core: upgrade Go requirement to 1.26.0 (#8466)

* core: upgrade Go requirement to 1.26.0

As golang 1.27 has been released, this PR
- Bump Go version requirement to 1.26.0
- Update Go build version to 1.27.0

This is also for solving the issue encountered in 8092 of k8s update

Signed-off-by: Yong Tang <yong.tang.github@outlook.com>

* Bump golang ci

Signed-off-by: Yong Tang <yong.tang.github@outlook.com>

* Fix

Signed-off-by: Yong Tang <yong.tang.github@outlook.com>

* Fix

Signed-off-by: Yong Tang <yong.tang.github@outlook.com>

* Fix

Signed-off-by: Yong Tang <yong.tang.github@outlook.com>

* Migrate faillint to forbidigo, as failint has not bee updated for more than a year

Signed-off-by: Yong Tang <yong.tang.github@outlook.com>

---------

Signed-off-by: Yong Tang <yong.tang.github@outlook.com>

plugin/dns64/dns64_test.go

@@ -507,7 +507,7 @@ func TestDNS64(t *testing.T) {
 			}
 			actual := rec.Msg
 			if actual.Rcode != rc {
-				t.Fatalf("ServeDNS should return real result code %q != %q", actual.Rcode, rc)
+				t.Fatalf("ServeDNS should return real result code %d != %d", actual.Rcode, rc)
 			}
 
 			if !reflect.DeepEqual(actual, tc.resp) {

plugin/file/secondary_test.go

@@ -92,7 +92,7 @@ func TestShouldTransfer(t *testing.T) {
 		t.Fatalf("Unable to run shouldTransfer: %v", err)
 	}
 	if !should {
-		t.Fatalf("ShouldTransfer should return true for serial: %q", soa.serial-1)
+		t.Fatalf("ShouldTransfer should return true for serial: %d", soa.serial-1)
 	}
 	// Serial equal
 	z.SOA = test.SOA(fmt.Sprintf("%s IN SOA bla. bla. %d 0 0 0 0 ", testZone, soa.serial))

plugin/grpc_server/setup_test.go

@@ -32,14 +32,14 @@ func TestSetup(t *testing.T) {
 				max_streams 100
 			}`,
 			shouldErr:          false,
-			expectedMaxStreams: intPtr(100),
+			expectedMaxStreams: new(100),
 		},
 		{
 			input: `grpc_server {
 				max_connections 200
 			}`,
 			shouldErr:              false,
-			expectedMaxConnections: intPtr(200),
+			expectedMaxConnections: new(200),
 		},
 		{
 			input: `grpc_server {
@@ -47,8 +47,8 @@ func TestSetup(t *testing.T) {
 				max_connections 100
 			}`,
 			shouldErr:              false,
-			expectedMaxStreams:     intPtr(50),
-			expectedMaxConnections: intPtr(100),
+			expectedMaxStreams:     new(50),
+			expectedMaxConnections: new(100),
 		},
 		// Zero values (unbounded)
 		{
@@ -56,14 +56,14 @@ func TestSetup(t *testing.T) {
 				max_streams 0
 			}`,
 			shouldErr:          false,
-			expectedMaxStreams: intPtr(0),
+			expectedMaxStreams: new(0),
 		},
 		{
 			input: `grpc_server {
 				max_connections 0
 			}`,
 			shouldErr:              false,
-			expectedMaxConnections: intPtr(0),
+			expectedMaxConnections: new(0),
 		},
 		// Error cases
 		{
@@ -139,9 +139,7 @@ func TestSetup(t *testing.T) {
 	}
 }
 
