SubscribeSync should return error on permissions violation

[chadglaser4682]

Observed behavior

I am writing error handling logic. When I introduce in issue with the nkey I Get an error
nats: Permissions Violation for Subscription to "my..my." on connection [267]
But I can't handle the error from SubscribeSync (or Subscribe, I've tried both)

subscriptions[name], err = nc.SubscribeSync(prefix)
	if err != nil {
		errString := fmt.Sprintf("Message bus error: Subscription failed: subject=%s, prefix=%s, error=%v", "subject", prefix, err)
		return errString, "Not Connected"
	}
	time.Sleep(100 * time.Millisecond) ----> Added so I can catch the errorin nc.LastError(), otherwise the error is never caught. 
	lastError := nc.LastError()
	if lastError != nil {
		errString := fmt.Sprintf("Message bus error: %s", lastError.Error())
		return errString, "Not Connected"
	}

Expected behavior

Expected behavior would be the error being returned here.

subscriptions[name], err = nc.SubscribeSync(prefix)
if err != nil {
errString := fmt.Sprintf("Message bus error: Subscription failed: subject=%s, prefix=%s, error=%v", "subject", prefix, err)
return errString, "Not Connected"
}

Error
nats: Permissions Violation for Subscription to "agent.c4b976da-5cbf-4628-b46d-5d794c929b07.agent.c4b976da-5cbf-4628-b46d-5d794c929b07" on connection [267]
Should be returned and handled.

Server and client version

Golang code I am writing is
github.com/nats-io/nats.go v1.31.0

I think this is what the server side is getting, but I don't have access to the nats-server to run the nats-server --version command.

go install github.com/nats-io/nats-server/v2@latest 

Host environment

Client is running in
Linux 6.2.0-1019-azure x86_64

go version go1.21.7 linux/amd64

Steps to reproduce

When everything works there is no issue at all.
But when the myID is changed to something it isn't suppose to be, there is an error that if the time.sleep isn't introduced, does not get caught. The error should be returned by the call to nc.SubscribeSync(prefix). lastError can't catch the error unless the sleep is introduced. After the time.sleep the error comes up
nats: Permissions Violation for Subscription to "my..my." on connection [295]

func checkNatsConnection(config *config)(string, string)
natsConnector := msgbus.NatsConnection{}
var subscriptions = make(map[string]*nats.Subscription)
mySubject := "my." + config.myID
name := "my." + config.myID

nc, err := natsConnector.Connect(
	config.NatsConfig.EndpointUri,
	nats.UserJWTAndSeed(config.NatsConfig.Jwt, config.NatsConfig.PrivNkey),
)
if err != nil {
	errString := fmt.Sprintf("Message bus error: connection failed: %v", err)
	return errString, "Not Connected"
}
defer nc.Close()

prefix := mySubject + "." + name
subscriptions[name], err = nc.SubscribeSync(prefix)
if err != nil {
	errString := fmt.Sprintf("Message bus error: Subscription failed: subject=%s, prefix=%s, error=%v", "subject", prefix, err)
	return errString, "Not Connected"
}

time.Sleep(100 * time.Millisecond)
lastError := nc.LastError()
if lastError != nil {
	errString := fmt.Sprintf("Message bus error: %s", lastError.Error())
	return errString, "Not Connected"
}

subscriptions[name].Drain()

return "None", "Connected"

}

[piotrpio]

Hey @chadglaser4682, thanks for reporting the issue. I agree that handling subscription errors on nc isn't ideal, especially since you have to introduce delays to catch it. We are working of a way to localize the errors to be coupled with the subscription, I'll let you know here when I have something.