Simplify locale package usage (refactoring)

12 files changed, 366 insertions, 219 deletions

diff --git a/locale/catalog.go b/locale/catalog.go
new file mode 100644
index 0000000..926298c
--- /dev/null
+++ b/locale/catalog.go
@@ -0,0 +1,36 @@
+// Copyright 2018 Frédéric Guillot. All rights reserved.
+// Use of this source code is governed by the Apache 2.0
+// license that can be found in the LICENSE file.
+
+package locale // import "miniflux.app/locale"
+
+import (
+	"encoding/json"
+	"fmt"
+)
+
+type translationDict map[string]interface{}
+type catalog map[string]translationDict
+
+var defaultCatalog catalog
+
+func init() {
+	defaultCatalog = make(catalog)
+
+	for language, data := range translations {
+		messages, err := parseTranslationDict(data)
+		if err != nil {
+			panic(err)
+		}
+
+		defaultCatalog[language] = messages
+	}
+}
+
+func parseTranslationDict(data string) (translationDict, error) {
+	var translations translationDict
+	if err := json.Unmarshal([]byte(data), &translations); err != nil {
+		return nil, fmt.Errorf("invalid translation file: %v", err)
+	}
+	return translations, nil
+}
diff --git a/locale/parser_test.go b/locale/catalog_test.go
index 619d8db..0be9995 100644
--- a/locale/parser_test.go
+++ b/locale/catalog_test.go
@@ -7,14 +7,14 @@ package locale // import "miniflux.app/locale"
 import "testing"
 
 func TestParserWithInvalidData(t *testing.T) {
-	_, err := parseCatalogMessages(`{`)
+	_, err := parseTranslationDict(`{`)
 	if err == nil {
 		t.Fatal(`An error should be returned when parsing invalid data`)
 	}
 }
 
 func TestParser(t *testing.T) {
-	translations, err := parseCatalogMessages(`{"k": "v"}`)
+	translations, err := parseTranslationDict(`{"k": "v"}`)
 	if err != nil {
 		t.Fatalf(`Unexpected parsing error: %v`, err)
 	}
diff --git a/locale/language.go b/locale/language.go
deleted file mode 100644
index 5738163..0000000
--- a/locale/language.go
+++ /dev/null
@@ -1,50 +0,0 @@
-// Copyright 2017 Frédéric Guillot. All rights reserved.
-// Use of this source code is governed by the Apache 2.0
-// license that can be found in the LICENSE file.
-
-package locale // import "miniflux.app/locale"
-
-import "fmt"
-
-// Language represents a language in the system.
-type Language struct {
-	language     string
-	translations catalogMessages
-}
-
-// Get fetch the translation for the given key.
-func (l *Language) Get(key string, args ...interface{}) string {
-	var translation string
-
-	str, found := l.translations[key]
-	if !found {
-		translation = key
-	} else {
-		translation = str.(string)
-	}
-
-	return fmt.Sprintf(translation, args...)
-}
-
-// Plural returns the translation of the given key by using the language plural form.
-func (l *Language) Plural(key string, n int, args ...interface{}) string {
-	translation := key
-	slices, found := l.translations[key]
-
-	if found {
-		pluralForm, found := pluralForms[l.language]
-		if !found {
-			pluralForm = pluralForms["default"]
-		}
-
-		index := pluralForm(n)
-		translations := slices.([]interface{})
-		translation = key
-
-		if len(translations) > index {
-			translation = translations[index].(string)
-		}
-	}
-
-	return fmt.Sprintf(translation, args...)
-}
diff --git a/locale/locale.go b/locale/locale.go
index 59174b0..a59d4c4 100755
--- a/locale/locale.go
+++ b/locale/locale.go
@@ -1,23 +1,9 @@
-// Copyright 2017 Frédéric Guillot. All rights reserved.
+// Copyright 2018 Frédéric Guillot. All rights reserved.
 // Use of this source code is governed by the Apache 2.0
 // license that can be found in the LICENSE file.
 
