all: adopt slices helpers

cmd/headscale/cli/root.go

@@ -3,6 +3,7 @@ package cli
 import (
 	"os"
 	"runtime"
+	"slices"
 	"strings"
 
 	"github.com/juanfont/headscale/hscontrol/types"
@@ -95,13 +96,9 @@ func initConfig() {
 var prereleases = []string{"alpha", "beta", "rc", "dev"}
 
 func isPreReleaseVersion(version string) bool {
-	for _, unstable := range prereleases {
-		if strings.Contains(version, unstable) {
-			return true
-		}
-	}
-
-	return false
+	return slices.ContainsFunc(prereleases, func(unstable string) bool {
+		return strings.Contains(version, unstable)
+	})
 }
 
 // filterPreReleasesIfStable returns a function that filters out

cmd/headscale/cli/utils.go

@@ -7,6 +7,7 @@ import (
 	"errors"
 	"fmt"
 	"os"
+	"slices"
 	"time"
 
 	v1 "github.com/juanfont/headscale/gen/go/headscale/v1"
@@ -318,13 +319,9 @@ func printError(err error, outputFormat string) {
 }
 
 func hasMachineOutputFlag() bool {
-	for _, arg := range os.Args {
-		if arg == outputFormatJSON || arg == outputFormatJSONLine || arg == outputFormatYAML {
-			return true
-		}
-	}
-
-	return false
+	return slices.ContainsFunc(os.Args, func(arg string) bool {
+		return arg == outputFormatJSON || arg == outputFormatJSONLine || arg == outputFormatYAML
+	})
 }
 
 type tokenAuth struct {

cmd/hi/stats.go

@@ -1,12 +1,13 @@
 package main
 
 import (
+	"cmp"
 	"context"
 	"encoding/json"
 	"errors"
 	"fmt"
 	"log"
-	"sort"
+	"slices"
 	"strings"
 	"sync"
 	"time"
@@ -390,8 +391,8 @@ func (sc *StatsCollector) GetSummary() []ContainerStatsSummary {
 	}
 
 	// Sort by container name for consistent output
-	sort.Slice(summaries, func(i, j int) bool {
-		return summaries[i].ContainerName < summaries[j].ContainerName
+	slices.SortFunc(summaries, func(a, b ContainerStatsSummary) int {
+		return cmp.Compare(a.ContainerName, b.ContainerName)
 	})
 
 	return summaries
@@ -408,14 +409,8 @@ func calculateStatsSummary(values []float64) StatsSummary {
 	sum := 0.0
 
 	for _, value := range values {
-		if value < minVal {
-			minVal = value
-		}
-
-		if value > maxVal {
-			maxVal = value
-		}
-
+		minVal = min(minVal, value)
+		maxVal = max(maxVal, value)
 		sum += value
 	}
 

hscontrol/capver/capver.go

@@ -3,10 +3,11 @@ package capver
 //go:generate go run ../../tools/capver/main.go
 
 import (
+	"maps"
+	"slices"
 	"sort"
 	"strings"
 
-	xmaps "golang.org/x/exp/maps"
 	"tailscale.com/tailcfg"
 	"tailscale.com/util/set"
 )
@@ -25,10 +26,7 @@ func CanOldCodeBeCleanedUp() {
 }
 
 func tailscaleVersSorted() []string {
-	vers := xmaps.Keys(tailscaleToCapVer)
-	sort.Strings(vers)
-
-	return vers
+	return slices.Sorted(maps.Keys(tailscaleToCapVer))
 }
 
 // TailscaleVersion returns the Tailscale version for the given [tailcfg.CapabilityVersion].

hscontrol/db/node.go

@@ -1,10 +1,11 @@
 package db
 
 import (
+	"cmp"
 	"errors"
 	"fmt"
 	"net/netip"
-	"sort"
+	"slices"
 	"strconv"
 	"sync"
 	"testing"
@@ -68,7 +69,7 @@ func ListPeers(tx *gorm.DB, nodeID types.NodeID, peerIDs ...types.NodeID) (types
 		return types.Nodes{}, err
 	}
 
