modernize: various cleanups

cli-plugins/manager/candidate_test.go

@@ -151,7 +151,7 @@ func TestValidateCandidate(t *testing.T) {
 				assert.ErrorContains(t, err, tc.err)
 			case tc.invalid != "":
 				assert.NilError(t, err)
-				assert.Assert(t, is.ErrorType(p.Err, reflect.TypeOf(&pluginError{})))
+				assert.Assert(t, is.ErrorType(p.Err, reflect.TypeFor[*pluginError]()))
 				assert.ErrorContains(t, p.Err, tc.invalid)
 			default:
 				assert.NilError(t, err)

cli-plugins/manager/hooks.go

@@ -1,3 +1,6 @@
+// FIXME(thaJeztah): remove once we are a module; the go:build directive prevents go from downgrading language version to go1.16:
+//go:build go1.24
+
 package manager
 
 import (
@@ -141,8 +144,7 @@ func pluginMatch(pluginCfg map[string]string, subCmd string) (string, bool) {
 		return "", false
 	}
 
-	commands := strings.Split(configuredPluginHooks, ",")
-	for _, hookCmd := range commands {
+	for hookCmd := range strings.SplitSeq(configuredPluginHooks, ",") {
 		if hookMatch(hookCmd, subCmd) {
 			return hookCmd, true
 		}

cli/command/container/opts.go

@@ -902,7 +902,7 @@ func convertToStandardNotation(ports []string) ([]string, error) {
 	for _, publish := range ports {
 		if strings.Contains(publish, "=") {
 			params := map[string]string{"protocol": "tcp"}
-			for _, param := range strings.Split(publish, ",") {
+			for param := range strings.SplitSeq(publish, ",") {
 				k, v, ok := strings.Cut(param, "=")
 				if !ok || k == "" {
 					return optsList, fmt.Errorf("invalid publish opts format (should be name=value but got '%s')", param)

cli/command/container/run_test.go

@@ -247,7 +247,7 @@ func TestRunPullTermination(t *testing.T) {
 			go func() {
 				id := test.RandomID()[:12] // short-ID
 				progressOutput := streamformatter.NewJSONProgressOutput(server, true)
-				for i := 0; i < 100; i++ {
+				for i := range 100 {
 					select {
 					case <-ctx.Done():
 						assert.NilError(t, server.Close(), "failed to close imageCreateFunc server")

cli/command/container/signals_test.go

@@ -11,8 +11,7 @@ import (
 )
 
 func TestForwardSignals(t *testing.T) {
-	ctx, cancel := context.WithCancel(context.Background())
-	defer cancel()
+	ctx := t.Context()
 
 	called := make(chan struct{})
 	apiClient := &fakeClient{containerKillFunc: func(ctx context.Context, container string, options client.ContainerKillOptions) (client.ContainerKillResult, error) {

cli/command/container/stats.go

@@ -1,3 +1,6 @@
+// FIXME(thaJeztah): remove once we are a module; the go:build directive prevents go from downgrading language version to go1.16:
+//go:build go1.24
+
 package container
 
 import (
@@ -337,7 +340,7 @@ func RunStats(ctx context.Context, dockerCLI command.Cli, options *StatsOptions)
 				return err
 			}
 
-			for _, line := range strings.Split(statsTextBuffer.String(), "\n") {
+			for line := range strings.SplitSeq(statsTextBuffer.String(), "\n") {
 				// In case the new text is shorter than the one we are writing over,
 				// we'll append the "erase line" escape sequence to clear the remaining text.
 				_, _ = fmt.Fprintln(&statsTextBuffer, line, "\033[K")

cli/command/container/tty.go

@@ -60,7 +60,7 @@ func initTtySize(ctx context.Context, cli command.Cli, id string, isExec bool, r
 	if err := rTTYfunc(ctx, cli, id, isExec); err != nil {
 		go func() {
 			var err error
-			for retry := 0; retry < 10; retry++ {
+			for retry := range 10 {
 				time.Sleep(time.Duration(retry+1) * 10 * time.Millisecond)
 				if err = rTTYfunc(ctx, cli, id, isExec); err == nil {
 					break

cli/command/context.go

@@ -6,6 +6,7 @@ package command
 import (
 	"encoding/json"
 	"errors"
+	"maps"
 
