Chore: support MarshalYAML to some config filed (#581)

dns/util.go

@@ -11,7 +11,6 @@ import (
 	"github.com/Dreamacro/clash/log"
 
 	D "github.com/miekg/dns"
-	yaml "gopkg.in/yaml.v2"
 )
 
 var (
@@ -46,8 +45,8 @@ func (e *EnhancedMode) UnmarshalYAML(unmarshal func(interface{}) error) error {
 }
 
 // MarshalYAML serialize EnhancedMode with yaml
-func (e EnhancedMode) MarshalYAML() ([]byte, error) {
-	return yaml.Marshal(e.String())
+func (e EnhancedMode) MarshalYAML() (interface{}, error) {
+	return e.String(), nil
 }
 
 // UnmarshalJSON unserialize EnhancedMode with json

log/level.go

@@ -55,6 +55,11 @@ func (l LogLevel) MarshalJSON() ([]byte, error) {
 	return json.Marshal(l.String())
 }
 
+// MarshalYAML serialize LogLevel with yaml
+func (l LogLevel) MarshalYAML() (interface{}, error) {
+	return l.String(), nil
+}
+
 func (l LogLevel) String() string {
 	switch l {
 	case INFO:

tunnel/mode.go

@@ -51,6 +51,11 @@ func (m TunnelMode) MarshalJSON() ([]byte, error) {
 	return json.Marshal(m.String())
 }
 
+// MarshalYAML serialize TunnelMode with yaml
+func (m TunnelMode) MarshalYAML() (interface{}, error) {
+	return m.String(), nil
+}
+
 func (m TunnelMode) String() string {
 	switch m {
 	case Global: