diff --git a/app/dns/dnscommon_test.go b/app/dns/dnscommon_test.go
index 62a35012..d6f43c65 100644
--- a/app/dns/dnscommon_test.go
+++ b/app/dns/dnscommon_test.go
@@ -16,10 +16,6 @@ import (
 )
 
 func Test_parseResponse(t *testing.T) {
-	type args struct {
-		payload []byte
-	}
-
 	var p [][]byte
 
 	ans := new(dns.Msg)
diff --git a/app/dns/server.go b/app/dns/server.go
index 2d89f3aa..6598008f 100644
--- a/app/dns/server.go
+++ b/app/dns/server.go
@@ -308,7 +308,7 @@ func (s *Server) lookupIPInternal(domain string, option IPOption) ([]net.IP, err
 	}
 
 	// skip domain without any dot
-	if strings.Index(domain, ".") == -1 {
+	if !strings.Contains(domain, ".") {
 		return nil, newError("invalid domain name").AtWarning()
 	}
 
diff --git a/app/router/condition.go b/app/router/condition.go
index 4a80471f..209a60a3 100644
--- a/app/router/condition.go
+++ b/app/router/condition.go
@@ -294,10 +294,7 @@ func NewAttributeMatcher(code string) (*AttributeMatcher, error) {
 		return nil, newError("attr rule").Base(err)
 	}
 	p, err := starlark.FileProgram(starFile, func(name string) bool {
-		if name == "attrs" {
-			return true
-		}
-		return false
+		return name == "attrs"
 	})
 	if err != nil {
 		return nil, err
diff --git a/infra/conf/vmess.go b/infra/conf/vmess.go
index b9531fde..838fa263 100644
--- a/infra/conf/vmess.go
+++ b/infra/conf/vmess.go
@@ -126,8 +126,6 @@ type VMessOutboundConfig struct {
 	Receivers []*VMessOutboundTarget `json:"vnext"`
 }
 
-var bUser = "a06fe789-5ab1-480b-8124-ae4599801ff3"
-
 // Build implements Buildable
 func (c *VMessOutboundConfig) Build() (proto.Message, error) {
 	config := new(outbound.Config)
diff --git a/proxy/shadowsocks/protocol.go b/proxy/shadowsocks/protocol.go
index 8c9d6935..7dd432bc 100644
--- a/proxy/shadowsocks/protocol.go
+++ b/proxy/shadowsocks/protocol.go
@@ -50,7 +50,6 @@ func ReadTCPSession(user *protocol.MemoryUser, reader io.Reader) (*protocol.Requ
 		return nil, nil, newError("failed to initialize decoding stream").Base(err).AtError()
 	}
 	br := &buf.BufferedReader{Reader: r}
-	reader = nil
 
 	authenticator := NewAuthenticator(HeaderKeyGenerator(account.Key, iv))
 	request := &protocol.RequestHeader{
diff --git a/proxy/vmess/validator.go b/proxy/vmess/validator.go
index bf64d98a..a7664db4 100644
--- a/proxy/vmess/validator.go
+++ b/proxy/vmess/validator.go
@@ -159,8 +159,7 @@ func (v *TimedUserValidator) Get(userHash []byte) (*protocol.MemoryUser, protoco
 	copy(fixedSizeHash[:], userHash)
 	pair, found := v.userHash[fixedSizeHash]
 	if found {
-		var user protocol.MemoryUser
-		user = pair.user.user
+		user := pair.user.user
 		if atomic.LoadUint32(pair.taintedFuse) == 0 {
 			return &user, protocol.Timestamp(pair.timeInc) + v.baseTime, true, nil
 		}
diff --git a/testing/servers/http/http.go b/testing/servers/http/http.go
index 6bada232..379da590 100644
--- a/testing/servers/http/http.go
+++ b/testing/servers/http/http.go
@@ -9,7 +9,6 @@ import (
 type Server struct {
 	Port        net.Port
 	PathHandler map[string]http.HandlerFunc
-	accepting   bool
 	server      *http.Server
 }