Apply go fix modernizations

fuzz_test.go

@@ -60,10 +60,7 @@ func FuzzBuildParseRoundtrip(f *testing.F) {
 		if dataPkt.Universe != universe {
 			t.Fatalf("universe mismatch: sent %d, got %d", universe, dataPkt.Universe)
 		}
-		expectedLen := len(dmxInput)
+		expectedLen := min(len(dmxInput), 512)
-		if expectedLen > 512 {
-			expectedLen = 512
-		}
 		if !bytes.Equal(dataPkt.Data[:expectedLen], dmxInput[:expectedLen]) {
 			t.Fatalf("dmx data mismatch")
 		}

protocol.go

@@ -58,7 +58,7 @@ func MulticastAddr(universe uint16) *net.UDPAddr {
 	}
 }
 
-func ParsePacket(data []byte) (interface{}, error) {
+func ParsePacket(data []byte) (any, error) {
 	if len(data) < 22 {
 		return nil, ErrPacketTooShort
 	}
@@ -99,10 +99,7 @@ func parseDataPacket(data []byte) (*DataPacket, error) {
 		return nil, ErrPacketTooShort
 	}
 
-	dmxLen := int(propCount) - 1
+	dmxLen := min(int(propCount)-1, 512)
-	if dmxLen > 512 {
-		dmxLen = 512
-	}
 
 	if len(data) < 126+dmxLen {
 		return nil, ErrPacketTooShort
@@ -121,7 +118,7 @@ func parseDataPacket(data []byte) (*DataPacket, error) {
 	return pkt, nil
 }
 
-func parseExtendedPacket(data []byte) (interface{}, error) {
+func parseExtendedPacket(data []byte) (any, error) {
 	if len(data) < 118 {
 		return nil, ErrPacketTooShort
 	}
@@ -149,7 +146,7 @@ func parseExtendedPacket(data []byte) (interface{}, error) {
 
 	universeCount := (len(data) - 120) / 2
 	pkt.Universes = make([]uint16, 0, universeCount)
-	for i := 0; i < universeCount; i++ {
+	for i := range universeCount {
 		u := binary.BigEndian.Uint16(data[120+i*2 : 122+i*2])
 		if u >= 1 && u <= 63999 {
 			pkt.Universes = append(pkt.Universes, u)
@@ -160,10 +157,7 @@ func parseExtendedPacket(data []byte) (interface{}, error) {
 }
 
 func BuildDataPacket(universe uint16, sequence uint8, sourceName string, cid [16]byte, data []byte) []byte {
-	dataLen := len(data)
+	dataLen := min(len(data), 512)
-	if dataLen > 512 {
-		dataLen = 512
-	}
 
 	pktLen := 126 + dataLen
 	buf := make([]byte, pktLen)
@@ -200,10 +194,7 @@ func BuildDataPacket(universe uint16, sequence uint8, sourceName string, cid [16
 }
 
 func BuildDiscoveryPacket(sourceName string, cid [16]byte, page, lastPage uint8, universes []uint16) []byte {
-	universeCount := len(universes)
+	universeCount := min(len(universes), 512)
-	if universeCount > 512 {
-		universeCount = 512
-	}
 
 	pktLen := 120 + universeCount*2
 	buf := make([]byte, pktLen)

receiver.go

@@ -9,7 +9,7 @@ import (
 
 type Receiver struct {
 	conn    *multicast.Conn
-	handler func(src *net.UDPAddr, pkt interface{})
+	handler func(src *net.UDPAddr, pkt any)
 	done    chan struct{}
 }
 
@@ -60,7 +60,7 @@ func NewDiscoveryReceiver(iface *net.Interface) (*Receiver, error) {
 	}, nil
 }
 
-func (r *Receiver) SetHandler(fn func(src *net.UDPAddr, pkt interface{})) {
+func (r *Receiver) SetHandler(fn func(src *net.UDPAddr, pkt any)) {
 	r.handler = fn
 }
 

sender.go

@@ -3,7 +3,7 @@ package sacn
 import (
 	"crypto/rand"
 	"net"
-	"sort"
+	"slices"
 	"sync"
 	"time"
 
@@ -128,17 +128,14 @@ func (s *Sender) sendDiscovery() {
 		return
 	}
 
-	sort.Slice(universes, func(i, j int) bool { return universes[i] < universes[j] })
+	slices.Sort(universes)
 
 	const maxPerPage = 512
 	totalPages := (len(universes) + maxPerPage - 1) / maxPerPage
 
-	for page := 0; page < totalPages; page++ {
+	for page := range totalPages {
 		start := page * maxPerPage
-		end := start + maxPerPage
+		end := min(start+maxPerPage, len(universes))
-		if end > len(universes) {
-			end = len(universes)
-		}
 		pkt := BuildDiscoveryPacket(s.sourceName, s.cid, uint8(page), uint8(totalPages-1), universes[start:end])
 		s.conn.WriteToUDP(pkt, DiscoveryAddr)
 	}