reactjs / reactjs/react.dev

[Typo]: "A stopwatch" example for useRef does not cleanup correctly

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type: typos
Dominant language
JavaScript
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Description

Summary

In "A stopwatch" example for useRef an interval is set in handleStart(). It is cleared in handleStop(). But if the component is unmounted after the interval is started, but without stopping it, it is never cleared, which means setNow can get called on an unmounted component.

Page

https://react.dev/reference/react/useRef#examples-value

Details

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First steps

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  4. Open a pull request that references the issue number.

Research direction

Open the useRef reference page at the linked example and inspect the “A stopwatch” code, starting with the interval created in handleStart() and stopped in handleStop(). Ensure the example also handles unmounting after start, then verify that the documented example no longer leaves the interval active when the component is removed.

Written by the indexing model from the issue text.

Assessment

Tech stack
javascript, react
Domain
documentation
Issue type
Bug
Difficulty
2/5
Estimated time
1-3 hours
Activity status
Stale
Clarity
Clearly specified
Newbie friendliness
55/100

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