fix(manager): Add panic recovery in token manager goroutine

- Implemented panic recovery in the Start method of entraidTokenManager to prevent crashes and ensure listener is notified of errors.

Author: ndyakov

internal/utils.go

@@ -2,7 +2,7 @@ package internal
 
 // IsClosed checks if a channel is closed.
 // Returns true only if the channel is actually closed, not just if it has data available.
-// 
+//
 // WARNING: This function will consume one value from the channel if it has pending data.
 // Use with caution on channels where consuming data might cause issues.
 func IsClosed(ch <-chan struct{}) bool {
@@ -15,4 +15,4 @@ func IsClosed(ch <-chan struct{}) bool {
 		// Channel is open but has no data available
 		return false
 	}
-}
+}

manager/entraid_manager.go

@@ -148,6 +148,16 @@ func (e *entraidTokenManager) Start(listener TokenListener) (StopFunc, error) {
 	e.listener = listener
 
 	go func(listener TokenListener, closed <-chan struct{}) {
+		// Add panic recovery to prevent crashes
+		defer func() {
+			if r := recover(); r != nil {
+				// Attempt to notify listener of panic, but don't panic again if that fails
+				func() {
+					defer func() { _ = recover() }()
+					listener.OnError(fmt.Errorf("token manager goroutine panic: %v", r))
+				}()
+			}
+		}()
 		maxDelay := e.retryOptions.MaxDelay
 		initialDelay := e.retryOptions.InitialDelay
 
@@ -223,6 +233,7 @@ func (e *entraidTokenManager) stop() (err error) {
 			err = fmt.Errorf("failed to stop token manager: %s", r)
 		}
 	}()
+
 	if e.ctxCancel != nil {
 		e.ctxCancel()
 	}