websocket: send not authenticated error

server/ws/websockets.go

@@ -31,6 +31,11 @@ type UpdateMsg struct {
 	Block  model.Block `json:"block"`
 }
 
+// ErrorMsg is sent on errors
+type ErrorMsg struct {
+	Error string `json:"error"`
+}
+
 // WebsocketCommand is an incoming command from the client.
 type WebsocketCommand struct {
 	Action   string   `json:"action"`
@@ -156,6 +161,7 @@ func (ws *Server) authenticateListener(wsSession *websocketSession, token string
 func (ws *Server) addListener(wsSession *websocketSession, blockIDs []string) {
 	if !wsSession.isAuthenticated {
 		log.Printf("addListener: NOT AUTHENTICATED")
+		sendError(wsSession.client, "not authenticated")
 		return
 	}
 
@@ -191,6 +197,7 @@ func (ws *Server) removeListener(client *websocket.Conn) {
 func (ws *Server) removeListenerFromBlocks(wsSession *websocketSession, blockIDs []string) {
 	if !wsSession.isAuthenticated {
 		log.Printf("removeListenerFromBlocks: NOT AUTHENTICATED")
+		sendError(wsSession.client, "not authenticated")
 		return
 	}
 
@@ -217,6 +224,18 @@ func (ws *Server) removeListenerFromBlocks(wsSession *websocketSession, blockIDs
 	ws.mu.Unlock()
 }
 
+func sendError(conn *websocket.Conn, message string) {
+	errorMsg := ErrorMsg{
+		Error: message,
+	}
+
+	err := conn.WriteJSON(errorMsg)
+	if err != nil {
+		log.Printf("sendError error: %v", err)
+		conn.Close()
+	}
+}
+
 // getListeners returns the listeners to a blockID's changes.
 func (ws *Server) getListeners(blockID string) []*websocket.Conn {
 	ws.mu.Lock()

webapp/src/octoListener.ts

@@ -11,9 +11,9 @@ type WSCommand = {
 
 // These are messages from the server
 type WSMessage = {
-    action: string
-    blockId: string
-    block: IBlock
+    action?: string
+    block?: IBlock
+    error?: string
 }
 
 type OnChangeHandler = (blocks: IBlock[]) => void
@@ -92,10 +92,15 @@ class OctoListener {
 
             try {
                 const message = JSON.parse(e.data) as WSMessage
+                if (message.error) {
+                    Utils.logError(`Listener websocket error: ${message.error}`)
+                    return
+                }
+
                 switch (message.action) {
                 case 'UPDATE_BLOCK':
                     Utils.log(`OctoListener update block: ${message.block?.id}`)
-                    this.queueUpdateNotification(message.block)
+                    this.queueUpdateNotification(message.block!)
                     break
                 default:
                     Utils.logError(`Unexpected action: ${message.action}`)