add more unit test coverage for index.jsx

__tests__/index.test.jsx

@@ -1,11 +1,11 @@
 import { mount } from 'enzyme';
-import { main } from '../src/index';
+import { main, getLanguage } from '../src/index';
 
 const render = template => mount(template);
 const data = { custom_logo: 'foo', custom_login_info: '' }
 
 describe('index.jsx', () => {
-  test('initialization', async (done) => {
+  test('login loads when unauthenticated', async (done) => {
     const isAuthenticated = () => false;
     const getRoot = jest.fn(() => Promise.resolve({ data }));
 
@@ -13,7 +13,7 @@ describe('index.jsx', () => {
     const wrapper = await main(render, api);
 
     expect(api.getRoot).toHaveBeenCalled();
-    expect(wrapper.find('Dashboard')).toHaveLength(0);
+    expect(wrapper.find('App')).toHaveLength(0);
     expect(wrapper.find('Login')).toHaveLength(1);
 
     const { src } = wrapper.find('Login Brand img').props();
@@ -22,7 +22,7 @@ describe('index.jsx', () => {
     done();
   });
 
-  test('dashboard is loaded when authenticated', async (done) => {
+  test('app loads when authenticated', async (done) => {
     const isAuthenticated = () => true;
     const getRoot = jest.fn(() => Promise.resolve({ data }));
 
@@ -30,9 +30,22 @@ describe('index.jsx', () => {
     const wrapper = await main(render, api);
 
     expect(api.getRoot).toHaveBeenCalled();
-    expect(wrapper.find('Dashboard')).toHaveLength(1);
+    expect(wrapper.find('App')).toHaveLength(1);
+    expect(wrapper.find('Login')).toHaveLength(0);
+
+    wrapper.find('header a').simulate('click');
+    wrapper.update();
+
+    expect(wrapper.find('App')).toHaveLength(1);
     expect(wrapper.find('Login')).toHaveLength(0);
 
     done();
   });
+
+  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');
+  });
 });

src/index.jsx

@@ -60,21 +60,25 @@ const http = axios.create({ xsrfCookieName: 'csrftoken', xsrfHeaderName: 'X-CSRF
 // see: https://developer.mozilla.org/en-US/docs/Web/API/Navigator
 //
 
-const language = (navigator.languages && navigator.languages[0])
-  || navigator.language
-  || navigator.userLanguage;
+export function getLanguage (nav) {
+  const language = (nav.languages && nav.languages[0]) || nav.language || nav.userLanguage;
   const languageWithoutRegionCode = language.toLowerCase().split(/[_-]+/)[0];
-const catalogs = { en, ja };
+
+  return languageWithoutRegionCode;
+};
 
 //
 //  Function Main
 //
 
 export async function main (render, api) {
+  const catalogs = { en, ja };
+  const language = getLanguage(navigator);
+
   const el = document.getElementById('app');
-  // fetch additional config from server
   const { data: { custom_logo, custom_login_info } } = await api.getRoot();
 
+  const defaultRedirect = () => (<Redirect to="/home" />);
   const loginRoutes = (
     <Switch>
       <Route
@@ -94,7 +98,7 @@ export async function main (render, api) {
   return render(
     <HashRouter>
       <I18nProvider
-        language={languageWithoutRegionCode}
+        language={language}
         catalogs={catalogs}
       >
         <I18n>
@@ -102,8 +106,8 @@ export async function main (render, api) {
             <Background>
               {!api.isAuthenticated() ? loginRoutes : (
                 <Switch>
-                  <Route path="/login" render={() => (<Redirect to="/home" />)} />
-                  <Route exact path="/" render={() => (<Redirect to="/home" />)} />
+                  <Route path="/login" render={defaultRedirect} />
+                  <Route exact path="/" render={defaultRedirect} />
                   <Route
                     render={() => (
                       <App