allow groups to be created without initial outbounds

Author: garmr-ulfr

protocol/group/mutableselector.go

@@ -54,17 +54,13 @@ type MutableSelector struct {
 }
 
 func NewMutableSelector(ctx context.Context, router A.Router, logger log.ContextLogger, tag string, options option.MutableSelectorOutboundOptions) (A.Outbound, error) {
-	tags := options.Outbounds
-	if len(tags) == 0 {
-		return nil, errors.New("missing tags")
-	}
 	selector := &MutableSelector{
 		Adapter:        outbound.NewAdapter(constant.TypeMutableSelector, tag, nil, nil),
 		ctx:            ctx,
 		outboundMgr:    service.FromContext[A.OutboundManager](ctx),
 		connMgr:        service.FromContext[A.ConnectionManager](ctx),
 		logger:         logger,
-		tags:           tags,
+		tags:           options.Outbounds,
 		outbounds:      make(map[string]A.Outbound),
 		interruptGroup: interrupt.NewGroup(),
 	}
@@ -75,6 +71,10 @@ func (s *MutableSelector) Start() error {
 	s.mu.Lock()
 	defer s.mu.Unlock()
 
+	if len(s.tags) == 0 {
+		return nil
+	}
+
 	for _, tag := range s.tags {
 		outbound, found := s.outboundMgr.Outbound(tag)
 		if !found {

protocol/group/mutableurltest.go

@@ -52,9 +52,6 @@ type MutableURLTest struct {
 }
 
 func NewMutableURLTest(ctx context.Context, _ A.Router, logger log.ContextLogger, tag string, options option.MutableURLTestOutboundOptions) (A.Outbound, error) {
-	if len(options.Outbounds) == 0 {
-		return nil, errors.New("missing tags")
-	}
 	interval := time.Duration(options.Interval)
 	if interval == 0 {
 		interval = C.DefaultURLTestInterval
@@ -241,6 +238,13 @@ type urlTestGroup struct {
 }
 
 func (g *urlTestGroup) Start() error {
+	g.access.Lock()
+	defer g.access.Unlock()
+
+	if len(g.tags) == 0 {
+		return nil
+	}
+
 	for _, tag := range g.tags {
 		outbound, found := g.outboundMgr.Outbound(tag)
 		if !found {
@@ -349,7 +353,7 @@ func (g *urlTestGroup) Remove(tags []string) (n int, err error) {
 func (g *urlTestGroup) keepAlive() {
 	g.access.Lock()
 	defer g.access.Unlock()
-	if !g.started {
+	if !g.started || len(g.tags) == 0 {
 		return
 	}
 	if !g.running.CompareAndSwap(false, true) {