthenticationFailed
+      and not InvalidShard
+      and not ShardingRequired
+      and not InvalidAPIVersion
+      and not InvalidIntents
+      and not DisallowedIntents;
+  }
+}

src/StevesBot.Worker/Discord/DiscordGatewayClient.cs

@@ -4,6 +4,11 @@ namespace StevesBot.Worker.Discord;
 
 internal sealed class DiscordGatewayClient : IDiscordGatewayClient
 {
+  private const string VersionKey = "v";
+  private const string VersionValue = "10";
+  private const string EncodingKey = "encoding";
+  private const string EncodingValue = "json";
+
   private readonly DiscordClientOptions _options;
   private readonly IWebSocketFactory _webSocketFactory;
   private readonly ILogger<DiscordGatewayClient> _logger;
@@ -23,6 +28,7 @@ internal sealed class DiscordGatewayClient : IDiscordGatewayClient
   private string _gatewayUrl = string.Empty;
   private IWebSocket? _webSocket;
   private int? _lastSequence;
+  private int? _lastDispatchSequence;
   private int _heartbeatInterval;
   private DateTimeOffset _timeLastHeartbeatSent = DateTimeOffset.MinValue;
   private DateTimeOffset _timeLastHeartbeatAcknowledged = DateTimeOffset.MinValue;
@@ -94,11 +100,6 @@ internal sealed class DiscordGatewayClient : IDiscordGatewayClient
 
         while (_linkedReceiveMessageCts?.IsCancellationRequested is false)
         {
-          // websocket message might be larger than the
-          // size of the buffer so we need to loop until
-          // we receive the end of the message and
-          // write the data we receive on each iteration
-          // to the memory stream
           using var memoryStream = new MemoryStream();
           WebSocketReceiveResult result;
 
@@ -108,16 +109,23 @@ internal sealed class DiscordGatewayClient : IDiscordGatewayClient
 
             if (result.MessageType is WebSocketMessageType.Close)
             {
-              // TODO: Handle all possible close codes
-              // reconnect accordingly to documentation
-              var canResume = result.CloseStatus is not WebSocketCloseStatus.NormalClosure or WebSocketCloseStatus.EndpointUnavailable
-                && string.IsNullOrWhiteSpace(_resumeGatewayUrl) is false
-                && string.IsNullOrWhiteSpace(_sessionId) is false;
+              if (DiscordCloseCodes.IsReconnectable((int?)result.CloseStatus) is false)
+              {
+                _logger.LogCritical("Received close status indicating we should not attempt reconnection: {CloseStatus}", result.CloseStatus);
+                await DisconnectAsync(cancellationToken);
+                return;
+              }
+
+              var canResume = IsResumableCloseCode(result.CloseStatus);
+              var closeStatus = canResume ? WebSocketCloseStatus.Empty : WebSocketCloseStatus.NormalClosure;
 
               await SetCanResumeAsync(canResume, _linkedReceiveMessageCts.Token);
-              await CloseIfOpenAsync(result.CloseStatus ?? WebSocketCloseStatus.NormalClosure, result.CloseStatusDescription, _linkedReceiveMessageCts.Token);
-              _logger.LogInformation("Reconnecting because of close message: {CloseStatus} - {CloseStatusDescription}", result.CloseStatus, result.CloseStatusDescription);
+              await CloseIfOpenAsync(closeStatus, result.CloseStatusDescription, _linkedReceiveMessageCts.Token);
+
+              _logger.LogWarning("Reconnecting because of close message: {CloseStatus} - {CloseStatusDescription}", result.CloseStatus, result.CloseStatusDescription);
+
               await ReconnectAsync(cancellationToken);
+
               return;
             }
 
