review

Author: ldez

Diff for: pkg/commands/internal/migrate/migrate_formatters.go

@@ -69,8 +69,9 @@ func toGoFumptSettings(old versionone.GoFumptSettings) versiontwo.GoFumptSetting
 func toGoImportsSettings(old versionone.GoImportsSettings) versiontwo.GoImportsSettings {
 	var localPrefixes []string
 
-	if ptr.Deref(old.LocalPrefixes) != "" {
-		localPrefixes = strings.Split(ptr.Deref(old.LocalPrefixes), ",")
+	prefixes := ptr.Deref(old.LocalPrefixes)
+	if prefixes != "" {
+		localPrefixes = strings.Split(prefixes, ",")
 	}
 
 	return versiontwo.GoImportsSettings{

Diff for: pkg/commands/internal/migrate/migrate_linter_names.go

@@ -1,6 +1,7 @@
 package migrate
 
 import (
+	"cmp"
 	"slices"
 
 	"github.com/golangci/golangci-lint/pkg/commands/internal/migrate/ptr"
@@ -718,9 +719,7 @@ func toNames(linters []LinterInfo) []string {
 		results = append(results, linter.Name)
 	}
 
-	slices.Sort(results)
-
-	return slices.Compact(results)
+	return Unique(results)
 }
 
 func removeLinters(linters, toRemove []LinterInfo) []LinterInfo {
@@ -852,9 +851,7 @@ func unknownLinterNames(names []string, linters []LinterInfo) []string {
 		}
 	}
 
-	slices.Sort(results)
-
-	return slices.Compact(results)
+	return Unique(results)
 }
 
 func convertStaticcheckLinterNames(names []string) []string {
@@ -869,9 +866,7 @@ func convertStaticcheckLinterNames(names []string) []string {
 		results = append(results, name)
 	}
 
-	slices.Sort(results)
-
-	return slices.Compact(results)
+	return Unique(results)
 }
 
 func onlyLinterNames(names []string) []string {
@@ -924,7 +919,9 @@ func convertAlternativeNames(names []string) []string {
 		results = append(results, name)
 	}
 
-	slices.Sort(results)
+	return Unique(results)
+}
 
-	return slices.Compact(results)
+func Unique[S ~[]E, E cmp.Ordered](s S) S {
+	return slices.Compact(slices.Sorted(slices.Values(s)))
 }

Diff for: pkg/commands/migrate.go

@@ -71,11 +71,11 @@ func newMigrateCommand(log logutils.Log, info BuildInfo) *migrateCommand {
 	setupConfigFileFlagSet(fs, &c.opts.LoaderOptions)
 
 	fs.StringVar(&c.opts.format, "format", "",
-		color.GreenString("By default, the file format is based on the configuration file extension.\n"+
-			"Overrides file format detection.\nIt can be 'yml', 'yaml', 'toml', 'json'."))
+		color.GreenString("Output file format.\nBy default, the format of the input configuration file is used.\n"+
+			"It can be 'yml', 'yaml', 'toml', or 'json'."))
 
 	fs.BoolVar(&c.opts.skipValidation, "skip-validation", false,
-		color.GreenString("Skip validation of the configuration file against the JSONSchema for v1."))
+		color.GreenString("Skip validation of the configuration file against the JSON Schema for v1."))
 
 	c.cmd = migrateCmd
 
@@ -101,7 +101,8 @@ func (c *migrateCommand) execute(_ *cobra.Command, _ []string) error {
 	c.log.Infof("Migrating v1 configuration file: %s", srcPath)
 
 	ext := filepath.Ext(srcPath)
-	if strings.TrimSpace(c.opts.format) != "" {
+
+	if c.opts.format != "" {
 		ext = "." + strings.TrimPrefix(c.opts.format, ".")
 	}
 
@@ -126,6 +127,13 @@ func (c *migrateCommand) execute(_ *cobra.Command, _ []string) error {
 }
 
 func (c *migrateCommand) preRunE(cmd *cobra.Command, _ []string) error {
+	switch strings.ToLower(c.opts.format) {
+	case "", "yml", "yaml", "toml", "json": //nolint:goconst // Constants are useless in this context.
+		// Valid format.
+	default:
+		return fmt.Errorf("unsupported format: %s", c.opts.format)
+	}
+
 	if c.opts.skipValidation {
 		return nil
 	}