enable fallback for {locale}.json

translation/translator.go

@@ -6,7 +6,6 @@ import (
 	"strings"
 
 	"github.com/spf13/cast"
-	"golang.org/x/exp/slices"
 	"golang.org/x/text/cases"
 	"golang.org/x/text/language"
 
@@ -92,8 +91,7 @@ func (t *Translator) Get(key string, options ...translationcontract.Option) stri
 	}
 
 	keyValue := getValue(t.loaded[locale]["*"], key)
-	// if the key is not found `{locale}.json` file, we will try to find it in
-	// the group files.
+	// If the key is found, return the translated line
 	if keyValue != nil {
 		line := cast.ToString(keyValue)
 		if line == "" {
@@ -110,25 +108,27 @@ func (t *Translator) Get(key string, options ...translationcontract.Option) stri
 		return line
 	}
 
-	// Parse the key into group and item.
+	// If the key is not found, parse it into a group and item and get the line.
 	group, item := parseKey(key)
-
-	// Here we will get the locale that should be used for the language line.
-	// If it doesn't exist, we will use the default locale which was given
-	// to us when the translator was instantiated.Then we can load the lines
-	// and return the value.
-	locales := []string{locale}
-	if fallback {
-		locales = t.appendFallbackLocale(locales)
+	line := t.getLine(locale, group, item, options...)
+	if line != "" {
+		return line
 	}
 
-	for _, loc := range locales {
-		line := t.getLine(loc, group, item, options...)
-		if line != "" {
-			return line
+	// If the key is not found in the current locale and fallback is enabled,
+	// try to load from fallback locale
+	fallbackLocale := t.GetFallback()
+	if (locale != fallbackLocale) && fallback && fallbackLocale != "" {
+		var fallbackOptions translationcontract.Option
+		if len(options) > 0 {
+			fallbackOptions = options[0]
 		}
+		fallbackOptions.Fallback = translationcontract.Bool(false)
+		fallbackOptions.Locale = fallbackLocale
+		return t.Get(key, fallbackOptions)
 	}
 
+	// Return the original key if no translation is found.
 	return t.key
 }
 
@@ -206,14 +206,6 @@ func (t *Translator) load(locale string, group string) error {
 	return nil
 }
 
-func (t *Translator) appendFallbackLocale(locales []string) []string {
-	fallbackLocale := t.GetFallback()
-	if fallbackLocale != "" && !slices.Contains(locales, fallbackLocale) {
-		locales = append(locales, fallbackLocale)
-	}
-	return locales
-}
-
 func (t *Translator) isLoaded(locale string, group string) bool {
 	if _, ok := t.loaded[locale]; !ok {
 		return false

translation/translator_test.go

@@ -175,6 +175,7 @@ func (t *TranslatorTestSuite) TestGet() {
 	translator = NewTranslator(t.ctx, t.mockLoader, "en", "fr", t.mockLog)
 	t.mockLoader.On("Load", "en", "*").Once().Return(map[string]any{}, ErrFileNotExist)
 	t.mockLoader.On("Load", "en", "test").Once().Return(map[string]any{}, ErrFileNotExist)
+	t.mockLoader.On("Load", "fr", "*").Once().Return(map[string]any{}, ErrFileNotExist)
 	t.mockLoader.On("Load", "fr", "test").Once().Return(map[string]any{
 		"nonexistentKey": "French translation",
 	}, nil)
@@ -184,6 +185,33 @@ func (t *TranslatorTestSuite) TestGet() {
 	})
 	t.Equal("French translation", translation)
 
+	// Case: Fallback to a different locale with fallback disabled
+	translator = NewTranslator(t.ctx, t.mockLoader, "en", "fr", t.mockLog)
+	t.mockLoader.On("Load", "en", "*").Once().Return(map[string]any{}, ErrFileNotExist)
+	t.mockLoader.On("Load", "en", "test").Once().Return(map[string]any{}, ErrFileNotExist)
+	translation = translator.Get("test.nonexistentKey", translationcontract.Option{
+		Fallback: translationcontract.Bool(false),
+		Locale:   "en",
+	})
+	t.Equal("test.nonexistentKey", translation)
+
+	// Case: use JSON file as fallback
+	translator = NewTranslator(t.ctx, t.mockLoader, "en", "fr", t.mockLog)
+	t.mockLoader.On("Load", "en", "*").Once().Return(map[string]any{
+		"nonexistentKey": "English translation",
+	}, nil)
+	t.mockLoader.On("Load", "en", "test").Once().Return(map[string]any{}, ErrFileNotExist)
+	t.mockLoader.On("Load", "fr", "*").Once().Return(map[string]any{
+		"test": map[string]any{
+			"nonexistentKey": "French translation",
+		},
+	}, nil)
+	translation = translator.Get("test.nonexistentKey", translationcontract.Option{
+		Fallback: translationcontract.Bool(true),
+		Locale:   "en",
+	})
+	t.Equal("French translation", translation)
+
 	translator = NewTranslator(t.ctx, t.mockLoader, "en", "en", t.mockLog)
 	t.mockLoader.On("Load", "en", "*").Once().Return(map[string]any{}, ErrFileNotExist)
 	t.mockLoader.On("Load", "en", "test").Once().Return(map[string]any{}, nil)