 	"github.com/docker/cli/cli/context/store"
 )
@@ -23,9 +24,7 @@ func (dc DockerContext) MarshalJSON() ([]byte, error) {
 		s["Description"] = dc.Description
 	}
 	if dc.AdditionalFields != nil {
-		for k, v := range dc.AdditionalFields {
-			s[k] = v
-		}
+		maps.Copy(s, dc.AdditionalFields)
 	}
 	return json.Marshal(s)
 }

cli/command/formatter/tabwriter/tabwriter_test.go

@@ -25,7 +25,7 @@ func (b *buffer) Write(buf []byte) (written int, err error) {
 	m := len(buf)
 	if n+m <= cap(b.a) {
 		b.a = b.a[0 : n+m]
-		for i := 0; i < m; i++ {
+		for i := range m {
 			b.a[n+i] = buf[i]
 		}
 	} else {
@@ -669,7 +669,7 @@ func BenchmarkTable(b *testing.B) {
 					for i := 0; i < b.N; i++ {
 						w := NewWriter(io.Discard, 4, 4, 1, ' ', 0) // no particular reason for these settings
 						// Write the line h times.
-						for j := 0; j < h; j++ {
+						for range h {
 							w.Write(line)
 						}
 						w.Flush()
@@ -681,7 +681,7 @@ func BenchmarkTable(b *testing.B) {
 					w := NewWriter(io.Discard, 4, 4, 1, ' ', 0) // no particular reason for these settings
 					for i := 0; i < b.N; i++ {
 						// Write the line h times.
-						for j := 0; j < h; j++ {
+						for range h {
 							w.Write(line)
 						}
 						w.Flush()
@@ -701,7 +701,7 @@ func BenchmarkPyramid(b *testing.B) {
 			for i := 0; i < b.N; i++ {
 				w := NewWriter(io.Discard, 4, 4, 1, ' ', 0) // no particular reason for these settings
 				// Write increasing prefixes of that line.
-				for j := 0; j < x; j++ {
+				for j := range x {
 					w.Write(line[:j*2])
 					w.Write([]byte{'\n'})
 				}
@@ -723,7 +723,7 @@ func BenchmarkRagged(b *testing.B) {
 			for i := 0; i < b.N; i++ {
 				w := NewWriter(io.Discard, 4, 4, 1, ' ', 0) // no particular reason for these settings
 				// Write the lines in turn h times.
-				for j := 0; j < h; j++ {
+				for j := range h {
 					w.Write(lines[j%len(lines)])
 					w.Write([]byte{'\n'})
 				}

cli/command/idresolver/idresolver_test.go

@@ -60,7 +60,7 @@ func TestResolveWithCache(t *testing.T) {
 	idResolver := New(apiClient, false)
 
 	ctx := context.Background()
-	for i := 0; i < 2; i++ {
+	for range 2 {
 		id, err := idResolver.Resolve(ctx, swarm.Node{}, "nodeID")
 		assert.NilError(t, err)
 		assert.Check(t, is.Equal("node-foo", id))

cli/command/image/tree.go

@@ -389,10 +389,7 @@ func generateLegend(out tui.Output, width uint) string {
 	}
 	legend += legendSb371.String()
 
-	r := int(width) - tui.Width(legend)
-	if r < 0 {
-		r = 0
-	}
+	r := max(int(width)-tui.Width(legend), 0)
 	legend = strings.Repeat(" ", r) + legend
 	return legend
 }

cli/command/manifest/annotate.go

@@ -1,9 +1,13 @@
+// FIXME(thaJeztah): remove once we are a module; the go:build directive prevents go from downgrading language version to go1.16:
+//go:build go1.24
+
 package manifest
 
 import (
 	"context"
 	"fmt"
 	"path/filepath"
+	"slices"
 
 	"github.com/containerd/errdefs"
 	"github.com/docker/cli/cli"
@@ -164,10 +168,8 @@ func runManifestAnnotate(dockerCLI command.Cli, opts annotateOptions) error {
 }
 
 func appendIfUnique(list []string, str string) []string {
-	for _, s := range list {
-		if s == str {
-			return list
-		}
+	if slices.Contains(list, str) {
+		return list
 	}
 	return append(list, str)
 }

cli/command/node/update.go

@@ -1,9 +1,13 @@
+// FIXME(thaJeztah): remove once we are a module; the go:build directive prevents go from downgrading language version to go1.16:
+//go:build go1.24
+
 package node
 
 import (
 	"context"
 	"errors"
 	"fmt"
+	"maps"
 
