fix(offline): use serviceWorker.controller directly for CHECK_ONLINE polling

Author: grega

src/hooks/useIsOnline.js

@@ -30,9 +30,8 @@ const useIsOnline = () => {
   // While offline, poll the SW every 3s to check if the network has returned, broadcast ONLINE if successful
   useEffect(() => {
     if (isOnline || !("serviceWorker" in navigator)) return;
-    const interval = setInterval(async () => {
-      const reg = await navigator.serviceWorker.ready;
-      reg.active?.postMessage({ type: "CHECK_ONLINE" });
+    const interval = setInterval(() => {
+      navigator.serviceWorker.controller?.postMessage({ type: "CHECK_ONLINE" });
     }, 3000);
     return () => clearInterval(interval);
   }, [isOnline]);

src/hooks/useIsOnline.test.js

@@ -19,9 +19,7 @@ describe("useIsOnline", () => {
 
     mockPostMessage = jest.fn();
     swEventTarget = new EventTarget();
-    swEventTarget.ready = Promise.resolve({
-      active: { postMessage: mockPostMessage },
-    });
+    swEventTarget.controller = { postMessage: mockPostMessage };
 
     // jsdom doesn't implement navigator.serviceWorker so provide a minimal stub
     Object.defineProperty(navigator, "serviceWorker", {