rpc: support returning nil pointer big.Ints (null)

rpc/json.go

@@ -320,9 +320,6 @@ func parsePositionalArguments(rawArgs json.RawMessage, types []reflect.Type) ([]
 
 // CreateResponse will create a JSON-RPC success response with the given id and reply as result.
 func (c *jsonCodec) CreateResponse(id interface{}, reply interface{}) interface{} {
-	if isHexNum(reflect.TypeOf(reply)) {
-		return &jsonSuccessResponse{Version: jsonrpcVersion, Id: id, Result: fmt.Sprintf(`%#x`, reply)}
-	}
 	return &jsonSuccessResponse{Version: jsonrpcVersion, Id: id, Result: reply}
 }
 
@@ -340,11 +337,6 @@ func (c *jsonCodec) CreateErrorResponseWithInfo(id interface{}, err Error, info
 
 // CreateNotification will create a JSON-RPC notification with the given subscription id and event as params.
 func (c *jsonCodec) CreateNotification(subid, namespace string, event interface{}) interface{} {
-	if isHexNum(reflect.TypeOf(event)) {
-		return &jsonNotification{Version: jsonrpcVersion, Method: namespace + notificationMethodSuffix,
-			Params: jsonSubscription{Subscription: subid, Result: fmt.Sprintf(`%#x`, event)}}
-	}
-
 	return &jsonNotification{Version: jsonrpcVersion, Method: namespace + notificationMethodSuffix,
 		Params: jsonSubscription{Subscription: subid, Result: event}}
 }

rpc/server.go

@@ -313,7 +313,6 @@ func (s *Server) handle(ctx context.Context, codec ServerCodec, req *serverReque
 	if len(reply) == 0 {
 		return codec.CreateResponse(req.id, nil), nil
 	}
-
 	if req.callb.errPos >= 0 { // test if method returned an error
 		if !reply[req.callb.errPos].IsNil() {
 			e := reply[req.callb.errPos].Interface().(error)

rpc/utils.go

@@ -22,7 +22,6 @@ import (
 	crand "crypto/rand"
 	"encoding/binary"
 	"encoding/hex"
-	"math/big"
 	"math/rand"
 	"reflect"
 	"strings"
@@ -105,20 +104,6 @@ func formatName(name string) string {
 	return string(ret)
 }
 
-var bigIntType = reflect.TypeOf((*big.Int)(nil)).Elem()
-
-// Indication if this type should be serialized in hex
-func isHexNum(t reflect.Type) bool {
-	if t == nil {
-		return false
-	}
-	for t.Kind() == reflect.Ptr {
-		t = t.Elem()
-	}
-
-	return t == bigIntType
-}
-
 // suitableCallbacks iterates over the methods of the given type. It will determine if a method satisfies the criteria
 // for a RPC callback or a subscription callback and adds it to the collection of callbacks or subscriptions. See server
 // documentation for a summary of these criteria.