refactor: add function to apply template multiple times (#4158)

If applied, this commit simplifies the code required to support
templated fields in configuration files. This should make it easier to
add more templated fields in the future.

As [discussed first on
Discord](https://discord.com/channels/890434333251362866/1032457293687685191/1124033219747127316).

internal/archivefiles/archivefiles.go

@@ -70,20 +70,15 @@ func Eval(template *tmpl.Template, files []config.File) ([]config.File, error) {
 }
 
 func tmplInfo(template *tmpl.Template, info *config.FileInfo) error {
-	var err error
-	info.Owner, err = template.Apply(info.Owner)
-	if err != nil {
-		return fmt.Errorf("failed to apply template %s: %w", info.Owner, err)
-	}
-	info.Group, err = template.Apply(info.Group)
-	if err != nil {
-		return fmt.Errorf("failed to apply template %s: %w", info.Group, err)
-	}
-	info.MTime, err = template.Apply(info.MTime)
-	if err != nil {
-		return fmt.Errorf("failed to apply template %s: %w", info.MTime, err)
+	if err := template.ApplyAll(
+		&info.Owner,
+		&info.Group,
+		&info.MTime,
+	); err != nil {
+		return err
 	}
 	if info.MTime != "" {
+		var err error
 		info.ParsedMTime, err = time.Parse(time.RFC3339Nano, info.MTime)
 		if err != nil {
 			return fmt.Errorf("failed to parse %s: %w", info.MTime, err)

internal/pipe/chocolatey/chocolatey.go

@@ -218,18 +218,12 @@ func doPush(ctx *context.Context, art *artifact.Artifact) error {
 
 func buildNuspec(ctx *context.Context, choco config.Chocolatey) ([]byte, error) {
 	tpl := tmpl.New(ctx)
-	summary, err := tpl.Apply(choco.Summary)
-	if err != nil {
-		return nil, err
-	}
 
-	description, err := tpl.Apply(choco.Description)
-	if err != nil {
-		return nil, err
-	}
-
-	releaseNotes, err := tpl.Apply(choco.ReleaseNotes)
-	if err != nil {
+	if err := tpl.ApplyAll(
+		&choco.Summary,
+		&choco.Description,
+		&choco.ReleaseNotes,
+	); err != nil {
 		return nil, err
 	}
 
@@ -251,9 +245,9 @@ func buildNuspec(ctx *context.Context, choco config.Chocolatey) ([]byte, error)
 			DocsURL:                  choco.DocsURL,
 			BugTrackerURL:            choco.BugTrackerURL,
 			Tags:                     choco.Tags,
-			Summary:                  summary,
-			Description:              description,
-			ReleaseNotes:             releaseNotes,
+			Summary:                  choco.Summary,
+			Description:              choco.Description,
+			ReleaseNotes:             choco.ReleaseNotes,
 		},
 		Files: Files{File: []File{
 			{Source: "tools\\**", Target: "tools"},

internal/pipe/krew/krew.go

@@ -159,31 +159,17 @@ func doRun(ctx *context.Context, krew config.Krew, cl client.ReleaserURLTemplate
 
 func templateFields(ctx *context.Context, krew config.Krew) (config.Krew, error) {
 	t := tmpl.New(ctx)
-	var err error
-	krew.Name, err = t.Apply(krew.Name)
-	if err != nil {
+
+	if err := t.ApplyAll(
+		&krew.Name,
+		&krew.Homepage,
+		&krew.Description,
+		&krew.Caveats,
+		&krew.ShortDescription,
+	); err != nil {
 		return config.Krew{}, err
 	}
 
-	krew.Homepage, err = t.Apply(krew.Homepage)
-	if err != nil {
-		return config.Krew{}, err
-	}
-
-	krew.Description, err = t.Apply(krew.Description)
-	if err != nil {
-		return config.Krew{}, err
-	}
-
-	krew.Caveats, err = t.Apply(krew.Caveats)
-	if err != nil {
-		return config.Krew{}, err
-	}
-
-	krew.ShortDescription, err = t.Apply(krew.ShortDescription)
-	if err != nil {
-		return config.Krew{}, err
-	}
 	return krew, nil
 }
 