-	sort.Slice(nodes, func(i, j int) bool { return nodes[i].ID < nodes[j].ID })
+	slices.SortFunc(nodes, func(a, b *types.Node) int { return cmp.Compare(a.ID, b.ID) })
 
 	return nodes, nil
 }

hscontrol/db/sqliteconfig/config.go

@@ -5,6 +5,7 @@ package sqliteconfig
 import (
 	"errors"
 	"fmt"
+	"slices"
 	"strings"
 )
 
@@ -90,15 +91,15 @@ const (
 	JournalModeOff JournalMode = "OFF"
 )
 
+// validJournalModes lists the accepted JournalMode values.
+var validJournalModes = []JournalMode{
+	JournalModeWAL, JournalModeDelete, JournalModeTruncate,
+	JournalModePersist, JournalModeMemory, JournalModeOff,
+}
+
 // IsValid returns true if the JournalMode is valid.
 func (j JournalMode) IsValid() bool {
-	switch j {
-	case JournalModeWAL, JournalModeDelete, JournalModeTruncate,
-		JournalModePersist, JournalModeMemory, JournalModeOff:
-		return true
-	default:
-		return false
-	}
+	return slices.Contains(validJournalModes, j)
 }
 
 // AutoVacuum represents SQLite auto_vacuum pragma values.
@@ -142,14 +143,14 @@ const (
 	AutoVacuumIncremental AutoVacuum = "INCREMENTAL"
 )
 
+// validAutoVacuums lists the accepted AutoVacuum values.
+var validAutoVacuums = []AutoVacuum{
+	AutoVacuumNone, AutoVacuumFull, AutoVacuumIncremental,
+}
+
 // IsValid returns true if the AutoVacuum is valid.
 func (a AutoVacuum) IsValid() bool {
-	switch a {
-	case AutoVacuumNone, AutoVacuumFull, AutoVacuumIncremental:
-		return true
-	default:
-		return false
-	}
+	return slices.Contains(validAutoVacuums, a)
 }
 
 // Synchronous represents SQLite synchronous pragma values.
@@ -201,14 +202,14 @@ const (
 	SynchronousExtra Synchronous = "EXTRA"
 )
 
+// validSynchronous lists the accepted Synchronous values.
+var validSynchronous = []Synchronous{
+	SynchronousOff, SynchronousNormal, SynchronousFull, SynchronousExtra,
+}
+
 // IsValid returns true if the Synchronous is valid.
 func (s Synchronous) IsValid() bool {
-	switch s {
-	case SynchronousOff, SynchronousNormal, SynchronousFull, SynchronousExtra:
-		return true
-	default:
-		return false
-	}
+	return slices.Contains(validSynchronous, s)
 }
 
 // TxLock represents SQLite transaction lock mode.
@@ -252,14 +253,15 @@ const (
 	TxLockExclusive TxLock = "exclusive"
 )
 
+// validTxLocks lists the accepted TxLock values; the empty string is valid
+// and selects the driver default.
+var validTxLocks = []TxLock{
+	TxLockDeferred, TxLockImmediate, TxLockExclusive, "",
+}
+
 // IsValid returns true if the TxLock is valid.
 func (t TxLock) IsValid() bool {
-	switch t {
-	case TxLockDeferred, TxLockImmediate, TxLockExclusive, "":
-		return true
-	default:
-		return false
-	}
+	return slices.Contains(validTxLocks, t)
 }
 
 // Config holds SQLite database configuration with type-safe enums.

hscontrol/debug.go

@@ -1,12 +1,14 @@
 package hscontrol
 
 import (
+	"cmp"
 	"context"
 	"encoding/json"
 	"fmt"
 	"net"
 	"net/http"
 	"net/netip"
+	"slices"
 	"strings"
 	"time"
 
