Read the e2e Go version from go.mod and apply the safe go fix modernizers (#4677)

charts/gha-runner-scale-set-controller/tests/metrics_test.go

@@ -66,7 +66,7 @@ func TestControllerMetricsAddress(t *testing.T) {
 
 func indentMetricsValues(values string) string {
 	result := ""
-	for _, line := range strings.Split(strings.TrimSuffix(values, "\n"), "\n") {
+	for line := range strings.SplitSeq(strings.TrimSuffix(values, "\n"), "\n") {
 		result += "  " + line + "\n"
 	}
 	return result

charts/gha-runner-scale-set/tests/template_test.go

@@ -2,6 +2,7 @@ package tests
 
 import (
 	"fmt"
+	"maps"
 	"path/filepath"
 	"strings"
 	"testing"
@@ -210,12 +211,8 @@ func TestTemplateListenerScalerValidation(t *testing.T) {
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
 			setValues := make(map[string]string, len(baseValues)+len(tt.setValues))
-			for key, value := range baseValues {
-				setValues[key] = value
-			}
-			for key, value := range tt.setValues {
-				setValues[key] = value
-			}
+			maps.Copy(setValues, baseValues)
+			maps.Copy(setValues, tt.setValues)
 
 			options := &helm.Options{
 				Logger:         logger.Discard,
@@ -276,12 +273,8 @@ func TestTemplateListenerScalerConfig(t *testing.T) {
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
 			setValues := make(map[string]string, len(baseValues)+len(tt.setValues))
-			for key, value := range baseValues {
-				setValues[key] = value
-			}
-			for key, value := range tt.setValues {
-				setValues[key] = value
-			}
+			maps.Copy(setValues, baseValues)
+			maps.Copy(setValues, tt.setValues)
 
 			options := &helm.Options{
 				Logger:         logger.Discard,

controllers/actions.github.com/ephemeralrunnerset_controller_test.go

@@ -1454,7 +1454,7 @@ var _ = Describe("Test EphemeralRunnerSet controller", func() {
 			).Should(BeEquivalentTo(3), "3 EphemeralRunner should be created")
 
 			idleRunnerNames := map[string]struct{}{}
-			for i := 0; i < 2; i++ {
+			for i := range 2 {
 				idleRunner := runnerList.Items[i].DeepCopy()
 				idleRunner.Status.Phase = v1alpha1.EphemeralRunnerPhaseRunning
 				idleRunner.Status.RunnerID = i + 101

controllers/actions.github.com/predicates_test.go

@@ -470,8 +470,8 @@ func TestPredicateProjectionsCoverEveryStatusField(t *testing.T) {
 	fieldNames := func(v any) []string {
 		typ := reflect.TypeOf(v)
 		names := make([]string, 0, typ.NumField())
-		for i := 0; i < typ.NumField(); i++ {
-			names = append(names, typ.Field(i).Name)
+		for field := range typ.Fields() {
+			names = append(names, field.Name)
 		}
 		sort.Strings(names)
 		return names

go.mod

@@ -28,6 +28,7 @@ require (
 	github.com/teambition/rrule-go v1.8.2
 	go.uber.org/multierr v1.11.0
 	go.uber.org/zap v1.28.0
+	golang.org/x/mod v0.41.0
 	golang.org/x/net v0.59.0
 	golang.org/x/oauth2 v0.37.0
 	golang.org/x/sync v0.23.0
@@ -211,7 +212,6 @@ require (
 	go.yaml.in/yaml/v4 v4.0.0-rc.6 // indirect
 	golang.org/x/crypto v0.57.0 // indirect
 	golang.org/x/exp v0.0.0-20260908205506-85c1c2202aba // indirect
-	golang.org/x/mod v0.41.0 // indirect
 	golang.org/x/sys v0.48.0 // indirect
 	golang.org/x/term v0.46.0 // indirect
 	golang.org/x/text v0.42.0 // indirect

hash/fnv.go

@@ -7,7 +7,7 @@ import (
 	"k8s.io/apimachinery/pkg/util/rand"
 )
 
-func FNVHashStringObjects(objs ...interface{}) string {
+func FNVHashStringObjects(objs ...any) string {
 	hash := fnv.New32a()
 
 	for _, obj := range objs {

hash/hash.go

@@ -16,7 +16,7 @@ import (
 // DeepHashObject writes specified object to hash using the spew library
 // which follows pointers and prints actual values of the nested objects
 // ensuring the hash does not change when a pointer changes.
-func DeepHashObject(hasher hash.Hash, objectToWrite interface{}) {
+func DeepHashObject(hasher hash.Hash, objectToWrite any) {
 	hasher.Reset()
 	printer := spew.ConfigState{
 		Indent:         " ",
@@ -34,7 +34,7 @@ func DeepHashObject(hasher hash.Hash, objectToWrite interface{}) {
 //
 // Proudly modified and adopted from k8s.io/kubernetes/pkg/util/hash.DeepHashObject and
 // k8s.io/kubernetes/pkg/controller.ComputeHash.
-func ComputeTemplateHash(template interface{}) string {
+func ComputeTemplateHash(template any) string {
 	hasher := fnv.New32a()
 
 	hasher.Reset()

logging/logger.go

@@ -4,6 +4,7 @@ import (
 	"errors"
 	"fmt"
 	"os"
+	"slices"
 	"strconv"
 	"time"
 
