Apply modernize analysis improvements

Signed-off-by: Feruzjon Muyassarov <feruzjon.muyassarov@est.tech>

pkg/apis/nfd/nodefeaturerule/expression.go

@@ -141,7 +141,7 @@ func evaluateMatchExpression(m *nfdv1alpha1.MatchExpression, valid bool, value i
 				return false, fmt.Errorf("not a number %q", value)
 			}
 			lr := make([]int, 2)
-			for i := 0; i < 2; i++ {
+			for i := range 2 {
 				lr[i], err = strconv.Atoi(m.Value[i])
 				if err != nil {
 					return false, fmt.Errorf("not a number %q in %v", m.Value[i], m)

pkg/apis/nfd/template/template.go

@@ -57,7 +57,7 @@ func (h *Helper) ExpandMap(data interface{}) (map[string]string, error) {
 
 	// Split out individual key-value pairs
 	out := make(map[string]string)
-	for _, item := range strings.Split(expanded, "\n") {
+	for item := range strings.SplitSeq(expanded, "\n") {
 		// Remove leading/trailing whitespace and skip empty lines
 		if trimmed := strings.TrimSpace(item); trimmed != "" {
 			split := strings.SplitN(trimmed, "=", 2)

pkg/kubectl-nfd/dryrun.go

@@ -18,6 +18,7 @@ package kubectlnfd
 
 import (
 	"fmt"
+	"maps"
 	"os"
 	"strings"
 
@@ -106,9 +107,7 @@ func processNodeFeatureRule(nodeFeatureRule nfdv1alpha1.NodeFeatureRule, nodeFea
 			extendedResources[k] = v
 		}
 		// annotations
-		for k, v := range ruleOut.Annotations {
+		maps.Copy(annotations, ruleOut.Annotations)
-			annotations[k] = v
-		}
 	}
 
 	if len(taints) > 0 {

pkg/nfd-gc/nfd-gc_test.go

@@ -141,7 +141,7 @@ func shouldEventuallyHaveNRTs(actualI interface{}, expectedI ...interface{}) str
 	}
 	actual := sets.Set[string]{}
 	gvr := topologyv1alpha2.SchemeGroupVersion.WithResource("noderesourcetopologies")
-	for i := 0; i < 2; i++ {
+	for range 2 {
 		rsp, err := cli.Resource(gvr).List(context.TODO(), metav1.ListOptions{})
 		if err != nil {
 			return fmt.Sprintf("failed to list: %v", err)

pkg/nfd-master/updater-pool.go

@@ -151,7 +151,7 @@ func (u *updaterPool) start(parallelism int) {
 	u.queue = workqueue.NewTypedRateLimitingQueue[string](rl)
 	u.nfgQueue = workqueue.NewTypedRateLimitingQueue[string](rl)
 
-	for i := 0; i < parallelism; i++ {
+	for range parallelism {
 		u.wg.Add(1)
 		go u.runNodeUpdater()
 		u.nfgWg.Add(1)

pkg/utils/featuregate/featuregate.go

@@ -19,6 +19,7 @@ package featuregate
 import (
 	"flag"
 	"fmt"
+	"maps"
 	"sort"
 	"strconv"
 	"strings"
@@ -130,7 +131,7 @@ func NewFeatureGate() *featureGate {
 // map[string]bool of known keys or returns an error.
 func (f *featureGate) Set(value string) error {
 	m := make(map[string]bool)
-	for _, s := range strings.Split(value, ",") {
+	for s := range strings.SplitSeq(value, ",") {
 		if len(s) == 0 {
 			continue
 		}
@@ -156,9 +157,8 @@ func (f *featureGate) SetFromMap(m map[string]bool) error {
 
 	// Copy existing state
 	known := map[Feature]FeatureSpec{}
-	for k, v := range f.known.Load().(map[Feature]FeatureSpec) {
+	maps.Copy(known, f.known.Load().(map[Feature]FeatureSpec))
-		known[k] = v
+
-	}
 	enabled := map[Feature]bool{}
 	for k, v := range f.enabled.Load().(map[Feature]bool) {
 		enabled[k] = v
@@ -317,13 +317,9 @@ func (f *featureGate) KnownFeatures() []string {
 func (f *featureGate) DeepCopy() MutableFeatureGate {
 	// Copy existing state.
 	known := map[Feature]FeatureSpec{}
-	for k, v := range f.known.Load().(map[Feature]FeatureSpec) {
+	maps.Copy(known, f.known.Load().(map[Feature]FeatureSpec))
-		known[k] = v
-	}
 	enabled := map[Feature]bool{}
-	for k, v := range f.enabled.Load().(map[Feature]bool) {
+	maps.Copy(enabled, f.enabled.Load().(map[Feature]bool))
-		enabled[k] = v
-	}
 
 	// Construct a new featureGate around the copied state.
 	// Note that specialFeatures is treated as immutable by convention,

pkg/utils/flags.go

@@ -49,7 +49,7 @@ type StringSetVal map[string]struct{}
 // Set implements the flag.Value interface
 func (a *StringSetVal) Set(val string) error {
 	m := map[string]struct{}{}
-	for _, n := range strings.Split(val, ",") {
+	for n := range strings.SplitSeq(val, ",") {
 		m[n] = struct{}{}
 	}
 	*a = m

pkg/utils/memory_resources.go

@@ -128,7 +128,7 @@ func readTotalMemoryFromMeminfo(path string) (int64, error) {
 		return -1, err
 	}
 
