Use a custom gettext FS to workaround the default plural formula

By default gettext-go uses the `nplurals=1; plural=0;` plural formula,
but this doesn't make sense for programs with default strings being in
English.

Use a default gettext.FileSystem backed by an OS one returning empty
data if there is no po / mo file. In this case the language will be
taken into account, while this is not the case using the
`nilTranslator`.

mgradm/main.go

@@ -9,12 +9,13 @@ import (
 
 	"github.com/chai2010/gettext-go"
 	"github.com/uyuni-project/uyuni-tools/mgradm/cmd"
+	l10n_utils "github.com/uyuni-project/uyuni-tools/shared/l10n/utils"
 	"github.com/uyuni-project/uyuni-tools/shared/utils"
 )
 
 // Run runs the `mgradm` root command.
 func Run() error {
-	gettext.BindLocale(gettext.New("mgradm", utils.LocaleRoot))
+	gettext.BindLocale(gettext.New("mgradm", utils.LocaleRoot, l10n_utils.New(utils.LocaleRoot)))
 	run, err := cmd.NewUyuniadmCommand()
 	if err != nil {
 		return err

mgrctl/main.go

@@ -9,12 +9,13 @@ import (
 
 	"github.com/chai2010/gettext-go"
 	"github.com/uyuni-project/uyuni-tools/mgrctl/cmd"
+	l10n_utils "github.com/uyuni-project/uyuni-tools/shared/l10n/utils"
 	"github.com/uyuni-project/uyuni-tools/shared/utils"
 )
 
 // Run runs the `mgrctl` root command.
 func Run() error {
-	gettext.BindLocale(gettext.New("mgrctl", utils.LocaleRoot))
+	gettext.BindLocale(gettext.New("mgrctl", utils.LocaleRoot, l10n_utils.New(utils.LocaleRoot)))
 	run, err := cmd.NewUyunictlCommand()
 	if err != nil {
 		return err

mgrpxy/main.go

@@ -9,12 +9,13 @@ import (
 
 	"github.com/chai2010/gettext-go"
 	"github.com/uyuni-project/uyuni-tools/mgrpxy/cmd"
+	l10n_utils "github.com/uyuni-project/uyuni-tools/shared/l10n/utils"
 	"github.com/uyuni-project/uyuni-tools/shared/utils"
 )
 
 // Run runs the `mgrpxy` root command.
 func Run() error {
-	gettext.BindLocale(gettext.New("mgrpxy", utils.LocaleRoot))
+	gettext.BindLocale(gettext.New("mgrpxy", utils.LocaleRoot, l10n_utils.New(utils.LocaleRoot)))
 	run, err := cmd.NewUyuniproxyCommand()
 	if err != nil {
 		return err

shared/l10n/utils/defaultfs.go

@@ -0,0 +1,50 @@
+// SPDX-FileCopyrightText: 2024 SUSE LLC
+//
+// SPDX-License-Identifier: Apache-2.0
+
+package l10n
+
+import "github.com/chai2010/gettext-go"
+
+// DefaultFS providing a empty data if no data is found.
+type DefaultFS struct {
+	osFs gettext.FileSystem
+	gettext.FileSystem
+}
+
+// New creates a new DefaultFS delegating to an OS FileSystem.
+func New(path string) *DefaultFS {
+	return &DefaultFS{
+		osFs: gettext.OS(path),
+	}
+}
+
+// LocaleList gets the list of locales from the underlying os FileSystem.
+func (f *DefaultFS) LocaleList() []string {
+	return f.osFs.LocaleList()
+}
+
+// LoadMessagesFile loads a messages or returns the content of an empty json file.
+func (f *DefaultFS) LoadMessagesFile(domain, lang, ext string) ([]byte, error) {
+	osFile, err := f.osFs.LoadMessagesFile(domain, lang, ext)
+	// Return an empty file by default
+	if err != nil {
+		return []byte("[]"), nil
+	}
+	return osFile, nil
+}
+
+// LoadResourceFile loads the resource file or returns empty data.
+func (f *DefaultFS) LoadResourceFile(domain, lang, ext string) ([]byte, error) {
+	osFile, err := f.osFs.LoadResourceFile(domain, lang, ext)
+	// Return an empty file by default
+	if err != nil {
+		return []byte{}, nil
+	}
+	return osFile, nil
+}
+
+// String returns a name of the FileSystem.
+func (f *DefaultFS) String() string {
+	return "DefaultFS"
+}

shared/utils/utils.go

@@ -28,7 +28,7 @@ func checkValueSize(value string, min int, max int) bool {
 	}
 
 	if len(value) < min {
-		fmt.Printf(NL("Has to be more than %d character long", "Has to be more that %d characters long", min), min)
+		fmt.Printf(NL("Has to be more than %d character long", "Has to be more than %d characters long", min), min)
 		return false
 	}
 	if len(value) > max {

shared/utils/utils_test.go

@@ -13,6 +13,8 @@ import (
 	"testing"
 
 	expect "github.com/Netflix/go-expect"
+	"github.com/chai2010/gettext-go"
+	l10n_utils "github.com/uyuni-project/uyuni-tools/shared/l10n/utils"
 )
 
 type askTestData struct {
@@ -24,6 +26,10 @@ type askTestData struct {
 }
 
 func TestAskIfMissing(t *testing.T) {
+	// Set english locale to not depend on the system one
+	gettext.BindLocale(gettext.New("", "", l10n_utils.New("")))
+	gettext.SetLanguage("en")
+
 	c, err := expect.NewConsole(expect.WithStdout(os.Stdout))
 	if err != nil {
 		t.Errorf("Failed to create fake console")
@@ -83,6 +89,10 @@ func TestAskIfMissing(t *testing.T) {
 }
 
 func TestAskPasswordIfMissing(t *testing.T) {
+	// Set english locale to not depend on the system one
+	gettext.BindLocale(gettext.New("", "", l10n_utils.New("")))
+	gettext.SetLanguage("en")
+
 	c, err := expect.NewConsole(expect.WithStdout(os.Stdout))
 	if err != nil {
 		t.Errorf("Failed to create fake console")