 	"github.com/docker/cli/cli"
 	"github.com/docker/cli/cli/command"
@@ -99,9 +103,7 @@ func mergeNodeUpdate(flags *pflag.FlagSet) func(*swarm.Node) error {
 		}
 		if flags.Changed(flagLabelAdd) {
 			labels := flags.Lookup(flagLabelAdd).Value.(*opts.ListOpts).GetSlice()
-			for k, v := range opts.ConvertKVStringsToMap(labels) {
-				spec.Annotations.Labels[k] = v
-			}
+			maps.Copy(spec.Annotations.Labels, opts.ConvertKVStringsToMap(labels))
 		}
 		if flags.Changed(flagLabelRemove) {
 			keys := flags.Lookup(flagLabelRemove).Value.(*opts.ListOpts).GetSlice()

cli/command/service/list_test.go

@@ -191,10 +191,7 @@ func generateServices(t *testing.T, opts clusterOpts) client.ServiceListResult {
 	t.Helper()
 
 	// Can't have more global tasks than nodes
-	globalTasks := opts.runningTasks
-	if globalTasks > opts.activeNodes {
-		globalTasks = opts.activeNodes
-	}
+	globalTasks := min(opts.runningTasks, opts.activeNodes)
 	return client.ServiceListResult{
 		Items: []swarm.Service{
 			*builders.Service(
@@ -279,7 +276,7 @@ func generateNodes(t *testing.T, activeNodes uint64) client.NodeListResult {
 	t.Helper()
 	nodes := client.NodeListResult{}
 	var i uint64
-	for i = 0; i < activeNodes; i++ {
+	for i = range activeNodes {
 		nodes.Items = append(nodes.Items, swarm.Node{
 			ID:     fmt.Sprintf("node-ready-%d", i),
 			Status: swarm.NodeStatus{State: swarm.NodeStateReady},

cli/command/service/progress/progress.go

@@ -662,10 +662,7 @@ func (u *replicatedJobProgressUpdater) writeOverallProgress(active, completed in
 	})
 
 	// actualDesired is the lesser of MaxConcurrent, or the remaining tasks
-	actualDesired := u.total - completed
-	if actualDesired > u.concurrent {
-		actualDesired = u.concurrent
-	}
+	actualDesired := min(u.total-completed, u.concurrent)
 
 	_ = u.progressOut.WriteProgress(progress.Progress{
 		ID: "active tasks",

cli/command/service/progress/progress_test.go

@@ -856,7 +856,7 @@ func TestGlobalJobProgressUpdaterLarge(t *testing.T) {
 	}
 
 	activeNodes := map[string]struct{}{}
-	for i := 0; i < 50; i++ {
+	for i := range 50 {
 		activeNodes[fmt.Sprintf("node%v", i)] = struct{}{}
 	}
 

cli/command/service/update.go

@@ -7,6 +7,7 @@ import (
 	"context"
 	"errors"
 	"fmt"
+	"maps"
 	"net/netip"
 	"slices"
 	"sort"
@@ -551,12 +552,7 @@ func updateStringToSlice(flags *pflag.FlagSet, flag string, field *[]string) {
 }
 
 func anyChanged(flags *pflag.FlagSet, fields ...string) bool {
-	for _, flag := range fields {
-		if flags.Changed(flag) {
-			return true
-		}
-	}
-	return false
+	return slices.ContainsFunc(fields, flags.Changed)
 }
 
 func addGenericResources(flags *pflag.FlagSet, spec *swarm.TaskSpec) error {
@@ -685,9 +681,7 @@ func updateContainerLabels(flags *pflag.FlagSet, field *map[string]string) {
 		}
 
 		values := flags.Lookup(flagContainerLabelAdd).Value.(*opts.ListOpts).GetSlice()
-		for key, value := range opts.ConvertKVStringsToMap(values) {
-			(*field)[key] = value
-		}
+		maps.Copy((*field), opts.ConvertKVStringsToMap(values))
 	}
 }
 