-func intPtr(v int) *int {
-	return &v
-}
+//go:fix inline
 
 func assertIntPtrValue(t *testing.T, testIndex int, testInput, fieldName string, actual, expected *int) {
 	t.Helper()

plugin/https/setup_test.go

@@ -48,14 +48,14 @@ func TestSetup(t *testing.T) {
 				max_connections 200
 			}`,
 			shouldErr:              false,
-			expectedMaxConnections: intPtr(200),
+			expectedMaxConnections: new(200),
 		},
 		{
 			input: `https {
 				max_streams 100
 			}`,
 			shouldErr:          false,
-			expectedMaxStreams: intPtr(100),
+			expectedMaxStreams: new(100),
 		},
 		{
 			input: `https {
@@ -63,8 +63,8 @@ func TestSetup(t *testing.T) {
 				max_streams 100
 			}`,
 			shouldErr:              false,
-			expectedMaxConnections: intPtr(200),
-			expectedMaxStreams:     intPtr(100),
+			expectedMaxConnections: new(200),
+			expectedMaxStreams:     new(100),
 		},
 		// Zero values (unbounded)
 		{
@@ -72,7 +72,7 @@ func TestSetup(t *testing.T) {
 				max_connections 0
 			}`,
 			shouldErr:              false,
-			expectedMaxConnections: intPtr(0),
+			expectedMaxConnections: new(0),
 		},
 		// Error cases
 		{
@@ -123,7 +123,7 @@ func TestSetup(t *testing.T) {
 				max_streams 0
 			}`,
 			shouldErr:          false,
-			expectedMaxStreams: intPtr(0),
+			expectedMaxStreams: new(0),
 		},
 		{
 			input: `https {
@@ -199,9 +199,7 @@ func TestSetup(t *testing.T) {
 	}
 }
 
-func intPtr(v int) *int {
-	return &v
-}
+//go:fix inline
 
 func assertIntPtrValue(t *testing.T, testIndex int, testInput, fieldName string, actual, expected *int) {
 	t.Helper()

plugin/https3/setup_test.go

@@ -31,7 +31,7 @@ func TestSetup(t *testing.T) {
 				max_streams 100
 			}`,
 			shouldErr:          false,
-			expectedMaxStreams: intPtr(100),
+			expectedMaxStreams: new(100),
 		},
 		// Zero values (unbounded)
 		{
@@ -39,7 +39,7 @@ func TestSetup(t *testing.T) {
 				max_streams 0
 			}`,
 			shouldErr:          false,
-			expectedMaxStreams: intPtr(0),
+			expectedMaxStreams: new(0),
 		},
 		// Error cases
 		{
@@ -114,9 +114,7 @@ func TestSetup(t *testing.T) {
 	}
 }
 
-func intPtr(v int) *int {
-	return &v
-}
+//go:fix inline
 
 func assertIntPtrValue(t *testing.T, testIndex int, testInput, fieldName string, actual, expected *int) {
 	t.Helper()