internal/pipe/krew/krew_test.go

@@ -183,7 +183,7 @@ func TestFullPipe(t *testing.T) {
 				ctx.Config.Krews[0].Repository.Name = "test"
 				ctx.Config.Krews[0].Description = "{{ .Asdsa }"
 			},
-			expectedRunError: `template: tmpl:1: unexpected "}" in operand`,
+			expectedRunError: `failed to apply template: {{ .Asdsa }: template: tmpl:1: unexpected "}" in operand`,
 		},
 		"invalid short desc": {
 			prepare: func(ctx *context.Context) {
@@ -191,7 +191,7 @@ func TestFullPipe(t *testing.T) {
 				ctx.Config.Krews[0].Repository.Name = "test"
 				ctx.Config.Krews[0].ShortDescription = "{{ .Asdsa }"
 			},
-			expectedRunError: `template: tmpl:1: unexpected "}" in operand`,
+			expectedRunError: `failed to apply template: {{ .Asdsa }: template: tmpl:1: unexpected "}" in operand`,
 		},
 		"invalid homepage": {
 			prepare: func(ctx *context.Context) {
@@ -199,7 +199,7 @@ func TestFullPipe(t *testing.T) {
 				ctx.Config.Krews[0].Repository.Name = "test"
 				ctx.Config.Krews[0].Homepage = "{{ .Asdsa }"
 			},
-			expectedRunError: `template: tmpl:1: unexpected "}" in operand`,
+			expectedRunError: `failed to apply template: {{ .Asdsa }: template: tmpl:1: unexpected "}" in operand`,
 		},
 		"invalid name": {
 			prepare: func(ctx *context.Context) {
@@ -207,7 +207,7 @@ func TestFullPipe(t *testing.T) {
 				ctx.Config.Krews[0].Repository.Name = "test"
 				ctx.Config.Krews[0].Name = "{{ .Asdsa }"
 			},
-			expectedRunError: `template: tmpl:1: unexpected "}" in operand`,
+			expectedRunError: `failed to apply template: {{ .Asdsa }: template: tmpl:1: unexpected "}" in operand`,
 		},
 		"invalid caveats": {
 			prepare: func(ctx *context.Context) {
@@ -215,7 +215,7 @@ func TestFullPipe(t *testing.T) {
 				ctx.Config.Krews[0].Repository.Name = "test"
 				ctx.Config.Krews[0].Caveats = "{{ .Asdsa }"
 			},
-			expectedRunError: `template: tmpl:1: unexpected "}" in operand`,
+			expectedRunError: `failed to apply template: {{ .Asdsa }: template: tmpl:1: unexpected "}" in operand`,
 		},
 		"no short desc": {
 			prepare: func(ctx *context.Context) {

internal/pipe/nfpm/nfpm.go

@@ -149,7 +149,6 @@ func create(ctx *context.Context, fpm config.NFPM, format string, binaries []*ar
 		}
 	}
 
-	bindDir := fpm.Bindir
 	if format == termuxFormat {
 		if !isSupportedTermuxArch(arch) {
 			log.Debugf("skipping termux.deb for %s as its not supported by termux", arch)
@@ -163,7 +162,7 @@ func create(ctx *context.Context, fpm config.NFPM, format string, binaries []*ar
 		)
 		infoArch = replacer.Replace(infoArch)
 		arch = replacer.Replace(arch)
-		bindDir = filepath.Join("/data/data/com.termux/files", bindDir)
+		fpm.Bindir = filepath.Join("/data/data/com.termux/files", fpm.Bindir)
 	}
 
 	overridden, err := mergeOverrides(fpm, format)
@@ -184,25 +183,17 @@ func create(ctx *context.Context, fpm config.NFPM, format string, binaries []*ar
 			"PackageName": packageName,
 		})
 
-	binDir, err := t.Apply(bindDir)
-	if err != nil {
+	if err := t.ApplyAll(
+		&fpm.Bindir,
+		&fpm.Homepage,
+		&fpm.Description,
+		&fpm.Maintainer,
+	); err != nil {
 		return err
 	}
 
-	homepage, err := t.Apply(fpm.Homepage)
-	if err != nil {
-		return err
-	}
-
-	description, err := t.Apply(fpm.Description)
-	if err != nil {
-		return err
-	}
-
-	maintainer, err := t.Apply(fpm.Maintainer)
-	if err != nil {
-		return err
-	}
+	// We cannot use t.ApplyAll on the following fields as they are shared
+	// across multiple nfpms.
 