@@ -704,9 +698,7 @@ func updateLabels(flags *pflag.FlagSet, field *map[string]string) {
 		}
 
 		values := flags.Lookup(flagLabelAdd).Value.(*opts.ListOpts).GetSlice()
-		for key, value := range opts.ConvertKVStringsToMap(values) {
-			(*field)[key] = value
-		}
+		maps.Copy((*field), opts.ConvertKVStringsToMap(values))
 	}
 }
 
@@ -723,9 +715,7 @@ func updateSysCtls(flags *pflag.FlagSet, field *map[string]string) {
 		}
 
 		values := flags.Lookup(flagSysCtlAdd).Value.(*opts.ListOpts).GetSlice()
-		for key, value := range opts.ConvertKVStringsToMap(values) {
-			(*field)[key] = value
-		}
+		maps.Copy((*field), opts.ConvertKVStringsToMap(values))
 	}
 }
 

cli/command/telemetry_utils.go

@@ -155,11 +155,11 @@ func (e statusError) Error() string {
 // Note: The root command's name is excluded. If cmd is the root cmd, return ""
 func getCommandName(cmd *cobra.Command) string {
 	fullCmdName := getFullCommandName(cmd)
-	i := strings.Index(fullCmdName, " ")
-	if i == -1 {
+	_, after, ok := strings.Cut(fullCmdName, " ")
+	if !ok {
 		return ""
 	}
-	return fullCmdName[i+1:]
+	return after
 }
 
 // getFullCommandName gets the full cobra command name in the format

cli/command/volume/create.go

@@ -1,3 +1,6 @@
+// FIXME(thaJeztah): remove once we are a module; the go:build directive prevents go from downgrading language version to go1.16:
+//go:build go1.24
+
 package volume
 
 import (
@@ -166,7 +169,7 @@ func runCreate(ctx context.Context, dockerCli command.Cli, options createOptions
 			// each topology takes the form segment=value,segment=value
 			// comma-separated list of equal separated maps
 			segments := map[string]string{}
-			for _, segment := range strings.Split(top, ",") {
+			for segment := range strings.SplitSeq(top, ",") {
 				// TODO(dperny): validate topology syntax
 				k, v, _ := strings.Cut(segment, "=")
 				segments[k] = v
@@ -181,7 +184,7 @@ func runCreate(ctx context.Context, dockerCli command.Cli, options createOptions
 			// each topology takes the form segment=value,segment=value
 			// comma-separated list of equal separated maps
 			segments := map[string]string{}
-			for _, segment := range strings.Split(top, ",") {
+			for segment := range strings.SplitSeq(top, ",") {
 				// TODO(dperny): validate topology syntax
 				k, v, _ := strings.Cut(segment, "=")
 				segments[k] = v

cli/compose/loader/loader.go

@@ -6,6 +6,7 @@ package loader
 import (
 	"errors"
 	"fmt"
+	"maps"
 	"path"
 	"path/filepath"
 	"reflect"
@@ -249,9 +250,7 @@ func GetDeprecatedProperties(configDicts ...map[string]any) map[string]string {
 
 	for _, configDict := range configDicts {
 		deprecatedProperties := getProperties(getServices(configDict), types.DeprecatedProperties)
-		for key, value := range deprecatedProperties {
-			deprecated[key] = value
-		}
+		maps.Copy(deprecated, deprecatedProperties)
 	}
 
 	return deprecated

cli/compose/loader/merge_test.go

@@ -1153,7 +1153,7 @@ func TestLoadMultipleServiceVolumes(t *testing.T) {
 func TestMergeUlimitsConfig(t *testing.T) {
 	specials := &specials{
 		m: map[reflect.Type]func(dst, src reflect.Value) error{
-			reflect.TypeOf(&types.UlimitsConfig{}): mergeUlimitsConfig,
+			reflect.TypeFor[*types.UlimitsConfig](): mergeUlimitsConfig,
 		},
 	}
 	base := map[string]*types.UlimitsConfig{
@@ -1189,7 +1189,7 @@ func TestMergeUlimitsConfig(t *testing.T) {
 func TestMergeServiceNetworkConfig(t *testing.T) {
 	specials := &specials{
 		m: map[reflect.Type]func(dst, src reflect.Value) error{
-			reflect.TypeOf(&types.ServiceNetworkConfig{}): mergeServiceNetworkConfig,
+			reflect.TypeFor[*types.ServiceNetworkConfig](): mergeServiceNetworkConfig,
 		},
 	}
 	base := map[string]*types.ServiceNetworkConfig{