Isolate locale-handling functions from i18n interface

This changes allows to make a clean i18n package (without dependency on
a specific implementation of the translation package) that, in turn,
allows to export packages that internally use i18n with the minimal
dependency load.

Taskfile.yml

@@ -309,24 +309,24 @@ tasks:
   i18n:update:
     desc: Updates i18n files
     cmds:
-      - go run ./internal/i18n/cmd/main.go catalog generate . > ./internal/i18n/data/en.po
+      - go run ./internal/locales/cmd/main.go catalog generate . > ./internal/locales/data/en.po
 
   i18n:pull:
     desc: Pull i18n files from transifex
     cmds:
-      - go run ./internal/i18n/cmd/main.go transifex pull ./internal/i18n/data
+      - go run ./internal/locales/cmd/main.go transifex pull ./internal/locales/data
 
   i18n:push:
     desc: Push i18n files to transifex
     cmds:
-      - go run ./internal/i18n/cmd/main.go transifex push ./internal/i18n/data
+      - go run ./internal/locales/cmd/main.go transifex push ./internal/locales/data
 
   i18n:check:
     desc: Check if the i18n message catalog was updated
     cmds:
       - task: i18n:pull
-      - git add -N ./internal/i18n/data
-      - git diff --exit-code ./internal/i18n/data
+      - git add -N ./internal/locales/data
+      - git diff --exit-code ./internal/locales/data
 
   # Source: https://github.com/arduino/tooling-project-assets/blob/main/workflow-templates/assets/check-mkdocs-task/Taskfile.yml
   website:check:

commands/instances.go

@@ -38,6 +38,7 @@ import (
 	"github.com/arduino/arduino-cli/internal/arduino/sketch"
 	"github.com/arduino/arduino-cli/internal/arduino/utils"
 	"github.com/arduino/arduino-cli/internal/i18n"
+	"github.com/arduino/arduino-cli/internal/locales"
 	rpc "github.com/arduino/arduino-cli/rpc/cc/arduino/cli/commands/v1"
 	paths "github.com/arduino/go-paths-helper"
 	"github.com/sirupsen/logrus"
@@ -420,7 +421,7 @@ func (s *arduinoCoreServerImpl) Init(req *rpc.InitRequest, stream rpc.ArduinoCor
 	// language of the CLI if the locale is different
 	// after started.
 	if locale, ok, _ := s.settings.GetStringOk("locale"); ok {
-		i18n.Init(locale)
+		locales.Init(locale)
 	}
 
 	return nil

internal/i18n/i18n.go

@@ -15,31 +15,28 @@
 
 package i18n
 
-// Init initializes the i18n module, setting the locale according to this order of preference:
-// 1. Locale specified via the function call
-// 2. OS Locale
-// 3. en (default)
-func Init(configLocale string) {
-	locales := supportedLocales()
-	if configLocale != "" {
-		if locale := findMatchingLocale(configLocale, locales); locale != "" {
-			setLocale(locale)
-			return
-		}
-	}
-
-	if osLocale := getLocaleIdentifierFromOS(); osLocale != "" {
-		if locale := findMatchingLocale(osLocale, locales); locale != "" {
-			setLocale(locale)
-			return
-		}
-	}
-
-	setLocale("en")
+import "fmt"
+
+type Locale interface {
+	Get(msg string, args ...interface{}) string
+}
+
+type nullLocale struct{}
+
+func (n nullLocale) Parse([]byte) {}
+
+func (n nullLocale) Get(msg string, args ...interface{}) string {
+	return fmt.Sprintf(msg, args...)
+}
+
+var locale Locale = &nullLocale{}
+
+func SetLocale(l Locale) {
+	locale = l
 }
 