@@ -165,7 +173,9 @@ internal sealed class DiscordGatewayClient : IDiscordGatewayClient
         );
 
         await SetCanResumeAsync(false, newReceiveLinkedCts.Token);
-        _logger.LogInformation("Reconnecting because of error in receive message task");
+
+        _logger.LogWarning("Reconnecting because of error in receive message task");
+
         await ReconnectAsync(cancellationToken);
       }
     }, newReceiveLinkedCts.Token);
@@ -182,16 +192,77 @@ internal sealed class DiscordGatewayClient : IDiscordGatewayClient
         await SetHeartbeatIntervalAsync(he.Data.HeartbeatInterval, cancellationToken);
         await StartHeartbeatAsync(cancellationToken);
         await IdentifyAsync(cancellationToken);
-        _logger.LogInformation("Hello event received. Heartbeat interval: {Interval}", he.Data.HeartbeatInterval);
+        _logger.LogInformation("Hello event received");
         break;
       case HeartbeatAckDiscordEvent:
         await SetHeartbeatAcknowledgedAsync(_timeProvider.GetUtcNow(), cancellationToken);
         _logger.LogInformation("Heartbeat acknowledged");
         break;
-      case ReadyDiscordEvent re:
-        await SetSessionIdAsync(re.Data.SessionId, cancellationToken);
-        await SetResumeGatewayUrlAsync(re.Data.ResumeGatewayUrl, cancellationToken);
-        _logger.LogInformation("Ready event received");
+      case HeartbeatDiscordEvent:
+        _logger.LogInformation("Heartbeat request received");
+        await SendHeartbeatAsync(cancellationToken);
+        break;
+      case DispatchDiscordEvent de:
+        await SetDispatchSequenceAsync(e.Sequence, cancellationToken);
+
+        switch (de)
+        {
+          case ReadyDiscordEvent re:
+            await SetSessionIdAsync(re.Data.SessionId, cancellationToken);
+            await SetResumeGatewayUrlAsync(re.Data.ResumeGatewayUrl, cancellationToken);
+            _logger.LogInformation("Ready event received");
+            break;
+          default:
+            _logger.LogInformation("Received dispatch event: {Event}", de.Type ?? "Unknown");
+            break;
+        }
+        break;
+      case ReconnectDiscordEvent:
+        _logger.LogInformation("Reconnect event received");
+
+        _logger.LogWarning("Closing connection without invalidating session.");
+
+        await SetCanResumeAsync(true, cancellationToken);
+
+        await CloseIfOpenAsync(
+          WebSocketCloseStatus.Empty,
+          "Reconnect event received",
+          cancellationToken
+        );
+
+        _logger.LogWarning("Reconnecting because of reconnect event");
+
+        await ReconnectAsync(cancellationToken);
+        break;
+      case InvalidSessionDiscordEvent ise:
+        _logger.LogInformation("Invalid session event received");
+
+        if (ise.Data)
+        {
+          _logger.LogWarning("Session is resumable. Closing connection without invalidating session.");
+
+          await SetCanResumeAsync(true, cancellationToken);
+
+          await CloseIfOpenAsync(
+            WebSocketCloseStatus.Empty,
+            "Invalid session event received",
+            cancellationToken
+          );
+        }
+        else
+        {
+          _logger.LogWarning("Session is not resumable. Closing connection and invalidating session.");
+
+          await SetCanResumeAsync(false, cancellationToken);
+
+          await CloseIfOpenAsync(
+            WebSocketCloseStatus.NormalClosure,
+            "Invalid session event received",
+            cancellationToken
+          );
+        }
+
+        await ReconnectAsync(cancellationToken);
         break;
       default:
         _logger.LogInformation("Received event: {Event}", e.GetType().Name);
@@ -237,7 +308,9 @@ internal sealed class DiscordGatewayClient : IDiscordGatewayClient
             }
 
             _logger.LogWarning("Heartbeat not acknowledged. Reconnecting.");
+
             await ReconnectAsync(cancellationToken);
+
             break;
           }
 
@@ -263,7 +336,8 @@ internal sealed class DiscordGatewayClient : IDiscordGatewayClient
             newLinkedCts.Token
           );
 
