Add resolver for outbound dialer

option/config.go

@@ -2,17 +2,19 @@ package option
 
 import (
 	"bytes"
+	"strings"
 
 	"github.com/sagernet/sing/common"
+	E "github.com/sagernet/sing/common/exceptions"
 
 	"github.com/goccy/go-json"
 )
 
 type _Options struct {
 	Log       *LogOption    `json:"log,omitempty"`
+	DNS       *DNSOptions   `json:"dns,omitempty"`
 	Inbounds  []Inbound     `json:"inbounds,omitempty"`
 	Outbounds []Outbound    `json:"outbounds,omitempty"`
-	DNS       *DNSOptions   `json:"dns,omitempty"`
 	Route     *RouteOptions `json:"route,omitempty"`
 }
 
@@ -21,11 +23,22 @@ type Options _Options
 func (o *Options) UnmarshalJSON(content []byte) error {
 	decoder := json.NewDecoder(bytes.NewReader(content))
 	decoder.DisallowUnknownFields()
-	return decoder.Decode((*_Options)(o))
+	err := decoder.Decode((*_Options)(o))
+	if err == nil {
+		return nil
+	}
+	if syntaxError, isSyntaxError := err.(*json.SyntaxError); isSyntaxError {
+		prefix := string(content[:syntaxError.Offset])
+		row := strings.Count(prefix, "\n") + 1
+		column := len(prefix) - strings.LastIndex(prefix, "\n") - 1
+		return E.Extend(syntaxError, "row ", row, ", column ", column)
+	}
+	return err
 }
 
 func (o Options) Equals(other Options) bool {
 	return common.ComparablePtrEquals(o.Log, other.Log) &&
+		common.PtrEquals(o.DNS, other.DNS) &&
 		common.SliceEquals(o.Inbounds, other.Inbounds) &&
 		common.ComparableSliceEquals(o.Outbounds, other.Outbounds) &&
 		common.PtrEquals(o.Route, other.Route)