fix(map): preserve language on refresh or app change

packages/earth-map/src/auth/auth0.tsx

@@ -161,13 +161,13 @@ export const Auth0Provider = ({
    */
   const login = (options = {}) => {
     SessionStorage.remove('ephemeral');
-    SessionStorage.remove('lang');
+
     return client.loginWithRedirect(options);
   };
 
   const logout = (options = {}) => {
     SessionStorage.remove('ephemeral');
-    SessionStorage.remove('lang');
+
     // force the user to log out of their identity provider;
     return client.logout({ ...options, federated: true });
   };

packages/earth-shared/src/components/user-menu/UserMenu.tsx

@@ -25,7 +25,7 @@ import compose from 'lodash/fp/compose';
 import noop from 'lodash/noop';
 import { getInitials } from '../../utils';
 
-import { useDomWatcher, Elang } from '@marapp/earth-shared';
+import { useDomWatcher, Elang, TranslationService } from '@marapp/earth-shared';
 
 import './styles.scss';
 
@@ -77,6 +77,11 @@ export const UserMenu = (props: IProps) => {
     i18n.changeLanguage(lang);
   };
 
+  const handleLogout = (e) => {
+    const defaultLanguage = TranslationService.getDefaultLanguage();
+    changeLanguage(e, defaultLanguage);
+  };
+
   const selectedLanguage = i18n.language;
 
   return (
@@ -188,7 +193,7 @@ export const UserMenu = (props: IProps) => {
                     </li>
 
                     <li className="marapp-qa-signout">
-                      <a onClick={compose(onLogout, toggleDrop)}>{t('Sign Out')}</a>
+                      <a onClick={compose(onLogout, handleLogout, toggleDrop)}>{t('Sign Out')}</a>
                     </li>
                   </>
                 ) : (

packages/earth-shared/src/translations/TranslationService.ts

@@ -34,11 +34,20 @@ import * as weglot from './weglot';
 
 interface ITranslationService {
   init(): void;
+  getDefaultLanguage(): string;
 }
 
 class TranslationService implements ITranslationService {
   constructor() {}
 
+  getDefaultLanguage() {
+    const {
+      fallbackLng: [defaultLanguage],
+    } = i18n.options;
+
+    return defaultLanguage || Elang.EN;
+  }
+
   init(weglotApiKey) {
     const lang = SessionStorage.get('lang') || Elang.EN;