refactor: improve connection management and simplify handleMessage function

Author: topi314

gateway/gateway.go

@@ -239,19 +239,22 @@ func (g *gatewayImpl) open(ctx context.Context) error {
 	g.lastHeartbeatSent = time.Now().UTC()
 	conn, rs, err := g.config.Dialer.DialContext(ctx, gatewayURL, nil)
 	if err != nil {
-		body := ""
-		if rs != nil && rs.Body != nil {
+		var body []byte
+		if rs != nil {
 			defer func() {
 				_ = rs.Body.Close()
 			}()
-			rawBody, bErr := io.ReadAll(rs.Body)
-			if bErr != nil {
-				g.config.Logger.ErrorContext(ctx, "error while reading response body", slog.Any("err", bErr))
+			body, err = io.ReadAll(rs.Body)
+			if err != nil {
+				g.config.Logger.ErrorContext(ctx, "error while reading response body", slog.Any("err", err))
 			}
-			body = string(rawBody)
 		}
 
-		g.config.Logger.ErrorContext(ctx, "error connecting to the gateway", slog.Any("err", err), slog.String("url", gatewayURL), slog.String("body", body))
+		g.config.Logger.ErrorContext(ctx, "error connecting to the gateway",
+			slog.Any("err", err),
+			slog.String("url", gatewayURL),
+			slog.String("body", string(body)),
+		)
 		g.connMu.Unlock()
 		return err
 	}
@@ -303,7 +306,7 @@ func (g *gatewayImpl) Close(ctx context.Context) {
 
 func (g *gatewayImpl) CloseWithCode(ctx context.Context, code int, message string) {
 	if g.heartbeatCancel != nil {
-		g.config.Logger.DebugContext(ctx, "closing heartbeat goroutines...")
+		g.config.Logger.DebugContext(ctx, "closing heartbeat goroutine")
 		g.heartbeatCancel()
 	}
 
@@ -382,8 +385,10 @@ func (g *gatewayImpl) Presence() *MessageDataPresenceUpdate {
 }
 
 func (g *gatewayImpl) doReconnect(ctx context.Context) error {
-	try := 0
-	backoffIncrement := 0
+	var (
+		try              int
+		backoffIncrement int
+	)
 
 	for {
 		// Exponentially backoff up to a limit of 10s

gateway/gateway_messages.go

@@ -65,6 +65,7 @@ func (e *Message) UnmarshalJSON(data []byte) error {
 		messageData = d
 
 	case OpcodeReconnect:
+		messageData = MessageDataReconnect{}
 
 	case OpcodeRequestGuildMembers:
 		var d MessageDataRequestGuildMembers
@@ -82,6 +83,7 @@ func (e *Message) UnmarshalJSON(data []byte) error {
 		messageData = d
 
 	case OpcodeHeartbeatACK:
+		messageData = MessageDataHeartbeatACK{}
 
 	case OpcodeRequestSoundboardSounds:
 		var d MessageDataRequestSoundboardSounds
@@ -658,6 +660,10 @@ type MessageDataResume struct {
 
 func (MessageDataResume) messageData() {}
 
+type MessageDataReconnect struct{}
+
+func (MessageDataReconnect) messageData() {}
+
 // MessageDataRequestGuildMembers is used for fetching all the members of a guild_events. It is recommended you have a strict
 // member caching policy when using this.
 type MessageDataRequestGuildMembers struct {
@@ -681,6 +687,10 @@ type MessageDataHello struct {
 
 func (MessageDataHello) messageData() {}
 
+type MessageDataHeartbeatACK struct{}
+
+func (MessageDataHeartbeatACK) messageData() {}
+
 type MessageDataRequestSoundboardSounds struct {
 	GuildIDs []snowflake.ID `json:"guild_ids"`
 }

voice/conn.go

@@ -194,7 +194,7 @@ func (c *connImpl) HandleVoiceServerUpdate(update botgateway.EventVoiceServerUpd
 	}()
 }
 
-func (c *connImpl) handleMessage(gateway Gateway, op Opcode, data GatewayMessageData) {
+func (c *connImpl) handleMessage(gateway Gateway, op Opcode, sequenceNumber int, data GatewayMessageData) {
 	switch d := data.(type) {
 	case GatewayMessageDataReady:
 		ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
@@ -238,7 +238,7 @@ func (c *connImpl) handleMessage(gateway Gateway, op Opcode, data GatewayMessage
 		}
 	}
 	if c.config.EventHandlerFunc != nil {
-		c.config.EventHandlerFunc(c.gateway, op, data)
+		c.config.EventHandlerFunc(gateway, op, sequenceNumber, data)
 	}
 }