update Readme and add unit tests for rpc transport

Makefile

@@ -7,7 +7,7 @@ clean:
 	@go clean
 	rm --force "xx.out"
 test:
-	@go test
+	@go test ./...
 check:
 	@go fmt ./
 	@go vet ./
@@ -29,4 +29,4 @@ help:
 	@echo "make cover - Checks the test coverage."
 	@echo "make run - Runs the program directly."
 	@echo "make lint - Performs code linting."
-	@echo "make docker - Builds a Docker image."
+	@echo "make docker - Builds a Docker image."

README.md

@@ -38,26 +38,35 @@ type ElectConfig struct {
 
 Create an Elect instance:
 ```go
-e, err := goelect.NewElect(&goelect.ElectConfig{
-		ElectTimeout:      200,
-		HeartBeatInterval: 150,
-		ConnectTimeout:    10,
-		Peers:             peerNodes,
-		// state transition callbacks
-		CallBacks: &goelect.StateCallBacks{
-			EnterLeader:    enterLeader,
-			LeaveLeader:    leaveLeader,
-			EnterFollower:  enterFollower,
-			LeaveFollower:  leaveFollower,
-			EnterCandidate: enterCandidate,
-			LeaveCandidate: leaveCandidate,
-		},
-		// self node
-		Node: goelect.Node{
-			Address: *nodeAddress,
-			ID:      *nodeAddress,
-		},
-	}, slog.Default())
+ // use the built-in RPC as the transport layer. 
+ rpcTransport, err := rpc.NewRPC(logger)
+ if err != nil {
+  return nil, err
+ }
+ e, err := goelect.NewElect(
+    rpcTransport,
+    // rpc transport config
+    &rpc.Config{},
+    &goelect.ElectConfig{
+        ElectTimeout:      200,
+        HeartBeatInterval: 150,
+        ConnectTimeout:    10,
+        Peers:             peerNodes,
+        // state transition callbacks
+        CallBacks: &goelect.StateCallBacks{
+            EnterLeader:    enterLeader,
+            LeaveLeader:    leaveLeader,
+            EnterFollower:  enterFollower,
+            LeaveFollower:  leaveFollower, 
+            EnterCandidate: enterCandidate,
+            LeaveCandidate: leaveCandidate,
+        },
+        // self node
+        Node: goelect.Node{
+            Address: *nodeAddress,
+            ID:      *nodeAddress,
+        },
+    }, logger)
 ```
 Start the Elect:
 ```go

examples/onenode/node.go

@@ -49,23 +49,12 @@ func newElect() (*goelect.Elect, error) {
 	if err != nil {
 		return nil, err
 	}
-	// rpc transport config
-	rpcTransportConfig := &rpc.Config{
-		ServerCAs:        nil,
-		ServerKey:        "",
-		ServerCert:       "",
-		ServerSkipVerify: false,
-		ClientCAs:        nil,
-		ClientCert:       "",
-		ClientKey:        "",
-		ClientSkipVerify: false,
-		ConnectTimeout:   0,
-	}
 
 	// new elect
 	e, err := goelect.NewElect(
 		rpcTransport,
-		rpcTransportConfig,
+		// rpc transport config
+		&rpc.Config{},
 		&goelect.ElectConfig{
 			ElectTimeout:      200,
 			HeartBeatInterval: 150,

pkg/transport/rpc/config_test.go

@@ -0,0 +1,119 @@
+package rpc
+
+import (
+	"errors"
+	"testing"
+)
+
+func TestConfig_Validate(t *testing.T) {
+	// Define test cases
+	tests := []struct {
+		name          string
+		config        Config
+		expectedError error
+	}{
+		{
+			name: "incomplete server certificate configuration",
+			config: Config{
+				ServerKey:        "key.pem",
+				ServerCert:       "",
+				ServerSkipVerify: false,
+				ServerCAs:        []string{},
+				ClientKey:        "",
+				ClientCert:       "",
+				ClientSkipVerify: false,
+				ClientCAs:        []string{},
+			},
+			expectedError: errors.New("incomplete server certificate configuration"),
+		},
+		{
+			name: "no server CAs configured",
+			config: Config{
+				ServerKey:        "cert.key",
+				ServerCert:       "cert.pem",
+				ServerSkipVerify: false,
+				ServerCAs:        []string{},
+				ClientKey:        "",
+				ClientCert:       "",
+				ClientSkipVerify: false,
+				ClientCAs:        []string{},
+			},
+			expectedError: errors.New("no server CAs configured"),
+		},
+		{
+			name: "incomplete client certificate configuration",
+			config: Config{
+				ServerKey:        "",
+				ServerCert:       "",
+				ServerSkipVerify: false,
+				ServerCAs:        []string{},
+				ClientKey:        "key.pem",
+				ClientCert:       "",
+				ClientSkipVerify: false,
+				ClientCAs:        []string{},
+			},
+			expectedError: errors.New("incomplete client certificate configuration"),
+		},
+		{
+			name: "no client CAs configured",
+			config: Config{
+				ServerKey:        "",
+				ServerCert:       "",
+				ServerSkipVerify: false,
+				ServerCAs:        []string{},
+				ClientKey:        "cert.key",
+				ClientCert:       "cert.pem",
+				ClientSkipVerify: false,
+				ClientCAs:        []string{},
+			},
+			expectedError: errors.New("no client CAs configured"),
+		},
+		{
+			name: "valid configuration",
+			config: Config{
+				ServerKey:        "key.pem",
+				ServerCert:       "cert.pem",
+				ServerSkipVerify: true,
+				ServerCAs:        []string{},
+				ClientKey:        "client_key.pem",
+				ClientCert:       "client_cert.pem",
+				ClientSkipVerify: true,
+				ClientCAs:        []string{},
+			},
+			expectedError: nil,
+		},
+		{
+			name: "empty configuration",
+			config: Config{
+				ServerKey:        "",
+				ServerCert:       "",
+				ServerSkipVerify: false,
+				ServerCAs:        []string{},
+				ClientKey:        "",
+				ClientCert:       "",
+				ClientSkipVerify: false,
+				ClientCAs:        []string{},
+			},
+			expectedError: nil,
+		},
+	}
+
+	// Run test cases
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			err := tt.config.Validate()
+
+			if tt.expectedError != nil && err == nil {
+				t.Errorf("expected error %v, but got nil", tt.expectedError)
+			}
+
+			if tt.expectedError == nil && err != nil {
+				t.Errorf("expected no error, but got %v", err)
+			}
+
+			if tt.expectedError != nil && err != nil && tt.expectedError.Error() != err.Error() {
+				t.Errorf("expected error %v, but got %v", tt.expectedError, err)
+			}
+		})
+	}
+}