 package locale // import "miniflux.app/locale"
 
-import "miniflux.app/logger"
-
-// Load loads all translations.
-func Load() *Translator {
-	translator := NewTranslator()
-
-	for language, tr := range translations {
-		logger.Debug("Loading translation: %s", language)
-		translator.AddLanguage(language, tr)
-	}
-
-	return translator
-}
-
 // AvailableLanguages returns the list of available languages.
 func AvailableLanguages() map[string]string {
 	return map[string]string{
diff --git a/locale/locale_test.go b/locale/locale_test.go
index 28e2a80..9f49b60 100644
--- a/locale/locale_test.go
+++ b/locale/locale_test.go
@@ -1,103 +1,24 @@
-// Copyright 2017 Frédéric Guillot. All rights reserved.
+// Copyright 2018 Frédéric Guillot. All rights reserved.
 // Use of this source code is governed by the Apache 2.0
 // license that can be found in the LICENSE file.
+
 package locale // import "miniflux.app/locale"
 
 import "testing"
 
-func TestTranslateWithMissingLanguage(t *testing.T) {
-	translator := NewTranslator()
-	translation := translator.GetLanguage("en_US").Get("auth.username")
-
-	if translation != "auth.username" {
-		t.Errorf("Wrong translation, got %s", translation)
-	}
-}
-
-func TestTranslateWithExistingKey(t *testing.T) {
-	data := `{"auth.username": "Username"}`
-	translator := NewTranslator()
-	translator.AddLanguage("en_US", data)
-	translation := translator.GetLanguage("en_US").Get("auth.username")
+func TestAvailableLanguages(t *testing.T) {
+	results := AvailableLanguages()
+	for k, v := range results {
+		if k == "" {
+			t.Errorf(`Empty language key detected`)
+		}
 
-	if translation != "Username" {
-		t.Errorf("Wrong translation, got %s", translation)
+		if v == "" {
+			t.Errorf(`Empty language value detected`)
+		}
 	}
-}
-
-func TestTranslateWithMissingKey(t *testing.T) {
-	data := `{"auth.username": "Username"}`
-	translator := NewTranslator()
-	translator.AddLanguage("en_US", data)
-	translation := translator.GetLanguage("en_US").Get("auth.password")
-
-	if translation != "auth.password" {
-		t.Errorf("Wrong translation, got %s", translation)
-	}
-}
-
-func TestTranslateWithMissingKeyAndPlaceholder(t *testing.T) {
-	translator := NewTranslator()
-	translator.AddLanguage("fr_FR", "")
-	translation := translator.GetLanguage("fr_FR").Get("Status: %s", "ok")
-
-	if translation != "Status: ok" {
-		t.Errorf("Wrong translation, got %s", translation)
-	}
-}
-
-func TestTranslatePluralWithDefaultRule(t *testing.T) {
-	data := `{"number_of_users": ["Il y a %d utilisateur (%s)", "Il y a %d utilisateurs (%s)"]}`
-	translator := NewTranslator()
-	translator.AddLanguage("fr_FR", data)
-	language := translator.GetLanguage("fr_FR")
-
-	translation := language.Plural("number_of_users", 1, 1, "some text")
-	expected := "Il y a 1 utilisateur (some text)"
-	if translation != expected {
-		t.Errorf(`Wrong translation, got "%s" instead of "%s"`, translation, expected)
-	}
-
-	translation = language.Plural("number_of_users", 2, 2, "some text")
-	expected = "Il y a 2 utilisateurs (some text)"
-	if translation != expected {
-		t.Errorf(`Wrong translation, got "%s" instead of "%s"`, translation, expected)
-	}
-}
-
-func TestTranslatePluralWithRussianRule(t *testing.T) {
-	data := `{"key": ["из %d книги за %d день", "из %d книг за %d дня", "из %d книг за %d дней"]}`
-	translator := NewTranslator()
-	translator.AddLanguage("ru_RU", data)
-	language := translator.GetLanguage("ru_RU")
-
-	translation := language.Plural("key", 1, 1, 1)
-	expected := "из 1 книги за 1 день"
-	if translation != expected {
-		t.Errorf(`Wrong translation, got "%s" instead of "%s"`, translation, expected)
-	}
-
-	translation = language.Plural("key", 2, 2, 2)
-	expected = "из 2 книг за 2 дня"
-	if translation != expected {
-		t.Errorf(`Wrong translation, got "%s" instead of "%s"`, translation, expected)
-	}
-
-	translation = language.Plural("key", 5, 5, 5)
-	expected = "из 5 книг за 5 дней"
-	if translation != expected {
-		t.Errorf(`Wrong translation, got "%s" instead of "%s"`, translation, expected)
-	}
-}
-
-func TestTranslatePluralWithMissingTranslation(t *testing.T) {
-	translator := NewTranslator()
-	translator.AddLanguage("fr_FR", "")
-	language := translator.GetLanguage("fr_FR")
 
