pkg/config: use modern Go stdlib for sorting and string operations (#5210)

- slices.SortedFunc + maps.Values + cmp.Compare instead of manual
  map-to-slice collection + sort.Slice (source/aggregator.go)
- strings.CutSuffix instead of HasSuffix+TrimSuffix, and deduplicate
  error handling in BandwidthQuantity.UnmarshalString (types/types.go)

pkg/config/source/aggregator.go

@@ -15,9 +15,11 @@
 package source
 
 import (
+	"cmp"
 	"errors"
 	"fmt"
-	"sort"
+	"maps"
+	"slices"
 	"sync"
 
 	v1 "github.com/fatedier/frp/pkg/config/v1"
@@ -97,21 +99,11 @@ func (a *Aggregator) mapsToSortedSlices(
 	proxyMap map[string]v1.ProxyConfigurer,
 	visitorMap map[string]v1.VisitorConfigurer,
 ) ([]v1.ProxyConfigurer, []v1.VisitorConfigurer) {
-	proxies := make([]v1.ProxyConfigurer, 0, len(proxyMap))
-	for _, p := range proxyMap {
-		proxies = append(proxies, p)
-	}
-	sort.Slice(proxies, func(i, j int) bool {
-		return proxies[i].GetBaseConfig().Name < proxies[j].GetBaseConfig().Name
+	proxies := slices.SortedFunc(maps.Values(proxyMap), func(x, y v1.ProxyConfigurer) int {
+		return cmp.Compare(x.GetBaseConfig().Name, y.GetBaseConfig().Name)
 	})
-
-	visitors := make([]v1.VisitorConfigurer, 0, len(visitorMap))
-	for _, v := range visitorMap {
-		visitors = append(visitors, v)
-	}
-	sort.Slice(visitors, func(i, j int) bool {
-		return visitors[i].GetBaseConfig().Name < visitors[j].GetBaseConfig().Name
+	visitors := slices.SortedFunc(maps.Values(visitorMap), func(x, y v1.VisitorConfigurer) int {
+		return cmp.Compare(x.GetBaseConfig().Name, y.GetBaseConfig().Name)
 	})
-
 	return proxies, visitors
 }

pkg/config/source/aggregator_test.go

@@ -196,6 +196,27 @@ func TestAggregator_VisitorMerge(t *testing.T) {
 	require.Len(visitors, 2)
 }
 
+func TestAggregator_Load_ReturnsSortedByName(t *testing.T) {
+	require := require.New(t)
+
+	agg := newTestAggregator(t, nil)
+	err := agg.ConfigSource().ReplaceAll(
+		[]v1.ProxyConfigurer{mockProxy("charlie"), mockProxy("alice"), mockProxy("bob")},
+		[]v1.VisitorConfigurer{mockVisitor("zulu"), mockVisitor("alpha")},
+	)
+	require.NoError(err)
+
+	proxies, visitors, err := agg.Load()
+	require.NoError(err)
+	require.Len(proxies, 3)
+	require.Equal("alice", proxies[0].GetBaseConfig().Name)
+	require.Equal("bob", proxies[1].GetBaseConfig().Name)
+	require.Equal("charlie", proxies[2].GetBaseConfig().Name)
+	require.Len(visitors, 2)
+	require.Equal("alpha", visitors[0].GetBaseConfig().Name)
+	require.Equal("zulu", visitors[1].GetBaseConfig().Name)
+}
+
 func TestAggregator_Load_ReturnsDefensiveCopies(t *testing.T) {
 	require := require.New(t)
 

pkg/config/types/types.go

@@ -70,24 +70,18 @@ func (q *BandwidthQuantity) UnmarshalString(s string) error {
 		f    float64
 		err  error
 	)
-	switch {
-	case strings.HasSuffix(s, "MB"):
+	if fstr, ok := strings.CutSuffix(s, "MB"); ok {
 		base = MB
-		fstr := strings.TrimSuffix(s, "MB")
 		f, err = strconv.ParseFloat(fstr, 64)
-		if err != nil {
-			return err
-		}
-	case strings.HasSuffix(s, "KB"):
+	} else if fstr, ok := strings.CutSuffix(s, "KB"); ok {
 		base = KB
-		fstr := strings.TrimSuffix(s, "KB")
 		f, err = strconv.ParseFloat(fstr, 64)
-		if err != nil {
-			return err
-		}
-	default:
+	} else {
 		return errors.New("unit not support")
 	}
+	if err != nil {
+		return err
+	}
 
 	q.s = s
 	q.i = int64(f * float64(base))

pkg/config/types/types_test.go

@@ -39,6 +39,31 @@ func TestBandwidthQuantity(t *testing.T) {
 	require.Equal(`{"b":"1KB","int":5}`, string(buf))
 }
 
+func TestBandwidthQuantity_MB(t *testing.T) {
+	require := require.New(t)
+
+	var w Wrap
+	err := json.Unmarshal([]byte(`{"b":"2MB","int":1}`), &w)
+	require.NoError(err)
+	require.EqualValues(2*MB, w.B.Bytes())
+
+	buf, err := json.Marshal(&w)
+	require.NoError(err)
+	require.Equal(`{"b":"2MB","int":1}`, string(buf))
+}
+
+func TestBandwidthQuantity_InvalidUnit(t *testing.T) {
+	var w Wrap
+	err := json.Unmarshal([]byte(`{"b":"1GB","int":1}`), &w)
+	require.Error(t, err)
+}
+
+func TestBandwidthQuantity_InvalidNumber(t *testing.T) {
+	var w Wrap
+	err := json.Unmarshal([]byte(`{"b":"abcKB","int":1}`), &w)
+	require.Error(t, err)
+}
+
 func TestPortsRangeSlice2String(t *testing.T) {
 	require := require.New(t)