add common errors filtering for responses

protocol/chainlib/common.go

@@ -16,6 +16,7 @@ import (
 	"github.com/lavanet/lava/utils"
 	pairingtypes "github.com/lavanet/lava/x/pairing/types"
 	spectypes "github.com/lavanet/lava/x/spec/types"
+	"golang.org/x/exp/slices"
 	"google.golang.org/grpc/metadata"
 )
 
@@ -25,6 +26,8 @@ const (
 	debug                     = false
 )
 
+var InvalidResponses = []string{"null", "", "nil", "undefined"}
+
 type VerificationKey struct {
 	Extension string
 	Addon     string
@@ -339,3 +342,11 @@ func truncateAndPadString(s string, maxLength int) string {
 
 	return s
 }
+
+// return if response is valid or not - true
+func ValidateNilResponse(responseString string) error {
+	if !slices.Contains(InvalidResponses, responseString) {
+		return fmt.Errorf("Response returned an empty value: %s", responseString)
+	}
+	return nil
+}

protocol/chainlib/jsonRPC.go

@@ -653,6 +653,14 @@ func (cp *JrpcChainProxy) SendNodeMsg(ctx context.Context, ch chan interface{},
 		if err != nil {
 			return nil, "", nil, utils.LavaFormatError("jsonRPC error", err, utils.Attribute{Key: "GUID", Value: ctx})
 		}
+		// validate result is valid
+		if replyMessage.Error == nil {
+			responseIsNilValidationError := ValidateNilResponse(string(replyMessage.Result))
+			if responseIsNilValidationError != nil {
+				return nil, "", nil, responseIsNilValidationError
+			}
+		}
+
 		replyMsg = *replyMessage
 		err := cp.ValidateRequestAndResponseIds(nodeMessage.ID, replyMessage.ID)
 		if err != nil {

protocol/chainlib/tendermintRPC.go

@@ -753,7 +753,14 @@ func (cp *tendermintRpcChainProxy) SendRPC(ctx context.Context, nodeMessage *rpc
 		if err != nil {
 			return nil, "", nil, utils.LavaFormatError("tendermingRPC error", err)
 		}
-
+		// if we didn't get a node error.
+		if replyMessage.Error == nil {
+			// validate result is valid
+			responseIsNilValidationError := ValidateNilResponse(string(replyMessage.Result))
+			if responseIsNilValidationError != nil {
+				return nil, "", nil, responseIsNilValidationError
+			}
+		}
 		replyMsg = replyMessage
 
 		err := cp.ValidateRequestAndResponseIds(nodeMessage.ID, rpcMessage.ID)