Method getNextMsgErr

nats.go:5526–5533

This is called when the sync channel has been closed. The error returned will be either connection or subscription closed depending on what caused NextMsg() to fail.

()

// The error returned will be either connection or subscription
// closed depending on what caused NextMsg() to fail.
func (s *Subscription) getNextMsgErr() error {
	s.mu.Lock()
	defer s.mu.Unlock()
	if s.connClosed {
		return ErrConnectionClosed
	}
	return ErrBadSubscription
}

// processNextMsgDelivered takes a message and applies the needed
// accounting to the stats from the subscription, returning an