plugin/kubernetes/controller.go

@@ -132,7 +132,7 @@ type dnsControlOpts struct {
 }
 
 // newdnsController creates a controller for CoreDNS.
-func newdnsController(ctx context.Context, kubeClient kubernetes.Interface, mcsClient mcsClientset.MulticlusterV1alpha1Interface, opts dnsControlOpts) *dnsControl {
+func newdnsController(_ context.Context, kubeClient kubernetes.Interface, mcsClient mcsClientset.MulticlusterV1alpha1Interface, opts dnsControlOpts) *dnsControl {
 	dns := dnsControl{
 		client:            kubeClient,
 		mcsClient:         mcsClient,
@@ -147,8 +147,8 @@ func newdnsController(ctx context.Context, kubeClient kubernetes.Interface, mcsC
 	dns.svcLister, dns.svcController = object.NewIndexerInformer(
 		cache.ToListWatcherWithWatchListSemantics(
 			&cache.ListWatch{
-				ListFunc:  serviceListFunc(ctx, dns.client, api.NamespaceAll, dns.selector),
-				WatchFunc: serviceWatchFunc(ctx, dns.client, api.NamespaceAll, dns.selector),
+				ListWithContextFunc:  serviceListFunc(dns.client, api.NamespaceAll, dns.selector),
+				WatchFuncWithContext: serviceWatchFunc(dns.client, api.NamespaceAll, dns.selector),
 			},
 			kubeClient,
 		),
@@ -161,8 +161,8 @@ func newdnsController(ctx context.Context, kubeClient kubernetes.Interface, mcsC
 	podLister, podController := object.NewIndexerInformer(
 		cache.ToListWatcherWithWatchListSemantics(
 			&cache.ListWatch{
-				ListFunc:  podListFunc(ctx, dns.client, api.NamespaceAll, dns.selector),
-				WatchFunc: podWatchFunc(ctx, dns.client, api.NamespaceAll, dns.selector),
+				ListWithContextFunc:  podListFunc(dns.client, api.NamespaceAll, dns.selector),
+				WatchFuncWithContext: podWatchFunc(dns.client, api.NamespaceAll, dns.selector),
 			},
 			kubeClient,
 		),
@@ -183,8 +183,8 @@ func newdnsController(ctx context.Context, kubeClient kubernetes.Interface, mcsC
 	epLister, epController := object.NewIndexerInformer(
 		cache.ToListWatcherWithWatchListSemantics(
 			&cache.ListWatch{
-				ListFunc:  endpointSliceListFunc(ctx, dns.client, api.NamespaceAll, dns.selector),
-				WatchFunc: endpointSliceWatchFunc(ctx, dns.client, api.NamespaceAll, dns.selector),
+				ListWithContextFunc:  endpointSliceListFunc(dns.client, api.NamespaceAll, dns.selector),
+				WatchFuncWithContext: endpointSliceWatchFunc(dns.client, api.NamespaceAll, dns.selector),
 			},
 			kubeClient,
 		),
@@ -201,8 +201,8 @@ func newdnsController(ctx context.Context, kubeClient kubernetes.Interface, mcsC
 	dns.nsLister, dns.nsController = object.NewIndexerInformer(
 		cache.ToListWatcherWithWatchListSemantics(
 			&cache.ListWatch{
-				ListFunc:  namespaceListFunc(ctx, dns.client, dns.namespaceSelector),
-				WatchFunc: namespaceWatchFunc(ctx, dns.client, dns.namespaceSelector),
+				ListWithContextFunc:  namespaceListFunc(dns.client, dns.namespaceSelector),
+				WatchFuncWithContext: namespaceWatchFunc(dns.client, dns.namespaceSelector),
 			},
 			kubeClient,
 		),
@@ -222,8 +222,8 @@ func newdnsController(ctx context.Context, kubeClient kubernetes.Interface, mcsC
 		dns.mcEpLister, dns.mcEpController = object.NewIndexerInformer(
 			cache.ToListWatcherWithWatchListSemantics(
 				&cache.ListWatch{
-					ListFunc:  endpointSliceListFunc(ctx, dns.client, api.NamespaceAll, mcsEpSelector),
-					WatchFunc: endpointSliceWatchFunc(ctx, dns.client, api.NamespaceAll, mcsEpSelector),
+					ListWithContextFunc:  endpointSliceListFunc(dns.client, api.NamespaceAll, mcsEpSelector),
+					WatchFuncWithContext: endpointSliceWatchFunc(dns.client, api.NamespaceAll, mcsEpSelector),
 				},
 				kubeClient,
 			),
@@ -235,8 +235,8 @@ func newdnsController(ctx context.Context, kubeClient kubernetes.Interface, mcsC
 		dns.svcImportLister, dns.svcImportController = object.NewIndexerInformer(
 			cache.ToListWatcherWithWatchListSemantics(
 				&cache.ListWatch{
-					ListFunc:  serviceImportListFunc(ctx, dns.mcsClient, api.NamespaceAll, dns.namespaceSelector),
-					WatchFunc: serviceImportWatchFunc(ctx, dns.mcsClient, api.NamespaceAll, dns.namespaceSelector),
+					ListWithContextFunc:  serviceImportListFunc(dns.mcsClient, api.NamespaceAll, dns.namespaceSelector),
+					WatchFuncWithContext: serviceImportWatchFunc(dns.mcsClient, api.NamespaceAll, dns.namespaceSelector),
 				},
 				kubeClient,
 			),
@@ -334,8 +334,8 @@ func mcEpNameNamespaceIndexFunc(obj any) ([]string, error) {
 	return []string{mcEp.Index}, nil
 }
 
