refactor: remove unneeded in Go 1.22 loop var copy (#4856)

The PR cleans up unnecessary loop variable copying and enables the
[`copyloopvar`](https://golangci-lint.run/usage/linters/#copyloopvar)
linter for detecting this redundant variable copying.

#### Additional notes

After the project upgraded to Go version 1.22 in #4779, copying
variables inside a `for` loop became unnecessary. See this [blog
post](https://go.dev/blog/loopvar-preview) for a detailed explanation.

The `copyloopvar` linter is only available from `golangci-lint` v1.57
onwards, so we also need to update this tool.

.github/workflows/lint.yml

@@ -23,7 +23,7 @@ jobs:
           go-version: stable
           cache: false
       - name: golangci-lint
-        uses: golangci/golangci-lint-action@a4f60bb28d35aeee14e6880718e0c85ff1882e64 # v3
+        uses: golangci/golangci-lint-action@a4f60bb28d35aeee14e6880718e0c85ff1882e64 # v6.0.1
         with:
           args: --timeout=5m
-          version: v1.56.2
+          version: v1.58.1

.golangci.yaml

@@ -3,6 +3,7 @@ run:
   timeout: 5m
 linters:
   enable:
+    - copyloopvar
     - thelper
     - gofumpt
     - bodyclose

internal/artifact/artifact.go

@@ -483,7 +483,6 @@ func ByType(t Type) Filter {
 func ByFormats(formats ...string) Filter {
 	filters := make([]Filter, 0, len(formats))
 	for _, format := range formats {
-		format := format
 		filters = append(filters, func(a *Artifact) bool {
 			return a.Format() == format
 		})
@@ -495,7 +494,6 @@ func ByFormats(formats ...string) Filter {
 func ByIDs(ids ...string) Filter {
 	filters := make([]Filter, 0, len(ids))
 	for _, id := range ids {
-		id := id
 		filters = append(filters, func(a *Artifact) bool {
 			// checksum and source archive are always for all artifacts, so return always true.
 			return a.Type == Checksum ||
@@ -512,7 +510,6 @@ func ByIDs(ids ...string) Filter {
 func ByExt(exts ...string) Filter {
 	filters := make([]Filter, 0, len(exts))
 	for _, ext := range exts {
-		ext := ext
 		filters = append(filters, func(a *Artifact) bool {
 			return ExtraOr(*a, ExtraExt, "") == ext
 		})

internal/artifact/artifact_test.go

@@ -44,7 +44,6 @@ func TestAdd(t *testing.T) {
 			Type: Checksum,
 		},
 	} {
-		a := a
 		g.Go(func() error {
 			artifacts.Add(a)
 			return nil

internal/exec/exec.go

@@ -70,7 +70,6 @@ func executePublisher(ctx *context.Context, publisher config.Publisher) error {
 
 	g := semerrgroup.New(ctx.Parallelism)
 	for _, artifact := range artifacts {
-		artifact := artifact
 		g.Go(func() error {
 			c, err := resolveCommand(ctx, publisher, artifact)
 			if err != nil {

internal/http/http.go

@@ -156,7 +156,6 @@ type ResponseChecker func(*h.Response) error
 func Upload(ctx *context.Context, uploads []config.Upload, kind string, check ResponseChecker) error {
 	// Handle every configured upload
 	for _, upload := range uploads {
-		upload := upload
 		filters := []artifact.Filter{}
 		if upload.Checksum {
 			filters = append(filters, artifact.ByType(artifact.Checksum))
@@ -206,7 +205,6 @@ func uploadWithFilter(ctx *context.Context, upload *config.Upload, filter artifa
 	log.Debugf("will upload %d artifacts", len(artifacts))
 	g := semerrgroup.New(ctx.Parallelism)
 	for _, artifact := range artifacts {
-		artifact := artifact
 		g.Go(func() error {
 			return uploadAsset(ctx, upload, artifact, kind, check)
 		})

