MM-54556: Integrate wip i18n languages (#24308)

* merge languages from https://github.com/mattermost/i18n-wip

* allow only supported server locales

* Revert "merge languages from https://github.com/mattermost/i18n-wip"

This reverts commit 36de545102faffe1e8ba943decdab04bc4f5a55c. We'll let
weblate populate these on start instead.

* copy fileutils to public/utils

---------

Co-authored-by: Mattermost Build <build@mattermost.com>

server/public/shared/i18n/i18n_test.go

@@ -4,12 +4,17 @@
 package i18n
 
 import (
+	"fmt"
+	"os"
+	"path/filepath"
 	"testing"
 
 	"github.com/mattermost/go-i18n/i18n/bundle"
 	"github.com/mattermost/go-i18n/i18n/language"
 	"github.com/mattermost/go-i18n/i18n/translation"
+	"github.com/mattermost/mattermost/server/public/utils"
 	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
 )
 
 var htmlTestTranslationBundle *bundle.Bundle
@@ -67,3 +72,155 @@ func TestEscapeForHTML(t *testing.T) {
 		})
 	}
 }
+
+func TestInitTranslationsWithDir(t *testing.T) {
+	i18nDir, found := utils.FindDir("server/i18n")
+	require.True(t, found, "unable to find i18n dir")
+
+	setup := func(t *testing.T, localesToCopy map[string]string) string {
+		tempDir, err := os.MkdirTemp(os.TempDir(), "TestGetTranslationFuncForDir")
+		require.NoError(t, err, "unable to create temporary directory")
+
+		t.Cleanup(func() {
+			err = os.RemoveAll(tempDir)
+			require.NoError(t, err)
+		})
+
+		for locale, fromLocale := range localesToCopy {
+			err = utils.CopyFile(
+				filepath.Join(i18nDir, fmt.Sprintf("%s.json", fromLocale)),
+				filepath.Join(tempDir, fmt.Sprintf("%s.json", locale)),
+			)
+			require.NoError(t, err)
+		}
+
+		return tempDir
+	}
+
+	t.Run("unsupported locale ignored", func(t *testing.T) {
+		tempDir := setup(t, map[string]string{"en": "en", "fr": "fr", "zz": "en"})
+
+		err := initTranslationsWithDir(tempDir)
+		require.NoError(t, err)
+
+		_, found := locales["zz"]
+		require.False(t, found, "should have ignored unsupported locale")
+	})
+
+	t.Run("malformed, unsupported locale ignored", func(t *testing.T) {
+		tempDir := setup(t, map[string]string{"en": "en", "fr": "fr", "zz": "en"})
+
+		err := os.WriteFile(filepath.Join(tempDir, "xx.json"), []byte{'{'}, os.ModePerm)
+		require.NoError(t, err)
+
+		err = initTranslationsWithDir(tempDir)
+		require.NoError(t, err)
+
+		_, found := locales["xx"]
+		require.False(t, found, "should have ignored malformed, unsupported locale")
+	})
+
+	t.Run("malformed, supported locale causes error", func(t *testing.T) {
+		tempDir := setup(t, map[string]string{"fr": "fr", "zz": "en"})
+
+		err := os.WriteFile(filepath.Join(tempDir, "en.json"), []byte{'{'}, os.ModePerm)
+		require.NoError(t, err)
+
+		err = initTranslationsWithDir(tempDir)
+		require.Error(t, err, "should have failed to load malformed, supported locale")
+	})
+
+	t.Run("known locales loaded ", func(t *testing.T) {
+		tempDir := setup(t, map[string]string{"en": "en", "fr": "fr"})
+
+		err := initTranslationsWithDir(tempDir)
+		require.NoError(t, err)
+
+		_, found := locales["en"]
+		require.True(t, found, "should have found en locale")
+		_, found = locales["fr"]
+		require.True(t, found, "should have found fr locale")
+		_, found = locales["es"]
+		require.False(t, found, "should not have found unloaded es locale")
+	})
+}
+
+func TestGetTranslationFuncForDir(t *testing.T) {
+	i18nDir, found := utils.FindDir("server/i18n")
+	require.True(t, found, "unable to find i18n dir")
+
+	setup := func(t *testing.T, localesToCopy map[string]string) string {
+		tempDir, err := os.MkdirTemp(os.TempDir(), "TestGetTranslationFuncForDir")
+		require.NoError(t, err, "unable to create temporary directory")
+
+		t.Cleanup(func() {
+			err = os.RemoveAll(tempDir)
+			require.NoError(t, err)
+		})
+
+		for locale, fromLocale := range localesToCopy {
+			err = utils.CopyFile(
+				filepath.Join(i18nDir, fmt.Sprintf("%s.json", fromLocale)),
+				filepath.Join(tempDir, fmt.Sprintf("%s.json", locale)),
+			)
+			require.NoError(t, err)
+		}
+
+		return tempDir
+	}
+
+	t.Run("unknown locale falls back to english", func(t *testing.T) {
+		tempDir := setup(t, map[string]string{"en": "en", "fr": "fr", "zz": "en"})
+
+		translationFunc, err := GetTranslationFuncForDir(tempDir)
+		require.NoError(t, err)
+		require.NotNil(t, translationFunc)
+
+		require.Equal(t, "December", translationFunc("unknown")("December"))
+	})
+
+	t.Run("unsupported locale falls back to english", func(t *testing.T) {
+		tempDir := setup(t, map[string]string{"en": "en", "fr": "fr", "zz": "en"})
+
+		translationFunc, err := GetTranslationFuncForDir(tempDir)
+		require.NoError(t, err)
+		require.NotNil(t, translationFunc)
+
+		require.Equal(t, "December", translationFunc("zz")("December"))
+	})
+
+	t.Run("malformed, unsupported locale ignored and falls back to english", func(t *testing.T) {
+		tempDir := setup(t, map[string]string{"en": "en", "fr": "fr", "zz": "en"})
+
+		err := os.WriteFile(filepath.Join(tempDir, "xx.json"), []byte{'{'}, os.ModePerm)
+		require.NoError(t, err)
+
+		translationFunc, err := GetTranslationFuncForDir(tempDir)
+		require.NoError(t, err)
+		require.NotNil(t, translationFunc)
+
+		require.Equal(t, "December", translationFunc("xx")("December"))
+	})
+
+	t.Run("malformed, supported locale causes error", func(t *testing.T) {
+		tempDir := setup(t, map[string]string{"fr": "fr", "zz": "en"})
+
+		err := os.WriteFile(filepath.Join(tempDir, "en.json"), []byte{'{'}, os.ModePerm)
+		require.NoError(t, err)
+
+		translationFunc, err := GetTranslationFuncForDir(tempDir)
+		require.Error(t, err)
+		require.Nil(t, translationFunc)
+	})
+
+	t.Run("known locale matches", func(t *testing.T) {
+		tempDir := setup(t, map[string]string{"en": "en", "fr": "fr"})
+
+		translationFunc, err := GetTranslationFuncForDir(tempDir)
+		require.NoError(t, err)
+		require.NotNil(t, translationFunc)
+
+		require.Equal(t, "Décembre", translationFunc("fr")("December"))
+		require.Equal(t, "December", translationFunc("en")("December"))
+	})
+}