Extended getLanguageNames()

Author: luca-vogels

package.json

@@ -1,6 +1,6 @@
 {
   "name": "lup-language",
-  "version": "2.2.6",
+  "version": "2.3.0",
   "description": "Node express middleware for detecting requested language",
   "files": [
     "lib/**/*"

src/__tests__/Basic.test.ts

@@ -1,7 +1,8 @@
+import path from 'path';
 import { ROOT } from 'lup-root';
 import * as lupLang from '../index';
 
-const TRANSLATIONS_DIR = ROOT + '/src/__tests__/translations';
+const TRANSLATIONS_DIR = path.join(ROOT, 'src', '__tests__', 'translations');
 
 test('Loading languages from translations directory', async () => {
   await expect(lupLang.reloadTranslations(TRANSLATIONS_DIR)).resolves.not.toThrow();
@@ -21,11 +22,23 @@ describe('Checking loaded translations', () => {
   });
 
   test('Language names correctly loaded', async () => {
-    const languageNames = await lupLang.getLanguageNames(TRANSLATIONS_DIR);
-    expect(languageNames).toBeInstanceOf(Object);
-    expect(Object.keys(languageNames).length).toBe(2);
-    expect(languageNames['de']).toEqual('Deutsch');
-    expect(languageNames['en']).toEqual('English');
+    const languageNativeNames = await lupLang.getLanguageNames(null, TRANSLATIONS_DIR);
+    expect(languageNativeNames).toBeInstanceOf(Object);
+    expect(Object.keys(languageNativeNames).length).toBe(2);
+    expect(languageNativeNames['de']).toEqual('Deutsch');
+    expect(languageNativeNames['en']).toEqual('English');
+
+    const languageNamesInDE = await lupLang.getLanguageNames('de', TRANSLATIONS_DIR);
+    expect(languageNamesInDE).toBeInstanceOf(Object);
+    expect(Object.keys(languageNamesInDE).length).toBe(2);
+    expect(languageNamesInDE['de']).toEqual('Deutsch');
+    expect(languageNamesInDE['en']).toEqual('Englisch');
+
+    const languageNamesInEN = await lupLang.getLanguageNames('en', TRANSLATIONS_DIR);
+    expect(languageNamesInEN).toBeInstanceOf(Object);
+    expect(Object.keys(languageNamesInEN).length).toBe(2);
+    expect(languageNamesInEN['de']).toEqual('German');
+    expect(languageNamesInEN['en']).toEqual('English');
   });
 
   test('Load single translation that exists', async () => {

src/__tests__/LanguageRouter.test.ts

@@ -1,7 +1,8 @@
+import path from 'path';
 import { ROOT } from 'lup-root';
 import { DEFAULTS, getLanguages, LanguageRouter } from '../index';
 
-const TRANSLATIONS_DIR = ROOT + '/src/__tests__/translations';
+const TRANSLATIONS_DIR = path.join(ROOT, 'src', '__tests__', 'translations');
 
 var handle: Function | any;
 var locales: string[];

src/__tests__/translations/de.json

@@ -1,4 +1,7 @@
 {
+    "LANGUAGE_NAME": "Deutsch",
+    "LANGUAGE_NAME_EN": "Englisch",
+
     "HelloWorld": "Hallo Welt",
     "OverwriteMe": "Hab ich gemacht"
 }

src/__tests__/translations/en.json

@@ -1,5 +1,7 @@
 {
-    "LANGUAGE_NAME": "English",
+    "LANGUAGE_NAME_DE": "German",
+    "LANGUAGE_NAME_EN": "English",
+    
     "HelloWorld": "Hello World",
     "OverwriteMe": "Did it"
 }

src/__tests__/translations/globals.json

@@ -1,6 +1,4 @@
 {
     "NAME": "lup-language",
-    "LANGUAGE_NAME_DE": "Deutsch",
-    "LANGUAGE_NAME_EN": "Should get overwritten",
     "OverwriteMe": "Overwrite me"
 }

src/index.ts

@@ -390,24 +390,42 @@ export const checkLanguage = async (
 };
 
 /**
- * Returns a map of all found languages and their native name.
- * Looksup following keys in the translations 'LANGUAGE_NAME_<lang>'.
+ * Returns a map of all found languages either in their native name or in a specified language.
+ * Looksup following keys in each translation file:
+ * - 'LANGUAGE_NAME_<LANG>': Name of the language <LANG> in the current language the file represents e.g. in `en.json` the key `LANGUAGE_NAME_DE` would contain `German`.
+ * - 'LANGUAGE_NAME': Native name of the language the file represents e.g. in `en.json` the key `LANGUAGE_NAME` would contain `English`.
+ * @param inLang Language code in which the language names should be returned (if null the native names will be returned).
  * @param translationsDir Relative path to directory containing JSON files with translations
  * @returns Promise that resolves to a map of language codes and their native names.
  */
 export const getLanguageNames = async (
+  inLang: string | null = null,
   translationsDir: string = DEFAULTS.TRANSLATIONS_DIR,
 ): Promise<{ [key: string]: string }> => {
   if (!translationsDir) translationsDir = DEFAULTS.TRANSLATIONS_DIR;
   if (!DICTONARY[translationsDir]) await reloadTranslations(translationsDir);
 
+  const PREFIX = 'LANGUAGE_NAME';
   const dict = DICTONARY[translationsDir];
+  const langs = LANGUAGES[translationsDir];
   const names: { [key: string]: string } = {};
-  const keyLocale = 'LANGUAGE_NAME';
 
-  for (const lang of LANGUAGES[translationsDir]) {
-    const keyGlobal = 'LANGUAGE_NAME_' + lang.toUpperCase();
-    names[lang] = dict[lang][keyLocale] || dict[lang][keyGlobal] || lang.toUpperCase();
+  if (inLang) {
+    inLang = inLang.trim().toLowerCase();
+    for (const lang of langs) {
+      const LANG = lang.toUpperCase();
+      names[lang] =
+        dict[inLang][PREFIX + '_' + LANG] ||
+        (inLang === lang && dict[inLang][PREFIX]) || // name of language in given name
+        dict[lang][PREFIX + '_' + LANG] ||
+        dict[lang][PREFIX] || // native name of the language (backup)
+        LANG; // fallback
+    }
+  } else {
+    for (const lang of langs) {
+      const LANG = lang.toUpperCase();
+      names[lang] = dict[lang][PREFIX] || dict[lang][PREFIX + '_' + LANG] || LANG;
+    }
   }
   return names;
 };

tsconfig.json

@@ -6,6 +6,7 @@
     "moduleResolution": "node",
     "declaration": true,
     "strict": true,
+    "esModuleInterop": true
   },
   "include": ["src"],
   "exclude": ["node_modules", "**/__tests__/*"]