@@ -262,13 +264,9 @@ func (h *Headscale) debugBatcher() string {
 	}
 
 	// Sort by node ID
-	for i := 0; i < len(nodes); i++ {
-		for j := i + 1; j < len(nodes); j++ {
-			if nodes[i].id > nodes[j].id {
-				nodes[i], nodes[j] = nodes[j], nodes[i]
-			}
-		}
-	}
+	slices.SortFunc(nodes, func(a, b nodeStatus) int {
+		return cmp.Compare(a.id, b.id)
+	})
 
 	// Output sorted nodes
 	for _, node := range nodes {

hscontrol/handlers.go

@@ -148,20 +148,12 @@ func (h *Headscale) handleVerifyRequest(
 		return NewHTTPError(http.StatusBadRequest, "Bad Request: invalid JSON", fmt.Errorf("parsing DERP client request: %w", err))
 	}
 
-	nodes := h.state.ListNodes()
-
-	// Check if any node has the requested NodeKey
-	var nodeKeyFound bool
-
-	for _, node := range nodes.All() {
-		if node.NodeKey() == derpAdmitClientRequest.NodePublic {
-			nodeKeyFound = true
-			break
-		}
-	}
+	allow := h.state.ListNodes().ContainsFunc(func(n types.NodeView) bool {
+		return n.NodeKey() == derpAdmitClientRequest.NodePublic
+	})
 
 	resp := &tailcfg.DERPAdmitClientResponse{
-		Allow: nodeKeyFound,
+		Allow: allow,
 	}
 
 	return json.NewEncoder(writer).Encode(resp)

hscontrol/mapper/builder.go

@@ -1,9 +1,9 @@
 package mapper
 
 import (
+	"cmp"
 	"net/netip"
 	"slices"
-	"sort"
 	"time"
 
 	"github.com/juanfont/headscale/hscontrol/policy"
@@ -301,8 +301,8 @@ func (b *MapResponseBuilder) buildTailPeers(peers views.Slice[types.NodeView]) (
 	}
 
 	// Peers is always returned sorted by Node.ID.
-	sort.SliceStable(tailPeers, func(x, y int) bool {
-		return tailPeers[x].ID < tailPeers[y].ID
+	slices.SortStableFunc(tailPeers, func(a, b *tailcfg.Node) int {
+		return cmp.Compare(a.ID, b.ID)
 	})
 
 	return tailPeers, nil

hscontrol/mapper/node_conn.go

@@ -3,6 +3,7 @@ package mapper
 import (
 	"errors"
 	"fmt"
+	"slices"
 	"strconv"
 	"sync"
 	"sync/atomic"
@@ -142,9 +143,7 @@ func (mc *multiChannelNodeConn) stopConnection(conn *connectionEntry) {
 // Caller must hold mc.mutex.
 func (mc *multiChannelNodeConn) removeConnectionAtIndexLocked(i int, stopConnection bool) *connectionEntry {
 	conn := mc.connections[i]
-	copy(mc.connections[i:], mc.connections[i+1:])
-	mc.connections[len(mc.connections)-1] = nil // release pointer for GC
-	mc.connections = mc.connections[:len(mc.connections)-1]
+	mc.connections = slices.Delete(mc.connections, i, i+1)
 
 	if stopConnection {
 		mc.stopConnection(conn)
@@ -353,32 +352,22 @@ func (mc *multiChannelNodeConn) send(data *tailcfg.MapResponse) error {
 		// Remove by pointer identity: only remove entries that still exist
 		// in the current connections slice and match a failed pointer.
 		// New connections added since the snapshot are not affected.
-		failedSet := make(map[*connectionEntry]struct{}, len(failed))
-		for _, f := range failed {
-			failedSet[f] = struct{}{}
-		}
-
-		clean := mc.connections[:0]
-		for _, conn := range mc.connections {
-			if _, isFailed := failedSet[conn]; !isFailed {
-				clean = append(clean, conn)
-			} else {
-				mc.log.Debug().
-					Str(zf.ConnID, conn.id).
-					Msg("send: removing failed connection")
-				// Tear down the owning session so the old serveLongPoll
-				// goroutine exits instead of lingering as a stale session.
-				mc.stopConnection(conn)
+		// DeleteFunc preserves order and zeroes trailing slots so removed
+		// *connectionEntry values are not retained by the backing array.
+		mc.connections = slices.DeleteFunc(mc.connections, func(conn *connectionEntry) bool {
+			if !slices.Contains(failed, conn) {
+				return false
 			}
-		}
 