 	debKeyFile, err := t.Apply(overridden.Deb.Signature.KeyFile)
 	if err != nil {
@@ -257,7 +248,7 @@ func create(ctx *context.Context, fpm config.NFPM, format string, binaries []*ar
 	if !fpm.Meta {
 		for _, binary := range binaries {
 			src := binary.Path
-			dst := filepath.Join(binDir, binary.Name)
+			dst := filepath.Join(fpm.Bindir, binary.Name)
 			log.WithField("src", src).WithField("dst", dst).Debug("adding binary to package")
 			contents = append(contents, &files.Content{
 				Source:      filepath.ToSlash(src),
@@ -282,10 +273,10 @@ func create(ctx *context.Context, fpm config.NFPM, format string, binaries []*ar
 		Release:         fpm.Release,
 		Prerelease:      fpm.Prerelease,
 		VersionMetadata: fpm.VersionMetadata,
-		Maintainer:      maintainer,
-		Description:     description,
+		Maintainer:      fpm.Maintainer,
+		Description:     fpm.Description,
 		Vendor:          fpm.Vendor,
-		Homepage:        homepage,
+		Homepage:        fpm.Homepage,
 		License:         fpm.License,
 		Changelog:       fpm.Changelog,
 		Overridables: nfpm.Overridables{

internal/pipe/nix/nix.go

@@ -130,9 +130,15 @@ func (p Pipe) doRun(ctx *context.Context, nix config.Nix, cl client.ReleaserURLT
 		return errNoRepoName
 	}
 
-	var err error
+	tp := tmpl.New(ctx)
 
-	nix.Name, err = tmpl.New(ctx).Apply(nix.Name)
+	err := tp.ApplyAll(
+		&nix.Name,
+		&nix.SkipUpload,
+		&nix.Homepage,
+		&nix.Description,
+		&nix.Path,
+	)
 	if err != nil {
 		return err
 	}
@@ -142,25 +148,6 @@ func (p Pipe) doRun(ctx *context.Context, nix config.Nix, cl client.ReleaserURLT
 		return err
 	}
 
-	nix.SkipUpload, err = tmpl.New(ctx).Apply(nix.SkipUpload)
-	if err != nil {
-		return err
-	}
-
-	nix.Homepage, err = tmpl.New(ctx).Apply(nix.Homepage)
-	if err != nil {
-		return err
-	}
-
-	nix.Description, err = tmpl.New(ctx).Apply(nix.Description)
-	if err != nil {
-		return err
-	}
-
-	nix.Path, err = tmpl.New(ctx).Apply(nix.Path)
-	if err != nil {
-		return err
-	}
 	if nix.Path == "" {
 		nix.Path = path.Join("pkgs", nix.Name, "default.nix")
 	}

internal/pipe/scoop/scoop.go

@@ -150,23 +150,16 @@ func doRun(ctx *context.Context, scoop config.Scoop, cl client.ReleaserURLTempla
 		return ErrIncorrectArchiveCount{scoop.Goamd64, scoop.IDs, archives}
 	}
 
-	name, err := tmpl.New(ctx).Apply(scoop.Name)
-	if err != nil {
-		return err
-	}
-	scoop.Name = name
+	tp := tmpl.New(ctx)
 
-	description, err := tmpl.New(ctx).Apply(scoop.Description)
-	if err != nil {
+	if err := tp.ApplyAll(
+		&scoop.Name,
+		&scoop.Description,
+		&scoop.Homepage,
+		&scoop.SkipUpload,
+	); err != nil {
 		return err
 	}
-	scoop.Description = description
-
-	homepage, err := tmpl.New(ctx).Apply(scoop.Homepage)
-	if err != nil {
-		return err
-	}
-	scoop.Homepage = homepage
 
 	ref, err := client.TemplateRef(tmpl.New(ctx).Apply, scoop.Repository)
 	if err != nil {
@@ -174,12 +167,6 @@ func doRun(ctx *context.Context, scoop config.Scoop, cl client.ReleaserURLTempla
 	}
 	scoop.Repository = ref
 
