diff --git a/core/stringx/node.go b/core/stringx/node.go
index 4b6fb6e1..388e8f7b 100644
--- a/core/stringx/node.go
+++ b/core/stringx/node.go
@@ -102,6 +102,7 @@ func (n *node) find(chars []rune) []scope {
 func (n *node) longestMatch(chars []rune, start int) (used int, jump *node, matched bool) {
 	cur := n
 	var matchedNode *node
+
 	for i := start; i < len(chars); i++ {
 		child, ok := cur.children[chars[i]]
 		if ok {
@@ -113,9 +114,11 @@ func (n *node) longestMatch(chars []rune, start int) (used int, jump *node, matc
 			if matchedNode != nil {
 				return matchedNode.depth, nil, true
 			}
+
 			if n.end {
 				return start, nil, true
 			}
+
 			var jump *node
 			for cur.fail != nil {
 				jump, ok = cur.fail.children[chars[i]]
@@ -127,16 +130,20 @@ func (n *node) longestMatch(chars []rune, start int) (used int, jump *node, matc
 			if jump != nil {
 				return i + 1 - jump.depth, jump, false
 			}
+
 			return i + 1, nil, false
 		}
 	}
-	// this longest matched node
+
+	// longest matched node
 	if matchedNode != nil {
 		return matchedNode.depth, nil, true
 	}
-	// last mathed node
+
+	// last matched node
 	if n.end {
 		return start, nil, true
 	}
+
 	return len(chars), nil, false
 }
diff --git a/core/stringx/node_test.go b/core/stringx/node_test.go
index f9b8d1d0..260e21ab 100644
--- a/core/stringx/node_test.go
+++ b/core/stringx/node_test.go
@@ -6,6 +6,15 @@ import (
 	"github.com/stretchr/testify/assert"
 )
 
+func TestLongestMatchGuardedCondition(t *testing.T) {
+	n := new(node)
+	n.end = true
+	used, jump, matched := n.longestMatch([]rune(""), 0)
+	assert.Equal(t, 0, used)
+	assert.Nil(t, jump)
+	assert.True(t, matched)
+}
+
 func TestFuzzNodeCase1(t *testing.T) {
 	keywords := []string{
 		"cs8Zh",
diff --git a/core/stringx/replacer.go b/core/stringx/replacer.go
index 3edcf9c2..5447b12d 100644
--- a/core/stringx/replacer.go
+++ b/core/stringx/replacer.go
@@ -1,6 +1,8 @@
 package stringx
 
-import "strings"
+import (
+	"strings"
+)
 
 type (
 	// Replacer interface wraps the Replace method.
@@ -31,9 +33,10 @@ func NewReplacer(mapping map[string]string) Replacer {
 // Replace replaces text with given substitutes.
 func (r *replacer) Replace(text string) string {
 	var buf strings.Builder
+	var nextStart int
 	target := []rune(text)
 	cur := r.node
-	nextStart := 0
+
 	for len(target) != 0 {
 		used, jump, matched := cur.longestMatch(target, nextStart)
 		if matched {
@@ -53,5 +56,6 @@ func (r *replacer) Replace(text string) string {
 			}
 		}
 	}
+
 	return buf.String()
 }
diff --git a/core/stringx/replacer_fuzz_test.go b/core/stringx/replacer_fuzz_test.go
index 2e9facbe..da81ad9c 100644
--- a/core/stringx/replacer_fuzz_test.go
+++ b/core/stringx/replacer_fuzz_test.go
@@ -1,5 +1,4 @@
 //go:build go1.18
-// +build go1.18
 
 package stringx
 
diff --git a/core/stringx/replacer_test.go b/core/stringx/replacer_test.go
index 0d3c4015..df35448b 100644
--- a/core/stringx/replacer_test.go
+++ b/core/stringx/replacer_test.go
@@ -60,6 +60,22 @@ func TestReplacer_ReplaceLongestMatching(t *testing.T) {
 	assert.Equal(t, "东京在japan", replacer.Replace("日本的首都在日本"))
 }
 
+func TestReplacer_ReplaceLongestOverlap(t *testing.T) {
+	keywords := map[string]string{
+		"456":  "def",
+		"abcd": "1234",
+	}
+	replacer := NewReplacer(keywords)
+	assert.Equal(t, "123def7", replacer.Replace("abcd567"))
+}
+
+func TestReplacer_ReplaceLongestLonger(t *testing.T) {
+	mapping := map[string]string{
+		"c": "3",
+	}
+	assert.Equal(t, "3d", NewReplacer(mapping).Replace("cd"))
+}
+
 func TestReplacer_ReplaceJumpToFail(t *testing.T) {
 	mapping := map[string]string{
 		"bcdf": "1235",
diff --git a/zrpc/internal/rpcserver_test.go b/zrpc/internal/rpcserver_test.go
index db358b57..7cba1e3d 100644
--- a/zrpc/internal/rpcserver_test.go
+++ b/zrpc/internal/rpcserver_test.go
@@ -22,10 +22,11 @@ func TestRpcServer(t *testing.T) {
 		Breaker:    true,
 	}, WithMetrics(metrics), WithRpcHealth(true))
 	server.SetName("mock")
-	var wg sync.WaitGroup
+	var wg, wgDone sync.WaitGroup
 	var grpcServer *grpc.Server
 	var lock sync.Mutex
 	wg.Add(1)
+	wgDone.Add(1)
 	go func() {
 		err := server.Start(func(server *grpc.Server) {
 			lock.Lock()
@@ -35,6 +36,7 @@ func TestRpcServer(t *testing.T) {
 			wg.Done()
 		})
 		assert.Nil(t, err)
+		wgDone.Done()
 	}()
 
 	wg.Wait()
@@ -43,6 +45,9 @@ func TestRpcServer(t *testing.T) {
 	lock.Lock()
 	grpcServer.GracefulStop()
 	lock.Unlock()
+
+	proc.WrapUp()
+	wgDone.Wait()
 }
 
 func TestRpcServer_WithBadAddress(t *testing.T) {
@@ -58,6 +63,8 @@ func TestRpcServer_WithBadAddress(t *testing.T) {
 		mock.RegisterDepositServiceServer(server, new(mock.DepositServer))
 	})
 	assert.NotNil(t, err)
+
+	proc.WrapUp()
 }
 
 func TestRpcServer_buildUnaryInterceptor(t *testing.T) {