-	translation := language.Plural("number_of_users", 2)
-	expected := "number_of_users"
-	if translation != expected {
-		t.Errorf(`Wrong translation, got "%s" instead of "%s"`, translation, expected)
+	if _, found := results["en_US"]; !found {
+		t.Errorf(`We must have at least the default language (en_US)`)
 	}
 }
diff --git a/locale/parser.go b/locale/parser.go
deleted file mode 100644
index 03591c1..0000000
--- a/locale/parser.go
+++ /dev/null
@@ -1,21 +0,0 @@
-// Copyright 2018 Frédéric Guillot. All rights reserved.
-// Use of this source code is governed by the Apache 2.0
-// license that can be found in the LICENSE file.
-
-package locale // import "miniflux.app/locale"
-
-import (
-	"encoding/json"
-	"fmt"
-)
-
-type catalogMessages map[string]interface{}
-type catalog map[string]catalogMessages
-
-func parseCatalogMessages(data string) (catalogMessages, error) {
-	var translations catalogMessages
-	if err := json.Unmarshal([]byte(data), &translations); err != nil {
-		return nil, fmt.Errorf("invalid translation file: %v", err)
-	}
-	return translations, nil
-}
diff --git a/locale/plurals.go b/locale/plural.go
index c4e47cf..3b14c38 100644
--- a/locale/plurals.go
+++ b/locale/plural.go
@@ -1,12 +1,14 @@
-// Copyright 2017 Frédéric Guillot. All rights reserved.
+// Copyright 2018 Frédéric Guillot. All rights reserved.
 // Use of this source code is governed by the Apache 2.0
 // license that can be found in the LICENSE file.
 
 package locale // import "miniflux.app/locale"
 
