Add multiple configuration support

common/badjsonmerge/merge.go

@@ -0,0 +1,80 @@
+package badjsonmerge
+
+import (
+	"encoding/json"
+	"reflect"
+
+	"github.com/sagernet/sing-box/common/badjson"
+	"github.com/sagernet/sing-box/option"
+	E "github.com/sagernet/sing/common/exceptions"
+)
+
+func MergeOptions(source option.Options, destination option.Options) (option.Options, error) {
+	rawSource, err := json.Marshal(source)
+	if err != nil {
+		return option.Options{}, E.Cause(err, "marshal source")
+	}
+	rawDestination, err := json.Marshal(destination)
+	if err != nil {
+		return option.Options{}, E.Cause(err, "marshal destination")
+	}
+	rawMerged, err := MergeJSON(rawSource, rawDestination)
+	if err != nil {
+		return option.Options{}, E.Cause(err, "merge options")
+	}
+	var merged option.Options
+	err = json.Unmarshal(rawMerged, &merged)
+	if err != nil {
+		return option.Options{}, E.Cause(err, "unmarshal merged options")
+	}
+	return merged, nil
+}
+
+func MergeJSON(rawSource json.RawMessage, rawDestination json.RawMessage) (json.RawMessage, error) {
+	source, err := badjson.Decode(rawSource)
+	if err != nil {
+		return nil, E.Cause(err, "decode source")
+	}
+	destination, err := badjson.Decode(rawDestination)
+	if err != nil {
+		return nil, E.Cause(err, "decode destination")
+	}
+	merged, err := mergeJSON(source, destination)
+	if err != nil {
+		return nil, err
+	}
+	return json.Marshal(merged)
+}
+
+func mergeJSON(anySource any, anyDestination any) (any, error) {
+	switch destination := anyDestination.(type) {
+	case badjson.JSONArray:
+		switch source := anySource.(type) {
+		case badjson.JSONArray:
+			destination = append(destination, source...)
+		default:
+			destination = append(destination, source)
+		}
+		return destination, nil
+	case *badjson.JSONObject:
+		switch source := anySource.(type) {
+		case *badjson.JSONObject:
+			for _, entry := range source.Entries() {
+				oldValue, loaded := destination.Get(entry.Key)
+				if loaded {
+					var err error
+					entry.Value, err = mergeJSON(entry.Value, oldValue)
+					if err != nil {
+						return nil, E.Cause(err, "merge object item ", entry.Key)
+					}
+				}
+				destination.Put(entry.Key, entry.Value)
+			}
+		default:
+			return nil, E.New("cannot merge json object into ", reflect.TypeOf(destination))
+		}
+		return destination, nil
+	default:
+		return destination, nil
+	}
+}

common/badjsonmerge/merge_test.go

@@ -0,0 +1,59 @@
+package badjsonmerge
+
+import (
+	"testing"
+
+	C "github.com/sagernet/sing-box/constant"
+	"github.com/sagernet/sing-box/option"
+	N "github.com/sagernet/sing/common/network"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestMergeJSON(t *testing.T) {
+	t.Parallel()
+	options := option.Options{
+		Log: &option.LogOptions{
+			Level: "info",
+		},
+		Route: &option.RouteOptions{
+			Rules: []option.Rule{
+				{
+					Type: C.RuleTypeDefault,
+					DefaultOptions: option.DefaultRule{
+						Network:  N.NetworkTCP,
+						Outbound: "direct",
+					},
+				},
+			},
+		},
+	}
+	anotherOptions := option.Options{
+		Outbounds: []option.Outbound{
+			{
+				Type: C.TypeDirect,
+				Tag:  "direct",
+			},
+		},
+	}
+	thirdOptions := option.Options{
+		Route: &option.RouteOptions{
+			Rules: []option.Rule{
+				{
+					Type: C.RuleTypeDefault,
+					DefaultOptions: option.DefaultRule{
+						Network:  N.NetworkUDP,
+						Outbound: "direct",
+					},
+				},
+			},
+		},
+	}
+	mergeOptions, err := MergeOptions(options, anotherOptions)
+	require.NoError(t, err)
+	mergeOptions, err = MergeOptions(thirdOptions, mergeOptions)
+	require.NoError(t, err)
+	require.Equal(t, "info", mergeOptions.Log.Level)
+	require.Equal(t, 2, len(mergeOptions.Route.Rules))
+	require.Equal(t, C.TypeDirect, mergeOptions.Outbounds[0].Type)
+}