all: use Go 1.22 range-over-int

Updates #11058

Change-Id: I35e7ef9b90e83cac04ca93fd964ad00ed5b48430
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>

types/ipproto/ipproto_test.go

@@ -49,7 +49,7 @@ func TestAcceptedNamesContainsPreferredNames(t *testing.T) {
 }
 
 func TestProtoTextEncodingRoundTrip(t *testing.T) {
-	for i := 0; i < 256; i++ {
+	for i := range 256 {
 		text := must.Get(Proto(i).MarshalText())
 		var p Proto
 		must.Do(p.UnmarshalText(text))
@@ -67,7 +67,7 @@ func TestProtoUnmarshalText(t *testing.T) {
 		t.Fatalf("empty input, got err=%v, p=%v, want nil, 0", err, p)
 	}
 
-	for i := 0; i < 256; i++ {
+	for i := range 256 {
 		var p Proto
 		must.Do(p.UnmarshalText([]byte(fmt.Sprintf("%d", i))))
 		if got, want := p, Proto(i); got != want {
@@ -93,7 +93,7 @@ func TestProtoUnmarshalText(t *testing.T) {
 }
 
 func TestProtoMarshalText(t *testing.T) {
-	for i := 0; i < 256; i++ {
+	for i := range 256 {
 		text := must.Get(Proto(i).MarshalText())
 
 		if wantName, ok := preferredNames[Proto(i)]; ok {
@@ -110,7 +110,7 @@ func TestProtoMarshalText(t *testing.T) {
 }
 
 func TestProtoMarshalJSON(t *testing.T) {
-	for i := 0; i < 256; i++ {
+	for i := range 256 {
 		j := must.Get(Proto(i).MarshalJSON())
 		if got, want := string(j), fmt.Sprintf(`%d`, i); got != want {
 			t.Errorf("Proto(%d).MarshalJSON() = %q, want %q", i, got, want)
@@ -121,7 +121,7 @@ func TestProtoMarshalJSON(t *testing.T) {
 func TestProtoUnmarshalJSON(t *testing.T) {
 	var p Proto
 
-	for i := 0; i < 256; i++ {
+	for i := range 256 {
 		j := []byte(fmt.Sprintf(`%d`, i))
 		must.Do(json.Unmarshal(j, &p))
 		if got, want := p, Proto(i); got != want {

types/key/node_test.go

@@ -162,7 +162,7 @@ func TestChallenge(t *testing.T) {
 func TestShard(t *testing.T) {
 	const N = 1_000
 	var shardCount [256]int
-	for i := 0; i < N; i++ {
+	for range N {
 		shardCount[NewNode().Public().Shard()]++
 	}
 	e := float64(N) / 256 // expected

types/key/util_test.go

@@ -22,7 +22,7 @@ func TestRand(t *testing.T) {
 }
 
 func TestClamp25519Private(t *testing.T) {
-	for i := 0; i < 100; i++ {
+	for range 100 {
 		var k [32]byte
 		rand(k[:])
 		clamp25519Private(k[:])

types/lazy/sync_test.go

@@ -89,7 +89,7 @@ func TestSyncValueConcurrent(t *testing.T) {
 		routines = 10000
 	)
 	wg.Add(routines)
-	for i := 0; i < routines; i++ {
+	for range routines {
 		go func() {
 			defer wg.Done()
 			// Every goroutine waits for the go signal, so that more of them

types/logger/logger_test.go

@@ -70,7 +70,7 @@ func TestRateLimiter(t *testing.T) {
 	lgtest := logTester(want, t, &testsRun)
 	lg := RateLimitedFnWithClock(lgtest, 1*time.Minute, 2, 50, nowf)
 	var prefixed Logf
-	for i := 0; i < 10; i++ {
+	for i := range 10 {
 		lg("boring string with constant formatting %s", "(constant)")
 		lg("templated format string no. %d", i)
 		if i == 4 {
@@ -121,7 +121,7 @@ func TestLogOnChange(t *testing.T) {
 	lgtest := logTester(want, t, &testsRun)
 	lg := LogOnChange(lgtest, 5*time.Second, timeNow)
 
-	for i := 0; i < 10; i++ {
+	for range 10 {
 		lg("%s", "1 2 3 4 5 6")
 	}
 	lg("1 2 3 4 5 7")

types/netmap/netmap.go

@@ -137,7 +137,7 @@ func (nm *NetworkMap) PeerByTailscaleIP(ip netip.Addr) (peer tailcfg.NodeView, o
 	}
 	for _, n := range nm.Peers {
 		ad := n.Addresses()
-		for i := 0; i < ad.Len(); i++ {
+		for i := range ad.Len() {
 			a := ad.At(i)
 			if a.Addr() == ip {
 				return n, true

types/netmap/nodemut.go

@@ -73,7 +73,7 @@ func (m NodeMutationLastSeen) Apply(n *tailcfg.Node) {
 var peerChangeFields = sync.OnceValue(func() []reflect.StructField {
 	var fields []reflect.StructField
 	rt := reflect.TypeFor[tailcfg.PeerChange]()
-	for i := 0; i < rt.NumField(); i++ {
+	for i := range rt.NumField() {
 		fields = append(fields, rt.Field(i))
 	}
 	return fields

types/netmap/nodemut_test.go

@@ -44,7 +44,7 @@ func TestMapResponseContainsNonPatchFields(t *testing.T) {
 	}
 
 	rt := reflect.TypeFor[tailcfg.MapResponse]()
-	for i := 0; i < rt.NumField(); i++ {
+	for i := range rt.NumField() {
 		f := rt.Field(i)
 
 		var want bool

types/persist/persist_test.go

@@ -12,7 +12,7 @@ import (
 )
 
 func fieldsOf(t reflect.Type) (fields []string) {
-	for i := 0; i < t.NumField(); i++ {
+	for i := range t.NumField() {
 		if name := t.Field(i).Name; name != "_" {
 			fields = append(fields, name)
 		}

types/views/views.go

@@ -262,7 +262,7 @@ func (v Slice[T]) AsSlice() []T {
 //
 // As it runs in O(n) time, use with care.
 func (v Slice[T]) IndexFunc(f func(T) bool) int {
-	for i := 0; i < v.Len(); i++ {
+	for i := range v.Len() {
 		if f(v.At(i)) {
 			return i
 		}

types/views/views_test.go

@@ -24,7 +24,7 @@ type viewStruct struct {
 
 func BenchmarkSliceIteration(b *testing.B) {
 	var data []viewStruct
-	for i := 0; i < 10000; i++ {
+	for i := range 10000 {
 		data = append(data, viewStruct{Int: i})
 	}
 	b.ResetTimer()
@@ -33,7 +33,7 @@ func BenchmarkSliceIteration(b *testing.B) {
 		dv := SliceOf(data)
 		for it := 0; it < b.N; it++ {
 			sum := 0
-			for i := 0; i < dv.Len(); i++ {
+			for i := range dv.Len() {
 				sum += dv.At(i).Int
 			}
 		}
@@ -181,7 +181,7 @@ func TestSliceMapKey(t *testing.T) {
 	}
 
 	wantDiff := []Slice[string]{nilSlice, empty, sub1, sub2, sub3, u3}
-	for i := 0; i < len(wantDiff); i++ {
+	for i := range len(wantDiff) {
 		for j := i + 1; j < len(wantDiff); j++ {
 			si, sj := wantDiff[i], wantDiff[j]
 			ki, kj := wantDiff[i].MapKey(), wantDiff[j].MapKey()