Remove null outbounds in group references

template/filter/filter_null_group_reference.go

@@ -0,0 +1,33 @@
+package filter
+
+import (
+	M "github.com/sagernet/serenity/common/metadata"
+	C "github.com/sagernet/sing-box/constant"
+	"github.com/sagernet/sing-box/option"
+	"github.com/sagernet/sing/common"
+)
+
+func init() {
+	filters = append(filters, filterNullGroupReference)
+}
+
+func filterNullGroupReference(metadata M.Metadata, options *option.Options) {
+	outboundTags := common.Map(options.Outbounds, func(it option.Outbound) string {
+		return it.Tag
+	})
+	for i, outbound := range options.Outbounds {
+		switch outbound.Type {
+		case C.TypeSelector:
+			outbound.SelectorOptions.Outbounds = common.Filter(outbound.SelectorOptions.Outbounds, func(outbound string) bool {
+				return common.Contains(outboundTags, outbound)
+			})
+		case C.TypeURLTest:
+			outbound.URLTestOptions.Outbounds = common.Filter(outbound.URLTestOptions.Outbounds, func(outbound string) bool {
+				return common.Contains(outboundTags, outbound)
+			})
+		default:
+			continue
+		}
+		options.Outbounds[i] = outbound
+	}
+}