internal/pipe/archive/archive.go

@@ -91,7 +91,6 @@ func (Pipe) Default(ctx *context.Context) error {
 func (Pipe) Run(ctx *context.Context) error {
 	g := semerrgroup.New(ctx.Parallelism)
 	for i, archive := range ctx.Config.Archives {
-		archive := archive
 		if archive.Meta {
 			g.Go(func() error {
 				return createMeta(ctx, archive)
@@ -115,7 +114,6 @@ func (Pipe) Run(ctx *context.Context) error {
 		}
 		for group, artifacts := range artifacts {
 			log.Debugf("group %s has %d binaries", group, len(artifacts))
-			artifacts := artifacts
 			format := packageFormat(archive, artifacts[0].Goos)
 			switch format {
 			case "none":

internal/pipe/artifactory/artifactory.go

@@ -36,7 +36,6 @@ func (Pipe) Publish(ctx *context.Context) error {
 	// Check requirements for every instance we have configured.
 	// If not fulfilled, we can skip this pipeline
 	for _, instance := range ctx.Config.Artifactories {
-		instance := instance
 		if skip := http.CheckConfig(ctx, &instance, "artifactory"); skip != nil {
 			return pipe.Skip(skip.Error())
 		}

internal/pipe/blob/blob.go

@@ -57,7 +57,6 @@ func (Pipe) Publish(ctx *context.Context) error {
 	g := semerrgroup.New(ctx.Parallelism)
 	skips := pipe.SkipMemento{}
 	for _, conf := range ctx.Config.Blobs {
-		conf := conf
 		g.Go(func() error {
 			b, err := tmpl.New(ctx).Bool(conf.Disable)
 			if err != nil {

internal/pipe/blob/upload.go

@@ -137,7 +137,6 @@ func doUpload(ctx *context.Context, conf config.Blob) error {
 
 	g := semerrgroup.New(ctx.Parallelism)
 	for _, artifact := range ctx.Artifacts.Filter(filter).List() {
-		artifact := artifact
 		g.Go(func() error {
 			// TODO: replace this with ?prefix=folder on the bucket url
 			dataFile := artifact.Path
@@ -152,8 +151,6 @@ func doUpload(ctx *context.Context, conf config.Blob) error {
 		return err
 	}
 	for name, fullpath := range files {
-		name := name
-		fullpath := fullpath
 		g.Go(func() error {
 			uploadFile := path.Join(dir, name)
 			return uploadData(ctx, conf, up, fullpath, uploadFile, bucketURL)

internal/pipe/build/build.go

@@ -89,8 +89,6 @@ func buildWithDefaults(ctx *context.Context, build config.Build) (config.Build,
 
 func runPipeOnBuild(ctx *context.Context, g semerrgroup.Group, build config.Build) {
 	for _, target := range filter(ctx, build.Targets) {
-		target := target
-		build := build
 		g.Go(func() error {
 			opts, err := buildOptionsForTarget(ctx, build, target)
 			if err != nil {

internal/pipe/checksums/checksums.go

@@ -141,8 +141,6 @@ func refreshAll(ctx *context.Context, filepath string) error {
 	g := semerrgroup.New(ctx.Parallelism)
 	sumLines := make([]string, len(artifactList))
 	for i, artifact := range artifactList {
-		i := i
-		artifact := artifact
 		g.Go(func() error {
 			sumLine, err := checksums(ctx.Config.Checksum.Algorithm, artifact)
 			if err != nil {

internal/pipe/docker/docker.go

@@ -118,8 +118,6 @@ func (Pipe) Publish(ctx *context.Context) error {
 func (Pipe) Run(ctx *context.Context) error {
 	g := semerrgroup.NewSkipAware(semerrgroup.New(ctx.Parallelism))
 	for i, docker := range ctx.Config.Dockers {
-		i := i
-		docker := docker
 		g.Go(func() error {
 			log := log.WithField("index", i)
 			log.Debug("looking for artifacts matching")