 // Tr returns msg translated to the selected locale
 // the msg argument must be a literal string
 func Tr(msg string, args ...interface{}) string {
-	return po.Get(msg, args...)
+	return locale.Get(msg, args...)
 }

internal/i18n/i18n_test.go

@@ -25,8 +25,9 @@ import (
 )
 
 func setPo(poFile string) {
-	po = gotext.NewPo()
-	po.Parse([]byte(poFile))
+	dict := gotext.NewPo()
+	dict.Parse([]byte(poFile))
+	SetLocale(dict)
 }
 
 func TestPoTranslation(t *testing.T) {
@@ -39,7 +40,7 @@ func TestPoTranslation(t *testing.T) {
 }
 
 func TestNoLocaleSet(t *testing.T) {
-	po = gotext.NewPo()
+	locale = gotext.NewPo()
 	require.Equal(t, "test-key", Tr("test-key"))
 }
 

internal/i18n/cmd/ast/parser.go → internal/locales/cmd/ast/parser.go

@@ -24,7 +24,7 @@ import (
 	"path/filepath"
 	"strconv"
 
-	"github.com/arduino/arduino-cli/internal/i18n/cmd/po"
+	"github.com/arduino/arduino-cli/internal/locales/cmd/po"
 )
 
 // GenerateCatalog generates the i18n message catalog for the go source files

internal/i18n/cmd/commands/catalog/generate_catalog.go → internal/locales/cmd/commands/catalog/generate_catalog.go

@@ -19,7 +19,7 @@ import (
 	"os"
 	"path/filepath"
 
-	"github.com/arduino/arduino-cli/internal/i18n/cmd/ast"
+	"github.com/arduino/arduino-cli/internal/locales/cmd/ast"
 	"github.com/spf13/cobra"
 )
 

internal/i18n/cmd/commands/root.go → internal/locales/cmd/commands/root.go

@@ -16,8 +16,8 @@
 package commands
 
 import (
-	"github.com/arduino/arduino-cli/internal/i18n/cmd/commands/catalog"
-	"github.com/arduino/arduino-cli/internal/i18n/cmd/commands/transifex"
+	"github.com/arduino/arduino-cli/internal/locales/cmd/commands/catalog"
+	"github.com/arduino/arduino-cli/internal/locales/cmd/commands/transifex"
 	"github.com/spf13/cobra"
 )
 

internal/i18n/cmd/main.go → internal/locales/cmd/main.go

@@ -19,7 +19,7 @@ import (
 	"fmt"
 	"os"
 
-	"github.com/arduino/arduino-cli/internal/i18n/cmd/commands"
+	"github.com/arduino/arduino-cli/internal/locales/cmd/commands"
 )
 
 func main() {

internal/i18n/convert.go → internal/locales/convert.go

@@ -13,7 +13,7 @@
 // Arduino software without disclosing the source code of your own applications.
 // To purchase a commercial license, send an email to [email protected].
 
-package i18n
+package locales
 
 import (
 	"regexp"

internal/i18n/convert_test.go → internal/locales/convert_test.go

@@ -13,7 +13,7 @@
 // Arduino software without disclosing the source code of your own applications.
 // To purchase a commercial license, send an email to [email protected].
 
-package i18n
+package locales
 
 import (
 	"fmt"

internal/i18n/detect.go → internal/locales/detect.go

@@ -13,7 +13,7 @@
 // Arduino software without disclosing the source code of your own applications.
 // To purchase a commercial license, send an email to [email protected].
 
-package i18n
+package locales
 
 import (
 	"os"

internal/i18n/detect_cgo_darwin.go → internal/locales/detect_cgo_darwin.go

@@ -15,7 +15,7 @@
 
 //go:build darwin && cgo
 
-package i18n
+package locales
 
 /*
 #cgo CFLAGS: -x objective-c

internal/i18n/detect_freebsd.go → internal/locales/detect_freebsd.go

@@ -13,7 +13,7 @@
 // Arduino software without disclosing the source code of your own applications.
 // To purchase a commercial license, send an email to [email protected].
 
-package i18n
+package locales
 
 func getLocaleIdentifier() string {
 	return getLocaleIdentifierFromEnv()

internal/i18n/detect_linux.go → internal/locales/detect_linux.go

@@ -13,7 +13,7 @@
 // Arduino software without disclosing the source code of your own applications.
 // To purchase a commercial license, send an email to [email protected].
 