-func serviceListFunc(ctx context.Context, c kubernetes.Interface, ns string, s labels.Selector) func(meta.ListOptions) (runtime.Object, error) {
-	return func(opts meta.ListOptions) (runtime.Object, error) {
+func serviceListFunc(c kubernetes.Interface, ns string, s labels.Selector) func(context.Context, meta.ListOptions) (runtime.Object, error) {
+	return func(ctx context.Context, opts meta.ListOptions) (runtime.Object, error) {
 		if s != nil {
 			opts.LabelSelector = s.String()
 		}
@@ -343,8 +343,8 @@ func serviceListFunc(ctx context.Context, c kubernetes.Interface, ns string, s l
 	}
 }
 
-func podListFunc(ctx context.Context, c kubernetes.Interface, ns string, s labels.Selector) func(meta.ListOptions) (runtime.Object, error) {
-	return func(opts meta.ListOptions) (runtime.Object, error) {
+func podListFunc(c kubernetes.Interface, ns string, s labels.Selector) func(context.Context, meta.ListOptions) (runtime.Object, error) {
+	return func(ctx context.Context, opts meta.ListOptions) (runtime.Object, error) {
 		if s != nil {
 			opts.LabelSelector = s.String()
 		}
@@ -356,8 +356,8 @@ func podListFunc(ctx context.Context, c kubernetes.Interface, ns string, s label
 	}
 }
 
-func endpointSliceListFunc(ctx context.Context, c kubernetes.Interface, ns string, s labels.Selector) func(meta.ListOptions) (runtime.Object, error) {
-	return func(opts meta.ListOptions) (runtime.Object, error) {
+func endpointSliceListFunc(c kubernetes.Interface, ns string, s labels.Selector) func(context.Context, meta.ListOptions) (runtime.Object, error) {
+	return func(ctx context.Context, opts meta.ListOptions) (runtime.Object, error) {
 		if s != nil {
 			opts.LabelSelector = s.String()
 		}
@@ -365,8 +365,8 @@ func endpointSliceListFunc(ctx context.Context, c kubernetes.Interface, ns strin
 	}
 }
 
-func namespaceListFunc(ctx context.Context, c kubernetes.Interface, s labels.Selector) func(meta.ListOptions) (runtime.Object, error) {
-	return func(opts meta.ListOptions) (runtime.Object, error) {
+func namespaceListFunc(c kubernetes.Interface, s labels.Selector) func(context.Context, meta.ListOptions) (runtime.Object, error) {
+	return func(ctx context.Context, opts meta.ListOptions) (runtime.Object, error) {
 		if s != nil {
 			opts.LabelSelector = s.String()
 		}
@@ -374,8 +374,8 @@ func namespaceListFunc(ctx context.Context, c kubernetes.Interface, s labels.Sel
 	}
 }
 
-func serviceImportListFunc(ctx context.Context, c mcsClientset.MulticlusterV1alpha1Interface, ns string, s labels.Selector) func(meta.ListOptions) (runtime.Object, error) {
-	return func(opts meta.ListOptions) (runtime.Object, error) {
+func serviceImportListFunc(c mcsClientset.MulticlusterV1alpha1Interface, ns string, s labels.Selector) func(context.Context, meta.ListOptions) (runtime.Object, error) {
+	return func(ctx context.Context, opts meta.ListOptions) (runtime.Object, error) {
 		if s != nil {
 			opts.LabelSelector = s.String()
 		}
@@ -383,8 +383,8 @@ func serviceImportListFunc(ctx context.Context, c mcsClientset.MulticlusterV1alp
 	}
 }
 