internal/pipe/docker/docker_test.go

@@ -1398,7 +1398,6 @@ func TestWithDigest(t *testing.T) {
 	})
 
 	for _, use := range []string{useDocker, useBuildx} {
-		use := use
 		t.Run(use, func(t *testing.T) {
 			t.Run("good", func(t *testing.T) {
 				require.Equal(t, "localhost:5050/owner/img:t1@sha256:d1", withDigest(use, "localhost:5050/owner/img:t1", artifacts.List()))

internal/pipe/docker/manifest.go

@@ -60,7 +60,6 @@ func (ManifestPipe) Default(ctx *context.Context) error {
 func (ManifestPipe) Publish(ctx *context.Context) error {
 	g := semerrgroup.NewSkipAware(semerrgroup.New(1))
 	for _, manifest := range ctx.Config.DockerManifests {
-		manifest := manifest
 		g.Go(func() error {
 			skip, err := tmpl.New(ctx).Apply(manifest.SkipPush)
 			if err != nil {

internal/pipe/ko/ko_test.go

@@ -193,7 +193,6 @@ func TestPublishPipeSuccess(t *testing.T) {
 	repository := fmt.Sprintf("%sgoreleasertest/testapp", registry)
 
 	for _, table := range table {
-		table := table
 		t.Run(table.Name, func(t *testing.T) {
 			if len(table.Tags) == 0 {
 				table.Tags = []string{table.Name}

internal/pipe/nfpm/nfpm.go

@@ -118,8 +118,6 @@ func doRun(ctx *context.Context, fpm config.NFPM) error {
 	g := semerrgroup.New(ctx.Parallelism)
 	for _, format := range fpm.Formats {
 		for _, artifacts := range linuxBinaries {
-			format := format
-			artifacts := artifacts
 			g.Go(func() error {
 				return create(ctx, fpm, format, artifacts)
 			})

internal/pipe/release/body_test.go

@@ -56,8 +56,6 @@ func TestDescribeBodyMultipleChecksums(t *testing.T) {
 		"foo.zip": "271a74b75a12f6c3affc88df101f9ef29af79717b1b2f4bdd5964aacf65bcf40",
 	}
 	for name, check := range checksums {
-		name := name
-		check := check
 		checksumPath := filepath.Join(t.TempDir(), name+".sha256")
 		ctx.Artifacts.Add(&artifact.Artifact{
 			Name: name + ".sha256",

internal/pipe/release/release.go

@@ -175,7 +175,6 @@ func doPublish(ctx *context.Context, client client.Client) error {
 
 	g := semerrgroup.New(ctx.Parallelism)
 	for _, artifact := range ctx.Artifacts.Filter(filters).List() {
-		artifact := artifact
 		g.Go(func() error {
 			return upload(ctx, client, releaseID, artifact)
 		})

internal/pipe/scoop/scoop_test.go

@@ -720,7 +720,6 @@ func Test_doRun(t *testing.T) {
 			ctx := tt.args.ctx
 			ctx.Config.Dist = t.TempDir()
 			for _, a := range tt.artifacts {
-				a := a
 				a.Type = artifact.UploadableArchive
 				ctx.Artifacts.Add(&a)
 			}

internal/pipe/snapcraft/snapcraft.go

@@ -193,7 +193,6 @@ func doRun(ctx *context.Context, snap config.Snapcraft) error {
 			log.WithField("arch", arch).Warn("ignored unsupported arch")
 			continue
 		}
-		binaries := binaries
 		g.Go(func() error {
 			return create(ctx, snap, arch, binaries)
 		})

internal/pipe/universalbinary/universalbinary.go

@@ -53,7 +53,6 @@ func (Pipe) Default(ctx *context.Context) error {
 func (Pipe) Run(ctx *context.Context) error {
 	g := semerrgroup.NewSkipAware(semerrgroup.New(ctx.Parallelism))
 	for _, unibin := range ctx.Config.UniversalBinaries {
-		unibin := unibin
 		g.Go(func() error {
 			opts := build.Options{
 				Target: "darwin_all",

