How to throw error correctly in actor method?

[raymondsze]

I have an actor within following method

func (t *TestActor) Invoke(ctx context.Context, req string) (string, error) {
	return "", errors.New("Custom Message")
}

And I invoke the actor like this

	ctx, _ = context.WithTimeout(ctx, time.Second*15)
	rsp, err := myActor.Invoke(ctx, "laurence")
	if err != nil {
		panic(err)
	}
	fmt.Println("get invoke result = ", rsp)

It should always go panic(err), but the error shown is always "panic: error invoking binding testActorType/ActorImplID5121f5e3-bb26-4362-a199-e20ec9ebd5d5: rpc error: code = Internal desc = error invoke actor method: rpc error: code = Internal desc = error invoke actor method: error from actor service: "

Please advise..., also how to customize the grpc error code? now its always "Internal".

[qazwsxedckll]

// InvokeMethod to invoke local function by @actorID, @methodName and @request request param.
func (m *DefaultActorManagerContext) InvokeMethod(ctx context.Context, actorID, methodName string, request []byte) ([]byte, actorErr.ActorErr) {
	if m.factory == nil {
		return nil, actorErr.ErrActorFactoryNotSet
	}

	actorContainer, aerr := m.getAndCreateActorContainerIfNotExist(ctx, actorID)
	if aerr != actorErr.Success {
		return nil, aerr
	}
	returnValue, aerr := actorContainer.Invoke(ctx, methodName, request)
	if aerr != actorErr.Success {
		return nil, aerr
	}
	if len(returnValue) == 1 {
		return nil, actorErr.Success
	}

	var (
		retErr interface{}
		replyv reflect.Value
	)

	if len(returnValue) == 2 {
		replyv = returnValue[0]
		retErr = returnValue[1].Interface()
	}

	if retErr != nil {
		return nil, actorErr.ErrActorInvokeFailed
	}
	rspData, err := m.serializer.Marshal(replyv.Interface())
	if err != nil {
		return nil, actorErr.ErrActorMethodSerializeFailed
	}
	if err := actorContainer.GetActor().SaveState(ctx); err != nil {
		return nil, actorErr.ErrSaveStateFailed
	}
	return rspData, actorErr.Success
}

While investigating your problem, I also find that the response such as error is ignored when len(returnValue) == 1 and SaveState(ctx) is not invoked.

Any response from the contributer?

@LaurenceLiZhixin

Update:

Your problem comes from

	if retErr != nil {
		return nil, actorErr.ErrActorInvokeFailed
	}

the business error get thrown here also.

	// register actor method invoke handler
	fInvoke := func(w http.ResponseWriter, r *http.Request) {
		actorType := chi.URLParam(r, "actorType")
		actorID := chi.URLParam(r, "actorId")
		methodName := chi.URLParam(r, "methodName")
		reqData, _ := io.ReadAll(r.Body)
		rspData, err := runtime.GetActorRuntimeInstanceContext().InvokeActorMethod(r.Context(), actorType, actorID, methodName, reqData)
		if err == actorErr.ErrActorTypeNotFound {
			w.WriteHeader(http.StatusNotFound)
			return
		}
		if err != actorErr.Success {
			w.WriteHeader(http.StatusInternalServerError)    // <--------here
			return
		}
		w.WriteHeader(http.StatusOK)
		_, _ = w.Write(rspData)
	}
	s.mux.Put("/actors/{actorType}/{actorId}/method/{methodName}", fInvoke)

when actorErr is not Success, the body is empty.

	if resp.Status().GetCode() != http.StatusOK {
		respData, _ := resp.RawDataFull()
		return nil, fmt.Errorf("error from actor service: %s", string(respData))
	}

In dapr runtime, the message is printed here.