Try to fetch auth status before app is rendered

src/frontend/src/authStatusCheck.ts

@@ -0,0 +1,33 @@
+import { API_URL } from './config';
+import { actions } from './features/auth/store';
+import { type AppStore } from './store';
+
+const sleep = async (timeout: number): Promise<void> => {
+  await new Promise(resolve => {
+    setTimeout(() => {
+      resolve({});
+    }, timeout);
+  });
+};
+
+export const initAuthUserState = async (store: AppStore): Promise<void> => {
+  let retryCount = 0;
+  let waitInterval = 5000;
+  let response: Response;
+
+  do {
+    response = await fetch(`${API_URL}/api/v1/auth/status`);
+
+    if (response.ok) {
+      store.dispatch(actions.signIn());
+      return;
+    }
+
+    await sleep(waitInterval);
+
+    retryCount++;
+    waitInterval *= 2;
+  } while (retryCount < 4);
+
+  store.dispatch(actions.signOut());
+};

src/frontend/src/features/auth/hooks/useAuth.ts

@@ -22,13 +22,7 @@ interface UseAuthHookResult {
 export default function useAuth(): UseAuthHookResult {
   const user = useAppSelector(state => state.auth.user);
   const dispatch = useAppDispatch();
-
-  const { refetch, isFetching } = authApi.useGetStatusQuery(
-    {},
-    {
-      skip: !!user,
-    },
-  );
+  const [getAuthStatus, getAuthStatusRequest] = authApi.useLazyGetStatusQuery();
 
   const signIn = useCallback(() => {
     dispatch(actions.signIn());
@@ -60,16 +54,16 @@ export default function useAuth(): UseAuthHookResult {
   }, [signOut]);
 
   const completeLogin = useCallback(() => {
-    void refetch();
-  }, [refetch]);
+    void getAuthStatus({});
+  }, [getAuthStatus]);
 
   const completeLogout = useCallback(() => {
-    void refetch();
-  }, [refetch]);
+    void getAuthStatus({});
+  }, [getAuthStatus]);
 
   return {
     user,
-    isLoggingIn: isFetching,
+    isLoggingIn: getAuthStatusRequest.isFetching,
     login,
     logout,
     completeLogin,

src/frontend/src/index.tsx

@@ -3,7 +3,8 @@ import { initBrowserMockApi } from 'tests/mockApi';
 import { createRoot } from 'react-dom/client';
 import App from './App';
 import AppProvider from './AppProvider';
-import { GOOGLE_ANALYTICS_ENABLED, MSW_ENABLED } from './config';
+import { initAuthUserState } from './authStatusCheck';
+import { FAKE_AUTH_ENABLED, GOOGLE_ANALYTICS_ENABLED, MSW_ENABLED } from './config';
 import { initGoogleAnalytics } from './googleAnalytics';
 import store from './store';
 
@@ -16,6 +17,10 @@ void (async () => {
     initGoogleAnalytics();
   }
 
+  if (!FAKE_AUTH_ENABLED) {
+    await initAuthUserState(store);
+  }
+
   const container = document.getElementById('root') as HTMLElement;
   const root = createRoot(container);