-          _logger.LogInformation("Reconnecting because of error in heartbeat task");
+          _logger.LogWarning("Reconnecting because of error in heartbeat task");
+
           await ReconnectAsync(cancellationToken);
         }
       }
@@ -296,7 +370,7 @@ internal sealed class DiscordGatewayClient : IDiscordGatewayClient
 
     using (await _lock.LockAsync(cancellationToken))
     {
-      if (_lastSequence is null)
+      if (_lastDispatchSequence is null)
       {
         throw new DiscordGatewayClientException("Cannot resume without a sequence number.");
       }
@@ -304,7 +378,7 @@ internal sealed class DiscordGatewayClient : IDiscordGatewayClient
       resume = new ResumeDiscordEvent(
         _options.AppToken,
         _sessionId,
-        _lastSequence.Value
+        _lastDispatchSequence.Value
       );
     }
 
@@ -360,6 +434,21 @@ internal sealed class DiscordGatewayClient : IDiscordGatewayClient
     }
   }
 
+  private bool IsResumableCloseCode(WebSocketCloseStatus? closeStatus)
+  {
+    if (string.IsNullOrWhiteSpace(_resumeGatewayUrl) || string.IsNullOrWhiteSpace(_sessionId))
+    {
+      return false;
+    }
+
+    if (closeStatus is WebSocketCloseStatus.NormalClosure or WebSocketCloseStatus.EndpointUnavailable)
+    {
+      return false;
+    }
+
+    return true;
+  }
+
   private bool IsWebSocketOpen()
   {
     return _webSocket?.State is WebSocketState.Open;
@@ -486,22 +575,19 @@ internal sealed class DiscordGatewayClient : IDiscordGatewayClient
     return result;
   }
 
-  private async Task ConnectWithGatewayUrlAsync(CancellationToken cancellationToken)
+  private Task ConnectWithGatewayUrlAsync(CancellationToken cancellationToken)
   {
-    if (_webSocket is null)
-    {
-      throw new DiscordGatewayClientException("WebSocket is not set. Cannot connect.");
-    }
-
-    if (_webSocket.State is WebSocketState.Open)
-    {
-      throw new DiscordGatewayClientException("WebSocket is already open. Cannot connect.");
-    }
-
-    await _webSocket.ConnectAsync(new Uri(_gatewayUrl), cancellationToken);
+    var uri = BuildUri(_gatewayUrl);
+    return ConnectWithUriAsync(uri, cancellationToken);
   }
 
-  private async Task ConnectWithResumeUrlAsync(CancellationToken cancellationToken)
+  private Task ConnectWithResumeUrlAsync(CancellationToken cancellationToken)
+  {
+    var uri = BuildUri(_resumeGatewayUrl);
+    return ConnectWithUriAsync(uri, cancellationToken);
+  }
+
+  private async Task ConnectWithUriAsync(Uri uri, CancellationToken cancellationToken)
   {
     if (_webSocket is null)
     {
@@ -513,7 +599,15 @@ internal sealed class DiscordGatewayClient : IDiscordGatewayClient
       throw new DiscordGatewayClientException("WebSocket is already open. Cannot connect.");
     }
 
-    await _webSocket.ConnectAsync(new Uri(_resumeGatewayUrl), cancellationToken);
+    await _webSocket.ConnectAsync(uri, cancellationToken);
+  }
+
+  private static Uri BuildUri(string url)
+  {
+    return new UriBuilder(url)
+    {
+      Query = $"{VersionKey}={VersionValue}&{EncodingKey}={EncodingValue}"
+    }.Uri;
   }
 
   private async Task SetGatewayUrlAsync(string url, CancellationToken cancellationToken)
@@ -522,6 +616,12 @@ internal sealed class DiscordGatewayClient : IDiscordGatewayClient
     _gatewayUrl = url;
   }
 