@@ -78,10 +79,5 @@ func NewLogger(logLevel string, logFormat string) (logr.Logger, error) {
 
 func validLogFormat(logFormat string) bool {
 	validFormat := []string{"text", "json"}
-	for _, v := range validFormat {
-		if v == logFormat {
-			return true
-		}
-	}
-	return false
+	return slices.Contains(validFormat, logFormat)
 }

logging/transport.go

@@ -35,7 +35,7 @@ func (t Transport) log(req *http.Request, resp *http.Response) {
 		return
 	}
 
-	var args []interface{}
+	var args []any
 
 	marked := resp.Header.Get(httpcache.XFromCache) == "1"
 

test/e2e/e2e_test.go

@@ -15,6 +15,7 @@ import (
 	"github.com/google/go-github/v52/github"
 	"github.com/onsi/gomega"
 	"github.com/stretchr/testify/require"
+	"golang.org/x/mod/modfile"
 	"golang.org/x/oauth2"
 	"sigs.k8s.io/yaml"
 )
@@ -1018,7 +1019,7 @@ type job struct {
 func createTestJobs(id, testResultCMNamePrefix string, numJobs int) []job {
 	var testJobs []job
 
-	for i := 0; i < numJobs; i++ {
+	for i := range numJobs {
 		name := fmt.Sprintf("test%d", i)
 		testArg := fmt.Sprintf("%s%d", id, i)
 		configMapName := testResultCMNamePrefix + testArg
@@ -1050,10 +1051,11 @@ func installActionsWorkflow(t *testing.T, testName, runnerLabel, testResultCMNam
 	}
 
 	kubernetesContainerMode := os.Getenv("TEST_CONTAINER_MODE") == "kubernetes"
+	goVersion := goVersionFromGoMod(t)
 
 	var container string
 	if kubernetesContainerMode {
-		container = "golang:1.27.1"
+		container = "golang:" + goVersion
 	}
 
 	for _, j := range testJobs {
@@ -1118,7 +1120,7 @@ func installActionsWorkflow(t *testing.T, testName, runnerLabel, testResultCMNam
 				testing.Step{
 					Uses: "actions/setup-go@v3",
 					With: &testing.With{
-						GoVersion: "1.27.1",
+						GoVersion: goVersion,
 					},
 				},
 			)
@@ -1300,6 +1302,33 @@ kubectl create cm %s$id --from-literal=status=ok
 	}
 }
 
+// goVersionFromGoMod keeps the runner-side Go toolchain in sync with go.mod so
+// the version is pinned in exactly one place. Like setup-go's go-version-file,
+// the toolchain directive wins over the go directive when both are present.
+func goVersionFromGoMod(t *testing.T) string {
+	t.Helper()
+
+	data, err := os.ReadFile(filepath.Join("..", "..", "go.mod"))
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	f, err := modfile.ParseLax("go.mod", data, nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if f.Toolchain != nil {
+		return strings.TrimPrefix(f.Toolchain.Name, "go")
+	}
+
+	if f.Go == nil {
+		t.Fatal("go.mod has no go directive")
+	}
+
+	return f.Go.Version
+}
+
 func verifyActionsWorkflowRun(t *testing.T, ctx context.Context, env *testing.Env, testJobs []job, timeout time.Duration, cmCfg testing.KubectlConfig) {
 	t.Helper()
 

testing/kubectl.go

@@ -122,7 +122,7 @@ func (k *Kubectl) FindPods(ctx context.Context, label string, cfg KubectlConfig)
 	}
 
 	var pods []string
-	for _, l := range strings.Split(out, "\n") {
+	for l := range strings.SplitSeq(out, "\n") {
 		if l != "" {
 			pods = append(pods, l)
 		}

testing/runtime/runtime.go

@@ -26,6 +26,6 @@ func (k Cmdr) CombinedOutput(cmd *exec.Cmd) (string, error) {
 	return string(o), nil
 }
 
-func (k Cmdr) Errorf(f string, args ...interface{}) {
+func (k Cmdr) Errorf(f string, args ...any) {
 	fmt.Fprintf(os.Stderr, f+"\n", args...)
 }