Patient #5

Agent #5

CURED
Presenting Symptoms

Memory leak in React component, browser tab crashes after 10 minutes

Out of memory

Code Snippet:

useEffect(() => { setInterval(() => fetchData(), 1000); }, [])
Diagnosis
By Dr. Frontend-Guru (Frontend Expert)

The provided useEffect hook initializes a setInterval call that runs every 1000ms (1 second) to execute `fetchData()`. However, the interval is never cleared when the component unmounts. Because the dependency array `[]` is empty, the `setInterval` is only set up once on the initial mount. When the component unmounts, the interval continues to run in the background, repeatedly calling `fetchData()`. This leads to a memory leak as the component's state or references might not be properly garbage collected, and new network requests or data processing might accumulate, eventually causing an 'Out of memory' error and browser tab crash.

Treatment Plan

The primary treatment is to ensure that the `setInterval` is properly cleared when the component unmounts or when the effect needs to be re-run. This is achieved by returning a cleanup function from the `useEffect` hook. This cleanup function will be executed by React when the component unmounts or before the effect runs again (if dependencies change).

Treatment Timeline
9 events recorded

Patient #5 cured and discharged! Dr. Frontend-Guru is now available.

3 months ago

Dr. Frontend-Guru: Diagnosis - The provided useEffect hook initializes a setInterval call that runs every 1000ms (1 second) to execute `fetchData()`. However, the interval is never cleared when the component unmounts. Because the dependency array `[]` is empty, the `setInterval` is only set up once on the initial mount. When the component unmounts, the interval continues to run in the background, repeatedly calling `fetchData()`. This leads to a memory leak as the component's state or references might not be properly garbage collected, and new network requests or data processing might accumulate, eventually causing an 'Out of memory' error and browser tab crash.

3 months ago

Dr. Frontend-Guru: Treatment prescribed. Sending to Pharmacy...

3 months ago

Dr. Discharge: Verifying treatment...

3 months ago

Nurse Triage: Patient experiencing a memory leak within a React component, leading to browser tab crashes due to 'Out of memory' errors. Code snippet available for review.. Severity: HIGH. Paging Frontend Expert...

3 months ago

Dr. Frontend Expert assigned to Patient #5

3 months ago

Dr. Frontend-Guru: Let me examine your symptoms...

3 months ago

Patient #5 admitted with critical severity symptoms

3 months ago

Nurse Triage: Analyzing symptoms...

3 months ago

Patient Information

Severity

critical

Admitted

3 months ago

Discharged

3 months ago

Physician

Dr. Frontend-Guru

Frontend Expert

Treatment Successful

Patient has been cured and discharged

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