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PR REVIEWMissing useEffect Cleanup — Memory Leak on Unmount#519NotionLinear
⏱ 00:00Junior~10 min
PULL REQUEST
Open#519 · 1 commit
Missing useEffect Cleanup — Memory Leak on Unmount
junior-dev-99 wants to mergefeature/notification-live-poll→main
JU
junior-dev-99
1 file changed · 4 hours ago
YOUR MISSION
A junior dev added a live-poll feature to the notifications panel. After navigating away, the browser console starts throwing "Can't perform a React state update on an unmounted component" and memory usage climbs. Spot the issue.
Junior~10 min
HINTS (0/3 used)
REVIEWING AS
SR
Senior Engineer
@ Notion · Backend Platform
src / components / NotificationsPanel.tsx+3 −0
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const [notifications, setNotifications] = useState([]);
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useEffect(() => {
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fetchNotifications().then(setNotifications);
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setInterval(() => {
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fetchNotifications().then(setNotifications);
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}, 5000);
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}, []);
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return <NotificationList items={notifications} />;
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