-		// Nil out trailing slots so removed *connectionEntry values
-		// are not retained by the backing array.
-		for i := len(clean); i < len(mc.connections); i++ {
-			mc.connections[i] = nil
-		}
+			mc.log.Debug().
+				Str(zf.ConnID, conn.id).
+				Msg("send: removing failed connection")
+			// Tear down the owning session so the old serveLongPoll
+			// goroutine exits instead of lingering as a stale session.
+			mc.stopConnection(conn)
 
-		mc.connections = clean
+			return true
+		})
 		mc.mutex.Unlock()
 	}
 

hscontrol/policy/policy.go

@@ -8,7 +8,6 @@ import (
 	"github.com/juanfont/headscale/hscontrol/types"
 	"github.com/juanfont/headscale/hscontrol/util"
 	"github.com/rs/zerolog/log"
-	"github.com/samber/lo"
 	"tailscale.com/types/views"
 )
 
@@ -66,8 +65,7 @@ func ApproveRoutesWithPolicy(pm PolicyManager, nv types.NodeView, currentApprove
 	}
 
 	// Start with ALL currently approved routes - we never remove approved routes
-	newApproved := make([]netip.Prefix, len(currentApproved))
-	copy(newApproved, currentApproved)
+	newApproved := slices.Clone(currentApproved)
 
 	// Then, check for new routes that can be auto-approved
 	for _, route := range announcedRoutes {
@@ -86,13 +84,12 @@ func ApproveRoutesWithPolicy(pm PolicyManager, nv types.NodeView, currentApprove
 	// Sort and deduplicate
 	slices.SortFunc(newApproved, netip.Prefix.Compare)
 	newApproved = slices.Compact(newApproved)
-	newApproved = lo.Filter(newApproved, func(route netip.Prefix, index int) bool {
-		return route.IsValid()
+	newApproved = slices.DeleteFunc(newApproved, func(route netip.Prefix) bool {
+		return !route.IsValid()
 	})
 
 	// Sort the current approved for comparison
-	sortedCurrent := make([]netip.Prefix, len(currentApproved))
-	copy(sortedCurrent, currentApproved)
+	sortedCurrent := slices.Clone(currentApproved)
 	slices.SortFunc(sortedCurrent, netip.Prefix.Compare)
 
 	// Only update if the routes actually changed

hscontrol/policy/v2/policy.go

@@ -1455,20 +1455,9 @@ func (pm *PolicyManager) invalidateAutogroupSelfCache(oldNodes, newNodes views.S
 				affectedUsers[newNode.TypedUserID()] = struct{}{}
 			}
 
-			// Check if IPs changed (simple check - could be more sophisticated)
-			oldIPs := oldNode.IPs()
-
-			newIPs := newNode.IPs()
-			if len(oldIPs) != len(newIPs) {
+			// Check if IPs changed.
+			if !slices.Equal(oldNode.IPs(), newNode.IPs()) {
 				affectedUsers[newNode.TypedUserID()] = struct{}{}
-			} else {
-				// Check if any IPs are different
-				for i, oldIP := range oldIPs {
-					if i >= len(newIPs) || oldIP != newIPs[i] {
-						affectedUsers[newNode.TypedUserID()] = struct{}{}
-						break
-					}
-				}
 			}
 		}
 	}

hscontrol/policy/v2/sshtest.go

@@ -2,6 +2,7 @@ package v2
 
 import (
 	"fmt"
+	"maps"
 	"net/netip"
 	"slices"
 	"strings"
@@ -92,14 +93,7 @@ func (r SSHPolicyTestResults) Errors() string {
 }
 
 func sortedUsers(m map[string][]string) []string {
-	keys := make([]string, 0, len(m))
-	for k := range m {
-		keys = append(keys, k)
-	}
-
-	slices.Sort(keys)
-
-	return keys
+	return slices.Sorted(maps.Keys(m))
 }
 