+type pluralFormFunc func(n int) int
+
 // See https://localization-guide.readthedocs.io/en/latest/l10n/pluralforms.html
 // And http://www.unicode.org/cldr/charts/29/supplemental/language_plural_rules.html
-var pluralForms = map[string]func(n int) int{
+var pluralForms = map[string]pluralFormFunc{
 	// nplurals=2; plural=(n != 1);
 	"default": func(n int) int {
 		if n != 1 {
diff --git a/locale/plural_test.go b/locale/plural_test.go
new file mode 100644
index 0000000..e7694bd
--- /dev/null
+++ b/locale/plural_test.go
@@ -0,0 +1,63 @@
+// Copyright 2018 Frédéric Guillot. All rights reserved.
+// Use of this source code is governed by the Apache 2.0
+// license that can be found in the LICENSE file.
+
+package locale // import "miniflux.app/locale"
+
+import "testing"
+
+func TestPluralRules(t *testing.T) {
+	scenarios := map[string]map[int]int{
+		"default": map[int]int{
+			1: 0,
+			2: 1,
+			5: 1,
+		},
+		"ar_AR": map[int]int{
+			0:   0,
+			1:   1,
+			2:   2,
+			5:   3,
+			11:  4,
+			200: 5,
+		},
+		"cs_CZ": map[int]int{
+			1: 0,
+			2: 1,
+			5: 2,
+		},
+		"pl_PL": map[int]int{
+			1: 0,
+			2: 1,
+			5: 2,
+		},
+		"pt_BR": map[int]int{
+			1: 0,
+			2: 1,
+			5: 1,
+		},
+		"ru_RU": map[int]int{
+			1: 0,
+			2: 1,
+			5: 2,
+		},
+		"sr_RS": map[int]int{
+			1: 0,
+			2: 1,
+			5: 2,
+		},
+		"zh_CN": map[int]int{
+			1: 0,
+			5: 0,
+		},
+	}
+
+	for rule, values := range scenarios {
+		for input, expected := range values {
+			result := pluralForms[rule](input)
+			if result != expected {
+				t.Errorf(`Unexpected result for %q rule, got %d instead of %d for %d as input`, rule, result, expected, input)
+			}
+		}
+	}
+}
diff --git a/locale/printer.go b/locale/printer.go
new file mode 100644
index 0000000..ef04e05
--- /dev/null
+++ b/locale/printer.go
@@ -0,0 +1,67 @@
+// Copyright 2018 Frédéric Guillot. All rights reserved.
+// Use of this source code is governed by the Apache 2.0
+// license that can be found in the LICENSE file.
+
+package locale // import "miniflux.app/locale"
+
+import "fmt"
+
+// Printer converts translation keys to language-specific strings.
+type Printer struct {
+	language string
+}
+
+// Printf is like fmt.Printf, but using language-specific formatting.
+func (p *Printer) Printf(key string, args ...interface{}) string {
+	var translation string
+
+	str, found := defaultCatalog[p.language][key]
+	if !found {
+		translation = key
+	} else {
+		var valid bool
+		translation, valid = str.(string)
+		if !valid {
+			translation = key
+		}
+	}
+
+	return fmt.Sprintf(translation, args...)
+}
+
+// Plural returns the translation of the given key by using the language plural form.
+func (p *Printer) Plural(key string, n int, args ...interface{}) string {
+	choices, found := defaultCatalog[p.language][key]
+
+	if found {
+		var plurals []string
+
+		switch v := choices.(type) {
+		case []interface{}:
+			for _, v := range v {
+				plurals = append(plurals, fmt.Sprint(v))
+			}
+		case []string:
+			plurals = v
+		default:
+			return key
+		}
+
+		pluralForm, found := pluralForms[p.language]
+		if !found {
+			pluralForm = pluralForms["default"]
+		}
+
+		index := pluralForm(n)
+		if len(plurals) > index {
+			return fmt.Sprintf(plurals[index], args...)
+		}
+	}
+
+	return key
+}
+
+// NewPrinter creates a new Printer.
+func NewPrinter(language string) *Printer {
+	return &Printer{language}
+}
diff --git a/locale/printer_test.go b/locale/printer_test.go
new file mode 100644
index 0000000..1d8f58d
--- /dev/null
+++ b/locale/printer_test.go
@@ -0,0 +1,174 @@
+// Copyright 2018 Frédéric Guillot. All rights reserved.
+// Use of this source code is governed by the Apache 2.0
+// license that can be found in the LICENSE file.
+package locale // import "miniflux.app/locale"
+
+import "testing"
+
+func TestTranslateWithMissingLanguage(t *testing.T) {
+	defaultCatalog = catalog{}
+	translation := NewPrinter("invalid").Printf("missing.key")
+
+	if translation != "missing.key" {
+		t.Errorf(`Wrong translation, got %q`, translation)
+	}
+}
+
+func TestTranslateWithMissingKey(t *testing.T) {
+	defaultCatalog = catalog{
+		"en_US": translationDict{
+			"k": "v",
+		},
+	}
+
+	translation := NewPrinter("en_US").Printf("missing.key")
+	if translation != "missing.key" {
+		t.Errorf(`Wrong translation, got %q`, translation)
+	}
+}
+
+func TestTranslateWithExistingKey(t *testing.T) {
+	defaultCatalog = catalog{
+		"en_US": translationDict{
+			"auth.username": "Login",
+		},
