fix: remove unutilized 'msg' from handleRequestNext() (#734)

Signed-off-by: Ales Verbic <verbotenj@blinklabs.io>

protocol/chainsync/server.go

@@ -110,7 +110,7 @@ func (s *Server) messageHandler(msg protocol.Message) error {
 	var err error
 	switch msg.Type() {
 	case MessageTypeRequestNext:
-		err = s.handleRequestNext(msg)
+		err = s.handleRequestNext()
 	case MessageTypeFindIntersect:
 		err = s.handleFindIntersect(msg)
 	case MessageTypeDone:
@@ -125,7 +125,7 @@ func (s *Server) messageHandler(msg protocol.Message) error {
 	return err
 }
 
-func (s *Server) handleRequestNext(msg protocol.Message) error {
+func (s *Server) handleRequestNext() error {
 	if s.config == nil || s.config.RequestNextFunc == nil {
 		return fmt.Errorf(
 			"received chain-sync RequestNext message but no callback function is defined",

protocol/chainsync/server_test.go

@@ -0,0 +1,54 @@
+// Copyright 2024 Blink Labs Software
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package chainsync
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestHandleRequestNext_Callback(t *testing.T) {
+	called := false
+	server := &Server{
+		config: &Config{
+			RequestNextFunc: func(ctx CallbackContext) error {
+				called = true
+				return nil
+			},
+		},
+		callbackContext: CallbackContext{},
+	}
+
+	err := server.handleRequestNext()
+
+	assert.NoError(t, err, "expected no error")
+	assert.True(t, called, "expected RequestNextFunc to be called")
+}
+
+func TestHandleRequestNext_NilCallback(t *testing.T) {
+	server := &Server{
+		config: &Config{
+			RequestNextFunc: nil,
+		},
+		callbackContext: CallbackContext{},
+	}
+
+	err := server.handleRequestNext()
+	expectedError := "received chain-sync RequestNext message but no callback function is defined"
+
+	assert.Error(t, err, "expected an error due to nil callback")
+	assert.EqualError(t, err, expectedError)
+}