-func serviceWatchFunc(ctx context.Context, c kubernetes.Interface, ns string, s labels.Selector) func(options meta.ListOptions) (watch.Interface, error) {
-	return func(options meta.ListOptions) (watch.Interface, error) {
+func serviceWatchFunc(c kubernetes.Interface, ns string, s labels.Selector) func(context.Context, meta.ListOptions) (watch.Interface, error) {
+	return func(ctx context.Context, options meta.ListOptions) (watch.Interface, error) {
 		if s != nil {
 			options.LabelSelector = s.String()
 		}
@@ -392,8 +392,8 @@ func serviceWatchFunc(ctx context.Context, c kubernetes.Interface, ns string, s
 	}
 }
 
-func podWatchFunc(ctx context.Context, c kubernetes.Interface, ns string, s labels.Selector) func(options meta.ListOptions) (watch.Interface, error) {
-	return func(options meta.ListOptions) (watch.Interface, error) {
+func podWatchFunc(c kubernetes.Interface, ns string, s labels.Selector) func(context.Context, meta.ListOptions) (watch.Interface, error) {
+	return func(ctx context.Context, options meta.ListOptions) (watch.Interface, error) {
 		if s != nil {
 			options.LabelSelector = s.String()
 		}
@@ -405,8 +405,8 @@ func podWatchFunc(ctx context.Context, c kubernetes.Interface, ns string, s labe
 	}
 }
 
-func endpointSliceWatchFunc(ctx context.Context, c kubernetes.Interface, ns string, s labels.Selector) func(options meta.ListOptions) (watch.Interface, error) {
-	return func(options meta.ListOptions) (watch.Interface, error) {
+func endpointSliceWatchFunc(c kubernetes.Interface, ns string, s labels.Selector) func(context.Context, meta.ListOptions) (watch.Interface, error) {
+	return func(ctx context.Context, options meta.ListOptions) (watch.Interface, error) {
 		if s != nil {
 			options.LabelSelector = s.String()
 		}
@@ -414,8 +414,8 @@ func endpointSliceWatchFunc(ctx context.Context, c kubernetes.Interface, ns stri
 	}
 }
 
-func namespaceWatchFunc(ctx context.Context, c kubernetes.Interface, s labels.Selector) func(options meta.ListOptions) (watch.Interface, error) {
-	return func(options meta.ListOptions) (watch.Interface, error) {
+func namespaceWatchFunc(c kubernetes.Interface, s labels.Selector) func(context.Context, meta.ListOptions) (watch.Interface, error) {
+	return func(ctx context.Context, options meta.ListOptions) (watch.Interface, error) {
 		if s != nil {
 			options.LabelSelector = s.String()
 		}
@@ -423,8 +423,8 @@ func namespaceWatchFunc(ctx context.Context, c kubernetes.Interface, s labels.Se
 	}
 }
 
-func serviceImportWatchFunc(ctx context.Context, c mcsClientset.MulticlusterV1alpha1Interface, ns string, s labels.Selector) func(options meta.ListOptions) (watch.Interface, error) {
-	return func(options meta.ListOptions) (watch.Interface, error) {
+func serviceImportWatchFunc(c mcsClientset.MulticlusterV1alpha1Interface, ns string, s labels.Selector) func(context.Context, meta.ListOptions) (watch.Interface, error) {
+	return func(ctx context.Context, options meta.ListOptions) (watch.Interface, error) {
 		if s != nil {
 			options.LabelSelector = s.String()
 		}

plugin/kubernetes/object/deepcopy_test.go

@@ -11,7 +11,7 @@ import (
 	mcs "sigs.k8s.io/mcs-api/pkg/apis/v1alpha1"
 )
 
