Refactor language utility

Move the language helper out of RootProvider and into a utilities
module so that it can be more easiliy reused where needed. In some
cases we want the full language code so that logic has been moved
into a separate function.

awx/ui_next/src/RootProvider.jsx

@@ -3,23 +3,16 @@ import { I18nProvider } from '@lingui/react';
 
 import { HashRouter } from 'react-router-dom';
 
+import { getLanguageWithoutRegionCode } from '@util/language';
 import ja from '../build/locales/ja/messages';
 import en from '../build/locales/en/messages';
 
-export function getLanguage(nav) {
-  const language =
-    (nav.languages && nav.languages[0]) || nav.language || nav.userLanguage;
-  const languageWithoutRegionCode = language.toLowerCase().split(/[_-]+/)[0];
-
-  return languageWithoutRegionCode;
-}
-
 class RootProvider extends Component {
   render() {
     const { children } = this.props;
 
     const catalogs = { en, ja };
-    const language = getLanguage(navigator);
+    const language = getLanguageWithoutRegionCode(navigator);
 
     return (
       <HashRouter>

awx/ui_next/src/RootProvider.test.jsx

@@ -1,18 +0,0 @@
-import { getLanguage } from './RootProvider';
-
-describe('RootProvider.jsx', () => {
-  test('getLanguage returns the expected language code', () => {
-    expect(getLanguage({ languages: ['es-US'] })).toEqual('es');
-    expect(
-      getLanguage({
-        languages: ['es-US'],
-        language: 'fr-FR',
-        userLanguage: 'en-US',
-      })
-    ).toEqual('es');
-    expect(getLanguage({ language: 'fr-FR', userLanguage: 'en-US' })).toEqual(
-      'fr'
-    );
-    expect(getLanguage({ userLanguage: 'en-US' })).toEqual('en');
-  });
-});

awx/ui_next/src/util/language.js

@@ -0,0 +1,15 @@
+export function getLanguage(nav) {
+  if (nav.languages && nav.languages[0]) {
+    return nav.languages[0];
+  }
+  if (nav.language) {
+    return nav.language;
+  }
+  return nav.userLanguage;
+}
+
+export function getLanguageWithoutRegionCode(nav) {
+  return getLanguage(nav)
+    .toLowerCase()
+    .split(/[_-]+/)[0];
+}

awx/ui_next/src/util/language.test.jsx

@@ -0,0 +1,39 @@
+import { getLanguage, getLanguageWithoutRegionCode } from './language';
+
+describe('getLanguage', () => {
+  test('it returns the expected language code', () => {
+    expect(getLanguage({ languages: ['es-US'] })).toEqual('es-US');
+    expect(
+      getLanguage({
+        languages: ['es-US'],
+        language: 'fr-FR',
+        userLanguage: 'en-US',
+      })
+    ).toEqual('es-US');
+    expect(getLanguage({ language: 'fr-FR', userLanguage: 'en-US' })).toEqual(
+      'fr-FR'
+    );
+    expect(getLanguage({ userLanguage: 'en-US' })).toEqual('en-US');
+  });
+});
+
+describe('getLanguageWithoutRegionCode', () => {
+  test('it returns the expected (truncated) language code', () => {
+    expect(getLanguageWithoutRegionCode({ languages: ['es-US'] })).toEqual(
+      'es'
+    );
+    expect(
+      getLanguageWithoutRegionCode({
+        languages: ['es-US'],
+        language: 'fr-FR',
+        userLanguage: 'en-US',
+      })
+    ).toEqual('es');
+    expect(
+      getLanguageWithoutRegionCode({ language: 'fr-FR', userLanguage: 'en-US' })
+    ).toEqual('fr');
+    expect(getLanguageWithoutRegionCode({ userLanguage: 'en-US' })).toEqual(
+      'en'
+    );
+  });
+});