 // displayUser shows an empty username as `""` rather than blank.
@@ -394,10 +388,7 @@ func resolveSSHTestSource(
 		return nil, 0, nil
 	}
 
-	out := make([]netip.Addr, 0)
-	for a := range addrs.Iter() {
-		out = append(out, a)
-	}
+	out := slices.Collect(addrs.Iter())
 
 	var userID uint
 

hscontrol/realip.go

@@ -5,6 +5,7 @@ import (
 	"net"
 	"net/http"
 	"net/netip"
+	"slices"
 
 	realclientip "github.com/realclientip/realclientip-go"
 )
@@ -77,13 +78,9 @@ func peerTrusted(remoteAddr string, trusted []netip.Prefix) bool {
 		return false
 	}
 
-	for _, p := range trusted {
-		if p.Contains(addr) {
-			return true
-		}
-	}
-
-	return false
+	return slices.ContainsFunc(trusted, func(p netip.Prefix) bool {
+		return p.Contains(addr)
+	})
 }
 
 func parsePeerAddr(remoteAddr string) (netip.Addr, bool) {

hscontrol/types/change/change.go

@@ -213,13 +213,7 @@ func (r Change) ShouldSendToNode(nodeID types.NodeID) bool {
 
 // HasFull returns true if any response in the slice is a full update ([Change.IsFull]).
 func HasFull(rs []Change) bool {
-	for _, r := range rs {
-		if r.IsFull() {
-			return true
-		}
-	}
-
-	return false
+	return slices.ContainsFunc(rs, Change.IsFull)
 }
 
 // SplitTargetedAndBroadcast separates responses into targeted (to specific node) and broadcast.

hscontrol/types/node.go

@@ -243,13 +243,7 @@ func (node *Node) IPs() []netip.Addr {
 
 // HasIP reports if a node has a given IP address.
 func (node *Node) HasIP(i netip.Addr) bool {
-	for _, ip := range node.IPs() {
-		if ip.Compare(i) == 0 {
-			return true
-		}
-	}
-
-	return false
+	return slices.Contains(node.IPs(), i)
 }
 
 // IsTagged reports if a device is tagged and therefore should not be treated

hscontrol/util/prompt.go

@@ -3,6 +3,7 @@ package util
 import (
 	"fmt"
 	"os"
+	"slices"
 	"strings"
 )
 
@@ -18,10 +19,6 @@ func YesNo(msg string) bool {
 	_, _ = fmt.Scanln(&resp)
 
 	resp = strings.ToLower(resp)
-	switch resp {
-	case "y", "yes", "sure":
-		return true
-	}
 
-	return false
+	return slices.Contains([]string{"y", "yes", "sure"}, resp)
 }

integration/hsic/hsic.go

@@ -18,7 +18,7 @@ import (
 	"os"
 	"path"
 	"path/filepath"
-	"sort"
+	"slices"
 	"strconv"
 	"strings"
 	"time"
@@ -1295,8 +1295,8 @@ func (t *HeadscaleInContainer) ListNodes(
 		}
 	}
 
-	sort.Slice(ret, func(i, j int) bool {
-		return cmp.Compare(ret[i].GetId(), ret[j].GetId()) == -1
+	slices.SortFunc(ret, func(a, b *v1.Node) int {
+		return cmp.Compare(a.GetId(), b.GetId())
 	})
 
 	return ret, nil