Prevent isAdminMode from becoming undefined and ensure false is stored correctly

src/App.tsx

@@ -269,13 +269,13 @@ export function Layout() {
       const role = getUserRole();
       const state = store.getState();
       const privilegedRoles = state.config.settings.privilegedRoles;
-
-      dispatch(
-        setAuthorisation({
-          role,
-          isAdminUser: privilegedRoles.includes(role),
-        })
-      );
+      if (typeof role === 'string')
+        dispatch(
+          setAuthorisation({
+            role,
+            isAdminUser: privilegedRoles.includes(role),
+          })
+        );
     });
   }, [dispatch]);
   // We need to call forceUpdate if SciGateway tells us to rerender

src/parseTokens.ts

@@ -29,12 +29,25 @@ export const readSciGatewayToken = (): SciGatewayToken => {
   return null;
 };
 
-export const getUserRole = (): string => {
+/**
+ * Retrieves the user's role from the JWT stored in localStorage.
+ *
+ * If the user is authenticated, the JWT should contain a `role` claim.
+ * In that case, the function returns the role value. If the token is
+ * missing or cannot be parsed, the function returns `undefined`.
+ *
+ * If a token exists but the `role` field is not present in the decoded
+ * payload, the function returns the fallback role `"default"`.
+ *
+ * @returns {string | undefined} The user's role, "default" if no role
+ *          exists in the token, or `undefined` if the user is not authenticated.
+ */
+export const getUserRole = (): string | undefined => {
   const token = localStorage.getItem(MicroFrontendToken);
   if (token) {
     const parsedToken = JSON.parse(parseJwt(token));
     return parsedToken.role ?? 'default';
   }
 
-  return 'default';
+  return undefined;
 };

src/state/middleware/authorisationMiddleware.tsx

@@ -4,7 +4,7 @@ import { setAuthorisation, setIsAdminMode } from '../slices/authorisationSlice';
 import { RootState, StorageRegistry } from '../store';
 
 export const createAuthListenerMiddleware = (
-  getUserRoleFn: () => string,
+  getUserRoleFn: () => string | undefined,
   storageRegistryDict: StorageRegistry
 ) => {
   const middleware = createListenerMiddleware();
@@ -16,13 +16,13 @@ export const createAuthListenerMiddleware = (
       const privilegedRoles = state.config.settings.privilegedRoles;
 
       const role = getUserRoleFn();
-
-      listenerApi.dispatch(
-        setAuthorisation({
-          role,
-          isAdminUser: privilegedRoles.includes(role),
-        })
-      );
+      if (typeof role === 'string')
+        listenerApi.dispatch(
+          setAuthorisation({
+            role,
+            isAdminUser: privilegedRoles.includes(role),
+          })
+        );
     },
   });
 

src/state/slices/authorisationSlice.tsx

@@ -25,11 +25,15 @@ export const authSlice = createSlice({
       state.isAdminUser = action.payload.isAdminUser;
 
       if (!state.isAdminUser) {
-        state.isAdminMode = false;
+        state.isAdminMode = initialState.isAdminMode;
+      } else {
+        state.isAdminMode = state.isAdminMode ?? initialState.isAdminMode;
       }
     },
     setIsAdminMode(state, action: PayloadAction<boolean>) {
-      state.isAdminMode = state.isAdminUser ? action.payload : false;
+      state.isAdminMode = state.isAdminUser
+        ? action.payload
+        : initialState.isAdminMode;
     },
   },
 });

src/state/store.tsx

@@ -26,7 +26,7 @@ const rootReducer = combineReducers({
 
 export function configureAppStore(
   preloadedState?: Partial<RootState>,
-  getUserRoleFn: () => string = getUserRole,
+  getUserRoleFn: () => string | undefined = getUserRole,
   storageRegistryDict: StorageRegistry = storageRegistry
 ) {
   const authListenerMiddleware = createAuthListenerMiddleware(
@@ -44,16 +44,16 @@ export function configureAppStore(
   const mergedPreloaded: Partial<RootState> = {
     ...preloadedState,
     authorisation: {
-      ...(preloadedState?.authorisation ?? {}),
       ...(hydratedIsAdminMode !== undefined
         ? { isAdminMode: hydratedIsAdminMode }
-        : {}),
+        : initialAuthSlice),
+      ...(preloadedState?.authorisation ?? {}),
     } as typeof initialAuthSlice,
     criticality: {
-      ...(preloadedState?.criticality ?? {}),
       ...((hydratedIsCriticalMode !== undefined
         ? { isCriticalMode: hydratedIsCriticalMode }
-        : {}) as typeof initialCriticalState),
+        : initialCriticalState) as typeof initialCriticalState),
+      ...(preloadedState?.criticality ?? {}),
     },
   };