fix: keep session when refresh fails on network error or 5xx (WealthLedger/frontend#97)

src/features/auth/model/auth.vm.ts

@@ -5,6 +5,9 @@ import { apiClient, configureAuthClient, type paths } from "@/shared/api";
 
 import { type User } from "./auth-context";
 
+// A 5xx or network error means the server is unreachable, not that the session ended.
+const HTTP_SERVER_ERROR = 500;
+
 type Authentication
 	= paths["/api/v1/auth/login"]["post"]["responses"][200]["content"]["application/json"];
 
@@ -32,6 +35,8 @@ function useAuthProviderVm() {
 	const accessTokenRef = useRef<string | undefined>(undefined);
 	const [ready, setReady] = useState(false);
 	const [signedOut, setSignedOut] = useState(false);
+	const [unavailable, setUnavailable] = useState(false);
+	const unavailableRef = useRef(false);
 
 	const generationRef = useRef(0);
 	const userRef = useRef<undefined | User>(undefined);
@@ -49,12 +54,18 @@ function useAuthProviderVm() {
 		return next;
 	}, []);
 
+	const markUnavailable = useCallback((isUnavailable: boolean) => {
+		unavailableRef.current = isUnavailable;
+		setUnavailable(isUnavailable);
+	}, []);
+
 	const applyAuthentication = useCallback(
 		(authentication: Authentication) => {
 			const changedIdentity
 				= userRef.current && userRef.current.id !== authentication.user.id;
 
 			setSignedOut(false);
+			markUnavailable(false);
 			accessTokenRef.current = authentication.accessToken;
 
 			if (changedIdentity) {
@@ -67,16 +78,17 @@ function useAuthProviderVm() {
 			userRef.current = authentication.user;
 			setUser(authentication.user);
 		},
-		[queryClient],
+		[markUnavailable, queryClient],
 	);
 
 	const clearSession = useCallback(() => {
+		markUnavailable(false);
 		generationRef.current += 1;
 		userRef.current = undefined;
 		setUser(undefined);
 		accessTokenRef.current = undefined;
 		queryClient.clear();
-	}, [queryClient]);
+	}, [markUnavailable, queryClient]);
 
 	const refresh = useCallback((): Promise<boolean> => {
 		if (refreshPromiseRef.current) return refreshPromiseRef.current;
@@ -86,11 +98,12 @@ function useAuthProviderVm() {
 			if (started !== generationRef.current) return false;
 
 			try {
-				const { data } = await apiClient.POST("/api/v1/auth/refresh");
+				const { data, response } = await apiClient.POST("/api/v1/auth/refresh");
 				if (started !== generationRef.current) return false;
 
 				if (!data) {
-					clearSession();
+					if (response.status >= HTTP_SERVER_ERROR) markUnavailable(true);
+					else clearSession();
 
 					return false;
 				}
@@ -100,7 +113,7 @@ function useAuthProviderVm() {
 				return true;
 			}
 			catch {
-				if (started === generationRef.current) clearSession();
+				if (started === generationRef.current) markUnavailable(true);
 
 				return false;
 			}
@@ -112,7 +125,7 @@ function useAuthProviderVm() {
 		refreshPromiseRef.current = pending;
 
 		return pending;
-	}, [applyAuthentication, clearSession, serialize]);
+	}, [applyAuthentication, clearSession, markUnavailable, serialize]);
 
 	useEffect(() => {
 		void refresh().finally(() => setReady(true));
@@ -146,6 +159,7 @@ function useAuthProviderVm() {
 			clear: clearSession,
 			generation: () => generationRef.current,
 			refresh,
+			unavailable: () => unavailableRef.current,
 		});
 	});
 	useEffect(() => () => configureAuthClient(), []);
@@ -157,7 +171,9 @@ function useAuthProviderVm() {
 		ready,
 		register: (email: string, password: string) =>
 			authenticate("/api/v1/auth/register", email, password),
+		retry: () => void refresh(),
 		signedOut,
+		unavailable,
 		user,
 	};