+	}
+
+	translation := NewPrinter("en_US").Printf("auth.username")
+	if translation != "Login" {
+		t.Errorf(`Wrong translation, got %q`, translation)
+	}
+}
+
+func TestTranslateWithExistingKeyAndPlaceholder(t *testing.T) {
+	defaultCatalog = catalog{
+		"en_US": translationDict{
+			"key": "Test: %s",
+		},
+		"fr_FR": translationDict{
+			"key": "Test : %s",
+		},
+	}
+
+	translation := NewPrinter("fr_FR").Printf("key", "ok")
+	if translation != "Test : ok" {
+		t.Errorf(`Wrong translation, got %q`, translation)
+	}
+}
+
+func TestTranslateWithMissingKeyAndPlaceholder(t *testing.T) {
+	defaultCatalog = catalog{
+		"en_US": translationDict{
+			"auth.username": "Login",
+		},
+		"fr_FR": translationDict{
+			"auth.username": "Identifiant",
+		},
+	}
+
+	translation := NewPrinter("fr_FR").Printf("Status: %s", "ok")
+	if translation != "Status: ok" {
+		t.Errorf(`Wrong translation, got %q`, translation)
+	}
+}
+
+func TestTranslateWithInvalidValue(t *testing.T) {
+	defaultCatalog = catalog{
+		"en_US": translationDict{
+			"auth.username": "Login",
+		},
+		"fr_FR": translationDict{
+			"auth.username": true,
+		},
+	}
+
+	translation := NewPrinter("fr_FR").Printf("auth.username")
+	if translation != "auth.username" {
+		t.Errorf(`Wrong translation, got %q`, translation)
+	}
+}
+
+func TestTranslatePluralWithDefaultRule(t *testing.T) {
+	defaultCatalog = catalog{
+		"en_US": translationDict{
+			"number_of_users": []string{"%d user (%s)", "%d users (%s)"},
+		},
+		"fr_FR": translationDict{
+			"number_of_users": []string{"%d utilisateur (%s)", "%d utilisateurs (%s)"},
+		},
+	}
+
+	printer := NewPrinter("fr_FR")
+	translation := printer.Plural("number_of_users", 1, 1, "some text")
+	expected := "1 utilisateur (some text)"
+	if translation != expected {
+		t.Errorf(`Wrong translation, got %q instead of %q`, translation, expected)
+	}
+
+	translation = printer.Plural("number_of_users", 2, 2, "some text")
+	expected = "2 utilisateurs (some text)"
+	if translation != expected {
+		t.Errorf(`Wrong translation, got %q instead of %q`, translation, expected)
+	}
+}
+
+func TestTranslatePluralWithRussianRule(t *testing.T) {
+	defaultCatalog = catalog{
+		"en_US": translationDict{
+			"time_elapsed.years": []string{"%d year", "%d years"},
+		},
+		"ru_RU": translationDict{
+			"time_elapsed.years": []string{"%d год назад", "%d года назад", "%d лет назад"},
+		},
+	}
+
+	printer := NewPrinter("ru_RU")
+
+	translation := printer.Plural("time_elapsed.years", 1, 1)
+	expected := "1 год назад"
+	if translation != expected {
+		t.Errorf(`Wrong translation, got %q instead of %q`, translation, expected)
+	}
+
+	translation = printer.Plural("time_elapsed.years", 2, 2)
+	expected = "2 года назад"
+	if translation != expected {
+		t.Errorf(`Wrong translation, got %q instead of %q`, translation, expected)
+	}
+
+	translation = printer.Plural("time_elapsed.years", 5, 5)
+	expected = "5 лет назад"
+	if translation != expected {
+		t.Errorf(`Wrong translation, got %q instead of %q`, translation, expected)
+	}
+}
+
+func TestTranslatePluralWithMissingTranslation(t *testing.T) {
+	defaultCatalog = catalog{
+		"en_US": translationDict{
+			"number_of_users": []string{"%d user (%s)", "%d users (%s)"},
+		},
+		"fr_FR": translationDict{},
+	}
+	translation := NewPrinter("fr_FR").Plural("number_of_users", 2)
+	expected := "number_of_users"
+	if translation != expected {
+		t.Errorf(`Wrong translation, got %q instead of %q`, translation, expected)
+	}
+}
+
+func TestTranslatePluralWithInvalidValues(t *testing.T) {
+	defaultCatalog = catalog{
+		"en_US": translationDict{
+			"number_of_users": []string{"%d user (%s)", "%d users (%s)"},
+		},
+		"fr_FR": translationDict{
+			"number_of_users": "must be a slice",
+		},
+	}
+	translation := NewPrinter("fr_FR").Plural("number_of_users", 2)
+	expected := "number_of_users"
+	if translation != expected {
+		t.Errorf(`Wrong translation, got %q instead of %q`, translation, expected)
+	}
+}
diff --git a/locale/translations_test.go b/locale/translations_test.go
index f196a28..55775ba 100644
--- a/locale/translations_test.go
+++ b/locale/translations_test.go
@@ -9,16 +9,16 @@ import "testing"
 func TestAllLanguagesHaveCatalog(t *testing.T) {
 	for language := range AvailableLanguages() {
 		if _, found := translations[language]; !found {
-			t.Fatalf(`This language do not have a catalog: %s`, language)
+			t.Fatalf(`This language do not have a catalog: %q`, language)
 		}
 	}
 }
 
