.github/workflows/lint.yaml

@@ -29,7 +29,7 @@ jobs:
         with:
           # This field is required.  Dont set the patch version to always use
           # the latest patch version.
-          version: v1.50.0
+          version: v1.52.0
   notify:
     needs:
       - golangci

internal/netutil/netutil.go

@@ -74,7 +74,7 @@ func SortNetIPAddrs(addrs []netip.Addr, preferIPv6 bool) {
 		}
 
 		aIs4, bIs4 := addrA.Is4(), addrB.Is4()
-		if aIs4 != bIs4 {
+		if aIs4 == bIs4 {
 			return addrA.Compare(addrB)
 		}
 

internal/netutil/netutil_test.go

+package netutil_test
+
+import (
+	"net/netip"
+	"testing"
+
+	"github.com/AdguardTeam/dnsproxy/internal/netutil"
+	"github.com/stretchr/testify/assert"
+	"golang.org/x/exp/slices"
+)
+
+func TestSortNetIPAddrs(t *testing.T) {
+	var (
+		aIPv4    = netip.MustParseAddr("1.2.3.4")
+		bIPv4    = netip.MustParseAddr("4.3.2.1")
+		aIPv6    = netip.MustParseAddr("2a00::1234")
+		bIPv6    = netip.MustParseAddr("2a00::4321")
+		badIP, _ = netip.ParseAddr("bad")
+	)
+
+	testCases := []struct {
+		name       string
+		addrs      []netip.Addr
+		want       []netip.Addr
+		preferIPv6 bool
+	}{{
+		name:       "v4_preferred",
+		addrs:      []netip.Addr{aIPv6, bIPv6, badIP, aIPv4, bIPv4},
+		want:       []netip.Addr{aIPv4, bIPv4, aIPv6, bIPv6, badIP},
+		preferIPv6: false,
+	}, {
+		name:       "v6_preferred",
+		addrs:      []netip.Addr{aIPv4, bIPv4, badIP, aIPv6, bIPv6},
+		want:       []netip.Addr{aIPv6, bIPv6, aIPv4, bIPv4, badIP},
+		preferIPv6: true,
+	}, {
+		name:       "shuffled_v4_preferred",
+		addrs:      []netip.Addr{badIP, aIPv4, bIPv6, aIPv6, bIPv4},
+		want:       []netip.Addr{aIPv4, bIPv4, aIPv6, bIPv6, badIP},
+		preferIPv6: false,
+	}, {
+		name:       "shuffled_v6_preferred",
+		addrs:      []netip.Addr{badIP, aIPv4, bIPv6, aIPv6, bIPv4},
+		want:       []netip.Addr{aIPv6, bIPv6, aIPv4, bIPv4, badIP},
+		preferIPv6: true,
+	}, {
+		name:       "empty",
+		addrs:      []netip.Addr{},
+		want:       []netip.Addr{},
+		preferIPv6: false,
+	}, {
+		name:       "single",
+		addrs:      []netip.Addr{aIPv4},
+		want:       []netip.Addr{aIPv4},
+		preferIPv6: false,
+	}, {
+		name:       "start_with_ipv4",
+		addrs:      []netip.Addr{aIPv4, aIPv6, bIPv4, bIPv6},
+		want:       []netip.Addr{aIPv6, bIPv6, aIPv4, bIPv4},
+		preferIPv6: true,
+	}, {
+		name:       "start_with_ipv6",
+		addrs:      []netip.Addr{aIPv6, aIPv4, bIPv6, bIPv4},
+		want:       []netip.Addr{aIPv6, bIPv6, aIPv4, bIPv4},
+		preferIPv6: true,
+	}}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			ips := slices.Clone(tc.addrs)
+			netutil.SortNetIPAddrs(ips, tc.preferIPv6)
+			assert.Equal(t, tc.want, ips)
+		})
+	}
+}