-	skipUpload, err := tmpl.New(ctx).Apply(scoop.SkipUpload)
-	if err != nil {
-		return err
-	}
-	scoop.SkipUpload = skipUpload
-
 	data, err := dataFor(ctx, scoop, cl, archives)
 	if err != nil {
 		return err

internal/pipe/snapcraft/snapcraft.go

@@ -154,16 +154,12 @@ func (Pipe) Run(ctx *context.Context) error {
 
 func doRun(ctx *context.Context, snap config.Snapcraft) error {
 	tpl := tmpl.New(ctx)
-	summary, err := tpl.Apply(snap.Summary)
-	if err != nil {
+	if err := tpl.ApplyAll(
+		&snap.Summary,
+		&snap.Description,
+	); err != nil {
 		return err
 	}
-	description, err := tpl.Apply(snap.Description)
-	if err != nil {
-		return err
-	}
-	snap.Summary = summary
-	snap.Description = description
 	if snap.Summary == "" && snap.Description == "" {
 		return pipe.Skip("no summary nor description were provided")
 	}
@@ -173,8 +169,7 @@ func doRun(ctx *context.Context, snap config.Snapcraft) error {
 	if snap.Description == "" {
 		return ErrNoDescription
 	}
-	_, err = exec.LookPath("snapcraft")
-	if err != nil {
+	if _, err := exec.LookPath("snapcraft"); err != nil {
 		return ErrNoSnapcraft
 	}
 

internal/pipe/winget/winget.go

@@ -104,11 +104,22 @@ func (p Pipe) doRun(ctx *context.Context, winget config.Winget, cl client.Releas
 
 	tp := tmpl.New(ctx)
 
-	var err error
-	winget.Publisher, err = tp.Apply(winget.Publisher)
+	err := tp.ApplyAll(
+		&winget.Publisher,
+		&winget.Name,
+		&winget.Author,
+		&winget.PublisherURL,
+		&winget.Homepage,
+		&winget.SkipUpload,
+		&winget.Description,
+		&winget.ShortDescription,
+		&winget.ReleaseNotesURL,
+		&winget.Path,
+	)
 	if err != nil {
 		return err
 	}
+
 	if winget.Publisher == "" {
 		return errNoPublisher
 	}
@@ -117,55 +128,15 @@ func (p Pipe) doRun(ctx *context.Context, winget config.Winget, cl client.Releas
 		return errNoLicense
 	}
 
-	winget.Name, err = tp.Apply(winget.Name)
-	if err != nil {
-		return err
-	}
-
-	winget.Author, err = tp.Apply(winget.Author)
-	if err != nil {
-		return err
-	}
-
-	winget.PublisherURL, err = tp.Apply(winget.PublisherURL)
-	if err != nil {
-		return err
-	}
-
-	winget.Homepage, err = tp.Apply(winget.Homepage)
-	if err != nil {
-		return err
-	}
-
 	winget.Repository, err = client.TemplateRef(tp.Apply, winget.Repository)
 	if err != nil {
 		return err
 	}
 
-	winget.SkipUpload, err = tp.Apply(winget.SkipUpload)
-	if err != nil {
-		return err
-	}
-
-	winget.Description, err = tp.Apply(winget.Description)
-	if err != nil {
-		return err
-	}
-
-	winget.ShortDescription, err = tp.Apply(winget.ShortDescription)
-	if err != nil {
-		return err
-	}
-
 	if winget.ShortDescription == "" {
 		return errNoShortDescription
 	}
 
-	winget.ReleaseNotesURL, err = tp.Apply(winget.ReleaseNotesURL)
-	if err != nil {
-		return err
-	}
-
 	winget.ReleaseNotes, err = tp.WithExtraFields(tmpl.Fields{
 		"Changelog": ctx.ReleaseNotes,
 	}).Apply(winget.ReleaseNotes)
@@ -180,10 +151,6 @@ func (p Pipe) doRun(ctx *context.Context, winget config.Winget, cl client.Releas
 		}
 	}
 
-	winget.Path, err = tp.Apply(winget.Path)
-	if err != nil {
-		return err
-	}
 	if winget.Path == "" {
 		winget.Path = filepath.Join("manifests", strings.ToLower(string(winget.Publisher[0])), winget.Publisher, winget.Name, ctx.Version)
 	}

internal/tmpl/tmpl.go

@@ -230,6 +230,20 @@ func (t *Template) Apply(s string) (string, error) {
 	return out.String(), err
 }
 
+// ApplyAll applies all the given strings against the Fields stored in the
+// template. Application stops as soon as an error is encountered.
+func (t *Template) ApplyAll(sps ...*string) error {
+	for _, sp := range sps {
+		s := *sp
+		result, err := t.Apply(s)
+		if err != nil {
+			return fmt.Errorf("failed to apply template: %s: %w", s, err)
+		}
+		*sp = result
+	}
+	return nil
+}
+
 func (t *Template) envOrDefault(name, value string) string {
 	s, ok := t.fields[env].(context.Env)[name]
 	if !ok {