 func TestAllKeysHaveValue(t *testing.T) {
 	for language := range AvailableLanguages() {
-		messages, err := parseCatalogMessages(translations[language])
+		messages, err := parseTranslationDict(translations[language])
 		if err != nil {
-			t.Fatalf(`Parsing error language %s`, language)
+			t.Fatalf(`Parsing error for language %q`, language)
 		}
 
 		if len(messages) == 0 {
@@ -42,7 +42,7 @@ func TestAllKeysHaveValue(t *testing.T) {
 
 func TestMissingTranslations(t *testing.T) {
 	refLang := "en_US"
-	references, err := parseCatalogMessages(translations[refLang])
+	references, err := parseTranslationDict(translations[refLang])
 	if err != nil {
 		t.Fatal(`Unable to parse reference language`)
 	}
@@ -52,9 +52,9 @@ func TestMissingTranslations(t *testing.T) {
 			continue
 		}
 
-		messages, err := parseCatalogMessages(translations[language])
+		messages, err := parseTranslationDict(translations[language])
 		if err != nil {
-			t.Fatalf(`Parsing error language %s`, language)
+			t.Fatalf(`Parsing error for language %q`, language)
 		}
 
 		for key := range references {
diff --git a/locale/translator.go b/locale/translator.go
deleted file mode 100644
index 0c38c56..0000000
--- a/locale/translator.go
+++ /dev/null
@@ -1,31 +0,0 @@
-// Copyright 2017 Frédéric Guillot. All rights reserved.
-// Use of this source code is governed by the Apache 2.0
-// license that can be found in the LICENSE file.
-
-package locale // import "miniflux.app/locale"
-
-// Translator manage supported locales.
-type Translator struct {
-	locales catalog
-}
-
-// AddLanguage loads a new language into the system.
-func (t *Translator) AddLanguage(language, data string) (err error) {
-	t.locales[language], err = parseCatalogMessages(data)
-	return err
-}
-
-// GetLanguage returns the given language handler.
-func (t *Translator) GetLanguage(language string) *Language {
-	translations, found := t.locales[language]
-	if !found {
-		return &Language{language: language}
-	}
-
-	return &Language{language: language, translations: translations}
-}
-
-// NewTranslator creates a new Translator.
-func NewTranslator() *Translator {
-	return &Translator{locales: make(catalog)}
-}