internal/pipe/upload/upload.go

@@ -27,7 +27,6 @@ func (Pipe) Publish(ctx *context.Context) error {
 	// Check requirements for every instance we have configured.
 	// If not fulfilled, we can skip this pipeline
 	for _, instance := range ctx.Config.Uploads {
-		instance := instance
 		if skip := http.CheckConfig(ctx, &instance, "upload"); skip != nil {
 			return pipe.Skip(skip.Error())
 		}

internal/pipe/upx/upx.go

@@ -32,7 +32,6 @@ func (Pipe) Skip(ctx *context.Context) bool { return len(ctx.Config.UPXs) == 0 }
 func (Pipe) Run(ctx *context.Context) error {
 	g := semerrgroup.NewSkipAware(semerrgroup.New(ctx.Parallelism))
 	for _, upx := range ctx.Config.UPXs {
-		upx := upx
 		enabled, err := tmpl.New(ctx).Bool(upx.Enabled)
 		if err != nil {
 			return err
@@ -44,7 +43,6 @@ func (Pipe) Run(ctx *context.Context) error {
 			return pipe.Skipf("%s not found in PATH", upx.Binary)
 		}
 		for _, bin := range findBinaries(ctx, upx) {
-			bin := bin
 			g.Go(func() error {
 				sizeBefore := sizeOf(bin.Path)
 				args := []string{

internal/semerrgroup/sem_test.go

@@ -37,7 +37,6 @@ func TestSemaphoreOrder(t *testing.T) {
 	g := New(1)
 	output := []int{}
 	for i := 0; i < num; i++ {
-		i := i
 		g.Go(func() error {
 			output = append(output, i)
 			return nil
@@ -54,7 +53,6 @@ func TestSemaphoreError(t *testing.T) {
 			var lock sync.Mutex
 			output := []int{}
 			for i := 0; i < 10; i++ {
-				i := i
 				g.Go(func() error {
 					lock.Lock()
 					defer lock.Unlock()
@@ -90,7 +88,6 @@ func TestSemaphoreSkipAwareSingleError(t *testing.T) {
 		t.Run(fmt.Sprintf("limit-%d", i), func(t *testing.T) {
 			g := NewSkipAware(New(i))
 			for i := 0; i < 10; i++ {
-				i := i
 				g.Go(func() error {
 					time.Sleep(10 * time.Millisecond)
 					if i == 5 {

internal/tmpl/tmpl_test.go

@@ -104,8 +104,6 @@ func TestWithArtifact(t *testing.T) {
 		// maps
 		"123": `{{ $m := map "a" "1" "b" "2" }}{{ index $m "a" }}{{ indexOrDefault $m "b" "10" }}{{ indexOrDefault $m "c" "3" }}{{ index $m "z" }}`,
 	} {
-		tmpl := tmpl
-		expect := expect
 		t.Run(expect, func(t *testing.T) {
 			t.Parallel()
 			result, err := New(ctx).WithArtifact(

main_test.go

@@ -36,7 +36,6 @@ func TestVersion(t *testing.T) {
 			builtBy: "me",
 		},
 	} {
-		tt := tt
 		t.Run(name, func(t *testing.T) {
 			v := buildVersion(tt.version, tt.commit, tt.date, tt.builtBy, tt.treeState)
 			v.GoVersion = goVersion

pkg/archive/archive_test.go

@@ -19,7 +19,6 @@ func TestArchive(t *testing.T) {
 	require.NoError(t, os.Mkdir(folder+"/folder-inside", 0o755))
 
 	for _, format := range []string{"tar.gz", "zip", "gz", "tar.xz", "tar", "tgz", "txz", "tar.zst"} {
-		format := format
 		t.Run(format, func(t *testing.T) {
 			f1, err := os.Create(filepath.Join(t.TempDir(), "1.tar"))
 			require.NoError(t, err)