lint: enable intrange linter (#7331)

Enable intrange linter to enforce modern Go range syntax over
traditional for loops, by converting:

for i := 0; i < n; i++

to:

for i := range n

Adding type conversions where needed for compatibility
with existing uint64 parameters.

Signed-off-by: Ville Vesilehto <ville@vesilehto.fi>

test/compression_scrub_test.go

@@ -46,7 +46,7 @@ func TestCompressScrub(t *testing.T) {
 	// compression. This means we're looking for a combo where the pointers is detected and the offset is 12
 	// the position of the first name after the header. The erratic plugin adds 30 RRs that should all be compressed.
 	found := 0
-	for i := 0; i < len(buf)-1; i++ {
+	for i := range len(buf) - 1 {
 		if buf[i]&0xC0 == 0xC0 {
 			off := (int(buf[i])^0xC0)<<8 | int(buf[i+1])
 			if off == 12 {

test/file_xfr_test.go

@@ -17,7 +17,7 @@ func TestLargeAXFR(t *testing.T) {
 	const numAAAAs = 6553
 	sb.WriteString("example.com. IN SOA . . 1 60 60 60 60\n")
 	sb.WriteString("example.com. IN NS ns.example.\n")
-	for i := 0; i < numAAAAs; i++ {
+	for i := range numAAAAs {
 		sb.WriteString(fmt.Sprintf("%d.example.com. IN AAAA 2001:db8::1\n", i))
 	}
 

test/metrics_test.go

@@ -163,7 +163,7 @@ func TestMetricsRewriteRequestSize(t *testing.T) {
 	}
 
 	// Send multiple requests
-	for i := 0; i < numRequests; i++ {
+	for range numRequests {
 		if _, err = dns.Exchange(m, udp); err != nil {
 			t.Fatalf("Could not send message: %s", err)
 		}
@@ -195,7 +195,7 @@ func TestMetricsRewriteRequestSize(t *testing.T) {
 	defer srv2.Stop()
 
 	// Send the same requests with rewrite
-	for i := 0; i < numRequests; i++ {
+	for range numRequests {
 		if _, err = dns.Exchange(m, udp2); err != nil {
 			t.Fatalf("Could not send message: %s", err)
 		}

test/proxy_health_test.go

@@ -65,7 +65,7 @@ func TestProxyThreeWay(t *testing.T) {
 	c := new(dns.Client)
 	c.Timeout = 10 * time.Millisecond
 
-	for i := 0; i < 10; i++ {
+	for range 10 {
 		r, _, err := c.Exchange(m, addr)
 		if err != nil {
 			continue

test/proxy_test.go

@@ -71,7 +71,7 @@ func BenchmarkProxyLookup(b *testing.B) {
 	m.SetQuestion("example.org.", dns.TypeA)
 
 	b.ResetTimer()
-	for i := 0; i < b.N; i++ {
+	for range b.N {
 		if _, err := dns.Exchange(m, udp); err != nil {
 			b.Fatal("Expected to receive reply, but didn't")
 		}

test/quic_test.go

@@ -157,7 +157,7 @@ func TestQUICStreamLimits(t *testing.T) {
 	streamsMu := sync.Mutex{}
 
 	// Attempt to open exactly the configured number of streams
-	for i := 0; i < streamCount; i++ {
+	for i := range streamCount {
 		wg.Add(1)
 		go func(idx int) {
 			defer wg.Done()
@@ -237,7 +237,7 @@ func TestQUICStreamLimits(t *testing.T) {
 	done := make(chan struct{})
 
 	// Launch goroutines to attempt opening additional streams
-	for i := 0; i < extraCount; i++ {
+	for i := range extraCount {
 		extraWg.Add(1)
 		go func(idx int) {
 			defer extraWg.Done()

test/reload_test.go

@@ -181,7 +181,7 @@ func TestReloadSeveralTimeMetrics(t *testing.T) {
 		t.Errorf("Prometheus is not listening : %s", err)
 	}
 	reloadCount := 2
-	for i := 0; i < reloadCount; i++ {
+	for i := range reloadCount {
 		serverReload, err := serverWithMetrics.Restart(
 			NewInput(corefileWithMetrics),
 		)
@@ -305,7 +305,7 @@ func TestMetricsAvailableAfterReloadAndFailedReload(t *testing.T) {
 		t.Errorf("Could not scrap one of expected stats : %s", err)
 	}
 
-	for i := 0; i < 2; i++ {
+	for range 2 {
 		// now provide a failed reload
 		invInst, err := inst.Restart(
 			NewInput(invalidCorefileWithMetrics),

test/secondary_test.go

@@ -72,7 +72,7 @@ func TestSecondaryZoneTransfer(t *testing.T) {
 
 	var r *dns.Msg
 	// This is now async; we need to wait for it to be transferred.
-	for i := 0; i < 10; i++ {
+	for range 10 {
 		r, _ = dns.Exchange(m, udp)
 		if len(r.Answer) != 0 {
 			break
@@ -114,7 +114,7 @@ func TestIxfrResponse(t *testing.T) {
 	c := new(dns.Client)
 	c.Net = "tcp"
 	// This is now async; we need to wait for it to be transferred.
-	for i := 0; i < 10; i++ {
+	for range 10 {
 		r, _, _ = c.Exchange(m, tcp)
 		if len(r.Answer) != 0 {
 			break

test/server_test.go

@@ -127,7 +127,7 @@ func TestMultiZoneBlockConfigs(t *testing.T) {
 		server *caddy.Instance
 		err    error
 	)
-	for j := 0; j < 3; j++ {
+	for j := range 3 {
 		corefile := `.:%d .:%d .:%d {
 		debug
 	}`
@@ -150,7 +150,7 @@ func TestMultiZoneBlockConfigs(t *testing.T) {
 	configs := reflect.ValueOf(ctxVal2.Interface()).Elem().FieldByName("configs")
 	configs2 := reflect.NewAt(configs.Type(), unsafe.Pointer(configs.UnsafeAddr())).Elem()
 
-	for i := 0; i < 3; i++ {
+	for i := range 3 {
 		v := configs2.Index(i)
 		config := v.Interface().(*dnsserver.Config)
 		if !config.Debug {