-	for _, line := range strings.Split(string(data), "\n") {
+	for line := range strings.SplitSeq(string(data), "\n") {
 		split := strings.SplitN(line, ":", 2)
 		if len(split) != 2 {
 			continue

pkg/utils/memory_resources_test.go

@@ -118,7 +118,7 @@ func TestGetMemoryResourceCounters(t *testing.T) {
 }
 
 func makeMemoryTree(root string, numNodes int) error {
-	for idx := 0; idx < numNodes; idx++ {
+	for idx := range numNodes {
 		path := filepath.Join(
 			root,
 			fmt.Sprintf("node%d", idx),
@@ -136,7 +136,7 @@ func makeMemoryTree(root string, numNodes int) error {
 }
 
 func makeHugepagesTree(root string, numNodes int) error {
-	for idx := 0; idx < numNodes; idx++ {
+	for idx := range numNodes {
 		for _, size := range []int{HugepageSize2Mi, HugepageSize1Gi} {
 			path := filepath.Join(
 				root,
@@ -163,5 +163,5 @@ func setHPCount(root string, nodeID, pageSize, numPages int) error {
 		fmt.Sprintf("hugepages-%dkB", pageSize),
 		"nr_hugepages",
 	)
-	return os.WriteFile(path, []byte(fmt.Sprintf("%d", numPages)), 0644)
+	return os.WriteFile(path, fmt.Appendf(nil, "%d", numPages), 0644)
 }

source/custom/api/expression.go

@@ -69,7 +69,7 @@ func (m *MatchExpression) Validate() error {
 		}
 		var err error
 		v := make([]int, 2)
-		for i := 0; i < 2; i++ {
+		for i := range 2 {
 			if v[i], err = strconv.Atoi(m.Value[i]); err != nil {
 				return fmt.Errorf("value must contain integers for Op %q (have %v)", m.Op, m.Value)
 			}

source/kernel/kconfig.go

@@ -100,8 +100,8 @@ func parseKconfig(configPath string) (realKconfig, legacyKconfig map[string]stri
 	}
 
 	// Process data, line-by-line
-	lines := bytes.Split(raw, []byte("\n"))
+	lines := bytes.SplitSeq(raw, []byte("\n"))
-	for _, line := range lines {
+	for line := range lines {
 		str := string(line)
 		if strings.HasPrefix(str, "CONFIG_") {
 			split := strings.SplitN(str, "=", 2)

source/memory/memory.go

@@ -265,7 +265,7 @@ func getNumberOfNonEmptyLinesFromFile(path string) (int, error) {
 		return 0, err
 	}
 	length := 0
-	for _, line := range strings.Split(string(data), "\n") {
+	for line := range strings.SplitSeq(string(data), "\n") {
 		if strings.TrimSpace(line) != "" {
 			length++
 		}

source/usb/utils.go

@@ -18,6 +18,7 @@ package usb
 
 import (
 	"fmt"
+	"maps"
 	"os"
 	"path"
 	"path/filepath"
@@ -90,9 +91,7 @@ func readUsbDevInfo(devPath string) ([]nfdv1alpha1.InstanceFeature, error) {
 			}
 
 			subdevAttrs := make(map[string]string, len(attrs))
-			for k, v := range attrs {
+			maps.Copy(subdevAttrs, attrs)
-				subdevAttrs[k] = v
-			}
 			subdevAttrs["class"] = attrVal
 
 			instances = append(instances, *nfdv1alpha1.NewInstanceFeature(subdevAttrs))

test/e2e/node_feature_discovery_test.go

@@ -63,19 +63,19 @@ func cleanupNode(ctx context.Context, cs clientset.Interface) {
 		updateStatus := false
 		// Gather info about all NFD-managed node assets outside the default prefix
 		nfdLabels := map[string]struct{}{}
-		for _, name := range strings.Split(node.Annotations[nfdv1alpha1.FeatureLabelsAnnotation], ",") {
+		for name := range strings.SplitSeq(node.Annotations[nfdv1alpha1.FeatureLabelsAnnotation], ",") {
 			if strings.Contains(name, "/") {
 				nfdLabels[name] = struct{}{}
 			}
 		}
 		nfdAnnotations := map[string]struct{}{}
-		for _, name := range strings.Split(node.Annotations[nfdv1alpha1.FeatureAnnotationsTrackingAnnotation], ",") {
+		for name := range strings.SplitSeq(node.Annotations[nfdv1alpha1.FeatureAnnotationsTrackingAnnotation], ",") {
 			if strings.Contains(name, "/") {
 				nfdAnnotations[name] = struct{}{}
 			}
 		}
 		nfdERs := map[string]struct{}{}
-		for _, name := range strings.Split(node.Annotations[nfdv1alpha1.ExtendedResourceAnnotation], ",") {
+		for name := range strings.SplitSeq(node.Annotations[nfdv1alpha1.ExtendedResourceAnnotation], ",") {
 			if strings.Contains(name, "/") {
 				nfdERs[name] = struct{}{}
 			}
@@ -142,7 +142,7 @@ func cleanupNode(ctx context.Context, cs clientset.Interface) {
 
 	for _, n := range nodeList.Items {
 		var err error
-		for retry := 0; retry < 5; retry++ {
+		for range 5 {
 			if err = cleanup(n.Name); err == nil {
 				break
 			}