+  private async Task SetDispatchSequenceAsync(int? sequence, CancellationToken cancellationToken)
+  {
+    using var _ = await _lock.LockAsync(cancellationToken);
+    _lastDispatchSequence = sequence;
+  }
+
   private async Task SetSequenceAsync(int? sequence, CancellationToken cancellationToken)
   {
     using var _ = await _lock.LockAsync(cancellationToken);

src/StevesBot.Worker/Discord/Events/DiscordEventConverter.cs

@@ -14,6 +14,9 @@ internal sealed class DiscordEventConverter : JsonConverter<DiscordEvent>
     return op switch
     {
       DiscordOpCodes.Dispatch => DeserializeDispatchEvent(root, options, modifiedOptions),
+      DiscordOpCodes.Heartbeat => JsonSerializer.Deserialize<HeartbeatDiscordEvent>(root.GetRawText(), options),
+      DiscordOpCodes.Reconnect => JsonSerializer.Deserialize<ReconnectDiscordEvent>(root.GetRawText(), options),
+      DiscordOpCodes.InvalidSession => JsonSerializer.Deserialize<InvalidSessionDiscordEvent>(root.GetRawText(), options),
       DiscordOpCodes.Hello => JsonSerializer.Deserialize<HelloDiscordEvent>(root.GetRawText(), options),
       DiscordOpCodes.HeartbeatAck => JsonSerializer.Deserialize<HeartbeatAckDiscordEvent>(root.GetRawText(), options),
       _ => JsonSerializer.Deserialize<DiscordEvent>(root.GetRawText(), modifiedOptions),
@@ -26,14 +29,14 @@ internal sealed class DiscordEventConverter : JsonConverter<DiscordEvent>
     JsonSerializer.Serialize(writer, value, value.GetType(), modifiedOptions);
   }
 
-  private static DiscordEvent? DeserializeDispatchEvent(JsonElement root, JsonSerializerOptions options, JsonSerializerOptions modifiedOptions)
+  private static DispatchDiscordEvent? DeserializeDispatchEvent(JsonElement root, JsonSerializerOptions options, JsonSerializerOptions modifiedOptions)
   {
     var type = root.GetProperty("t").GetString();
 
     return type switch
     {
       DiscordEventTypes.Ready => JsonSerializer.Deserialize<ReadyDiscordEvent>(root.GetRawText(), options),
-      _ => JsonSerializer.Deserialize<DiscordEvent>(root.GetRawText(), modifiedOptions),
+      _ => JsonSerializer.Deserialize<DispatchDiscordEvent>(root.GetRawText(), modifiedOptions),
     };
   }
 

src/StevesBot.Worker/Discord/Events/DiscordOpCodes.cs

@@ -6,6 +6,8 @@ internal static class DiscordOpCodes
   public const int Heartbeat = 1;
   public const int Identify = 2;
   public const int Resume = 6;
+  public const int Reconnect = 7;
+  public const int InvalidSession = 9;
   public const int HeartbeatAck = 11;
   public const int Hello = 10;
 }

src/StevesBot.Worker/Discord/Events/DispatchDiscordEvent.cs

@@ -0,0 +1,5 @@
+namespace StevesBot.Worker.Discord.Events;
+
+internal record DispatchDiscordEvent : DiscordEvent
+{
+}

src/StevesBot.Worker/Discord/Events/InvalidSessionDiscordEvent.cs

@@ -0,0 +1,7 @@
+namespace StevesBot.Worker.Discord.Events;
+
+internal sealed record InvalidSessionDiscordEvent : DiscordEvent
+{
+  [JsonPropertyName("d")]
+  public new bool Data { get; init; }
+}

src/StevesBot.Worker/Discord/Events/ReadyDiscordEvent.cs

@@ -1,6 +1,6 @@
 namespace StevesBot.Worker.Discord.Events;
 
-internal record ReadyDiscordEvent : DiscordEvent
+internal record ReadyDiscordEvent : DispatchDiscordEvent
 {
   [JsonPropertyName("d")]
   public new ReadyData Data { get; init; } = new ReadyData();
@@ -16,4 +16,4 @@ internal record ReadyData
 
   [JsonPropertyName("resume_gateway_url")]
   public string ResumeGatewayUrl { get; init; } = string.Empty;
-}
+}

src/StevesBot.Worker/Discord/Events/ReconnectDiscordEvent.cs

@@ -0,0 +1,5 @@
+namespace StevesBot.Worker.Discord;
+
+internal sealed record ReconnectDiscordEvent : DiscordEvent
+{
+}