-func ptrTo[T any](v T) *T { return &v }
+//go:fix inline
 
 // dump renders an object for a failure message. %+v prints an aliased pointer field as
 // an address, which hides the value that actually differs, so render as JSON instead.
@@ -76,7 +76,7 @@ func deepCopyCases() []struct {
 			Ports: []api.ServicePort{{
 				Name: "http", Protocol: api.ProtocolTCP, Port: 80,
 				// A pointer field, so a slice copy alone leaves it shared.
-				AppProtocol: ptrTo("kubernetes.io/h2c"),
+				AppProtocol: new("kubernetes.io/h2c"),
 			}},
 			ExternalIPs: []string{"1.2.3.4"},
 		}},
@@ -89,7 +89,7 @@ func deepCopyCases() []struct {
 			Type:       mcs.ClusterSetIP,
 			Ports: []mcs.ServicePort{{
 				Name: "http", Protocol: api.ProtocolTCP, Port: 80,
-				AppProtocol: ptrTo("kubernetes.io/h2c"),
+				AppProtocol: new("kubernetes.io/h2c"),
 			}},
 		}},
 		{"Namespace", &Namespace{Version: "1", Name: "testns"}},

plugin/pkg/proxy/doq_test.go

@@ -176,12 +176,12 @@ func makeDoQTestTLSConfigs(t *testing.T) (*tls.Config, *tls.Config) {
 	}
 	roots.AddCert(parsed)
 	return &tls.Config{
-			Certificates: []tls.Certificate{cert},
-			NextProtos:   []string{doqALPN},
-		}, &tls.Config{
-			RootCAs:    roots,
-			ServerName: "doq.test",
-		}
+		Certificates: []tls.Certificate{cert},
+		NextProtos:   []string{doqALPN},
+	}, &tls.Config{
+		RootCAs:    roots,
+		ServerName: "doq.test",
+	}
 }
 
 func writeDoQTestResponse(stream *quic.Stream, response *dns.Msg) error {
@@ -291,8 +291,7 @@ func TestProxyDoQVerifiesServerName(t *testing.T) {
 	if err == nil {
 		t.Fatal("Connect() succeeded with the wrong TLS server name")
 	}
-	var hostnameError x509.HostnameError
-	if !errors.As(err, &hostnameError) {
+	if _, ok := errors.AsType[x509.HostnameError](err); !ok {
 		t.Fatalf("Connect() error = %T %v, want x509.HostnameError", err, err)
 	}
 }

plugin/pkg/tls/tls.go

@@ -141,10 +141,10 @@ func loadRoots(caPath string) (*x509.CertPool, error) {
 func NewHTTPSTransport(cc *tls.Config) *http.Transport {
 	tr := &http.Transport{
 		Proxy: http.ProxyFromEnvironment,
-		Dial: (&net.Dialer{
+		DialContext: (&net.Dialer{
 			Timeout:   30 * time.Second,
 			KeepAlive: 30 * time.Second,
-		}).Dial,
+		}).DialContext,
 		TLSHandshakeTimeout: 10 * time.Second,
 		TLSClientConfig:     cc,
 		MaxIdleConnsPerHost: 25,

plugin/quic/setup_test.go

@@ -36,7 +36,7 @@ func TestQuicSetup(t *testing.T) {
 				max_streams 100
 			}`,
 			shouldErr:              false,
-			expectedMaxStreams:     pint(100),
+			expectedMaxStreams:     new(100),
 			expectedWorkerPoolSize: nil,
 		},
 		{
@@ -45,7 +45,7 @@ func TestQuicSetup(t *testing.T) {
 			}`,
 			shouldErr:              false,
 			expectedMaxStreams:     nil,
-			expectedWorkerPoolSize: pint(1000),
+			expectedWorkerPoolSize: new(1000),
 		},
 		{
 			input: `quic {
@@ -53,8 +53,8 @@ func TestQuicSetup(t *testing.T) {
 				worker_pool_size 1000
 			}`,
 			shouldErr:              false,
-			expectedMaxStreams:     pint(100),
-			expectedWorkerPoolSize: pint(1000),
+			expectedMaxStreams:     new(100),
+			expectedWorkerPoolSize: new(1000),
 		},
 		{
 			input: `quic {
@@ -133,7 +133,7 @@ func TestQuicSetup(t *testing.T) {
 			}`,
 			shouldErr:          true,
 			expectedErrContent: "already defined",
-			expectedMaxStreams: pint(100),
+			expectedMaxStreams: new(100),
 		},
 		{
 			input: `quic {
@@ -142,7 +142,7 @@ func TestQuicSetup(t *testing.T) {
 			}`,
 			shouldErr:              true,
 			expectedErrContent:     "already defined",
-			expectedWorkerPoolSize: pint(1000),
+			expectedWorkerPoolSize: new(1000),
 		},
 		{
 			input: `quic {
@@ -239,6 +239,4 @@ func formatNilableInt(v *int) string {
 	return fmt.Sprintf("%d", *v)
 }
 