-package i18n
+package locales
 
 func getLocaleIdentifier() string {
 	return getLocaleIdentifierFromEnv()

internal/i18n/detect_nocgo_darwin.go → internal/locales/detect_nocgo_darwin.go

@@ -15,7 +15,7 @@
 
 //go:build darwin && !cgo
 
-package i18n
+package locales
 
 func getLocaleIdentifier() string {
 	return getLocaleIdentifierFromEnv()

internal/i18n/detect_windows.go → internal/locales/detect_windows.go

@@ -13,7 +13,7 @@
 // Arduino software without disclosing the source code of your own applications.
 // To purchase a commercial license, send an email to [email protected].
 
-package i18n
+package locales
 
 import (
 	"strings"

internal/locales/i18n.go

@@ -0,0 +1,39 @@
+// This file is part of arduino-cli.
+//
+// Copyright 2020 ARDUINO SA (http://www.arduino.cc/)
+//
+// This software is released under the GNU General Public License version 3,
+// which covers the main part of arduino-cli.
+// The terms of this license can be found at:
+// https://www.gnu.org/licenses/gpl-3.0.en.html
+//
+// You can be released from the requirements of the above licenses by purchasing
+// a commercial license. Buying such a license is mandatory if you want to
+// modify or otherwise use the software for commercial activities involving the
+// Arduino software without disclosing the source code of your own applications.
+// To purchase a commercial license, send an email to [email protected].
+
+package locales
+
+// Init initializes the i18n module, setting the locale according to this order of preference:
+// 1. Locale specified via the function call
+// 2. OS Locale
+// 3. en (default)
+func Init(configLocale string) {
+	locales := supportedLocales()
+	if configLocale != "" {
+		if locale := findMatchingLocale(configLocale, locales); locale != "" {
+			setLocale(locale)
+			return
+		}
+	}
+
+	if osLocale := getLocaleIdentifierFromOS(); osLocale != "" {
+		if locale := findMatchingLocale(osLocale, locales); locale != "" {
+			setLocale(locale)
+			return
+		}
+	}
+
+	setLocale("en")
+}

internal/i18n/locale.go → internal/locales/locale.go

@@ -13,24 +13,19 @@
 // Arduino software without disclosing the source code of your own applications.
 // To purchase a commercial license, send an email to [email protected].
 
-package i18n
+package locales
 
 import (
 	"embed"
 	"strings"
 
+	"github.com/arduino/arduino-cli/internal/i18n"
 	"github.com/leonelquinteros/gotext"
 )
 
-var po *gotext.Po
-
 //go:embed data/*.po
 var contents embed.FS
 
-func init() {
-	po = gotext.NewPo()
-}
-
 func supportedLocales() []string {
 	var locales []string
 	files, err := contents.ReadDir("data")
@@ -75,6 +70,7 @@ func setLocale(locale string) {
 	if err != nil {
 		panic("Error reading embedded i18n data: " + err.Error())
 	}
-	po = gotext.NewPo()
-	po.Parse(poFile)
+	dict := gotext.NewPo()
+	dict.Parse(poFile)
+	i18n.SetLocale(dict)
 }

internal/i18n/locale_test.go → internal/locales/locale_test.go

@@ -13,7 +13,7 @@
 // Arduino software without disclosing the source code of your own applications.
 // To purchase a commercial license, send an email to [email protected].
 
-package i18n
+package locales
 
 import (
 	"testing"

main.go

@@ -27,6 +27,7 @@ import (
 	"github.com/arduino/arduino-cli/internal/cli/configuration"
 	"github.com/arduino/arduino-cli/internal/cli/feedback"
 	"github.com/arduino/arduino-cli/internal/i18n"
+	"github.com/arduino/arduino-cli/internal/locales"
 	rpc "github.com/arduino/arduino-cli/rpc/cc/arduino/cli/commands/v1"
 	"github.com/arduino/go-paths-helper"
 	"github.com/sirupsen/logrus"
@@ -67,7 +68,7 @@ func main() {
 	config := resp.GetConfiguration()
 
 	// Setup i18n
-	i18n.Init(config.GetLocale())
+	locales.Init(config.GetLocale())
 
 	// Setup command line parser with the server and settings
 	arduinoCmd := cli.NewCommand(srv)