-func pint(i int) *int {
-	return &i
-}
+//go:fix inline

plugin/rewrite/reverter.go

@@ -2,6 +2,7 @@ package rewrite
 
 import (
 	"fmt"
+	"slices"
 
 	"github.com/miekg/dns"
 )
@@ -161,8 +162,8 @@ func copyRRs(rrs []dns.RR) []dns.RR {
 
 func (r *ResponseReverter) rewriteResourceRecord(res *dns.Msg, rr dns.RR) {
 	// The reverting rules need to be done in reversed order.
-	for i := len(r.ResponseRules) - 1; i >= 0; i-- {
-		r.ResponseRules[i].RewriteResponse(res, rr)
+	for _, v := range slices.Backward(r.ResponseRules) {
+		v.RewriteResponse(res, rr)
 	}
 }
 
@@ -171,18 +172,18 @@ func (r *ResponseReverter) rewriteResourceRecord(res *dns.Msg, rr dns.RR) {
 // loops in WriteMsg would otherwise never apply them.
 func (r *ResponseReverter) rewriteMsg(res *dns.Msg) {
 	// The reverting rules need to be done in reversed order.
-	for i := len(r.ResponseRules) - 1; i >= 0; i-- {
-		if _, ok := r.ResponseRules[i].(msgResponseRule); !ok {
+	for _, v := range slices.Backward(r.ResponseRules) {
+		if _, ok := v.(msgResponseRule); !ok {
 			continue
 		}
-		r.ResponseRules[i].RewriteResponse(res, nil)
+		v.RewriteResponse(res, nil)
 	}
 }
 
 func (r *ResponseReverter) rewriteRequestExtra(req *dns.Msg, rr dns.RR) {
 	// The reverting rules need to be done in reversed order.
-	for i := len(r.ResponseRules) - 1; i >= 0; i-- {
-		rule, ok := r.ResponseRules[i].(requestExtraRevertRule)
+	for _, v := range slices.Backward(r.ResponseRules) {
+		rule, ok := v.(requestExtraRevertRule)
 		if !ok {
 			continue
 		}

plugin/siit/siit_test.go

@@ -541,7 +541,7 @@ func TestSIIT(t *testing.T) {
 			}
 			actual := rec.Msg
 			if actual.Rcode != rc {
-				t.Fatalf("ServeDNS should return real result code %q != %q", actual.Rcode, rc)
+				t.Fatalf("ServeDNS should return real result code %d != %d", actual.Rcode, rc)
 			}
 
 			if !reflect.DeepEqual(actual, tc.resp) {

plugin/test/helpers.go

@@ -247,7 +247,7 @@ func Section(tc Case, sec sect, rr []dns.RR) error {
 				return fmt.Errorf("MX Mx should be %q, but is %q", tt.Mx, x.Mx)
 			}
 			if x.Preference != tt.Preference {
-				return fmt.Errorf("MX Preference should be %q, but is %q", tt.Preference, x.Preference)
+				return fmt.Errorf("MX Preference should be %d, but is %d", tt.Preference, x.Preference)
 			}
 		case *dns.NS:
 			tt := section[i].(*dns.NS)