[BUG]: Face scan timeout uses stale state and may incorrectly transition successful scans to error state

[Priyanshu1-62]

Target file: frontend/nyaysetu-frontend/src/components/auth/FaceLoginModal.jsx

Description

• The biometric login flow starts a 45-second timeout when face scanning begins.
• The timeout callback captures the values of step and faceDetected at the moment the timeout is created.
• The scanning state, being asynchronous in nature, can update after the moment timeout is captured, and timeout callback may still evaluate the outdated values when it executes.
• This can lead to incorrect timeout error even on successful authentication flow.

Current behavior

• The timeout callback depends on state values captured when scanning starts:

setTimeout(() => {
    if (interval) clearInterval(interval);
    if (step === 'scanning' && !faceDetected) {
        setStep('error');
        setMessage('Biometric timeout. Signal not acquired.');
    }
 }, 45000);

• Timeout callback relies on state values captured by the timeout closure.
• Outdated timeout callbacks can lead to an incorrect timeout flow.

Proposed Solution

• Manage the timeout lifecycle explicitly using a dedicated ref variable.
• Store the timeout ID when scanning starts.
• Clear the timeout immediately when a valid face is detected.
• Ensure timeout execution only occurs while the current scan session is active.

Benifits

• Eliminates race conditions caused by stale closures.
• Improves reliability and predictability of the biometric login flow.
• Prevents intermittent, hard-to-reproduce authentication failures.

Additional details

• Labels: GSSoC'2026, type:bug, type:enhancement, frontend
• I want to work on this issue.

[Priyanshu1-62]

Hi @viru0909-dev ,
Please /assign me this issue under GSSoC'2026, thank you.

[Janeeshareddy]

/assign

[github-actions]

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Make sure to read our Contributing Guidelines and submit your PR within the GSSoC timeframe. Happy coding! 🚀

[github-actions]

Hi @Janeeshareddy, this issue has been unassigned due to no activity/updates for 3 days. This keeps the repository active and open for other GSSoC contributors! Feel free to request it again if you are ready to submit a PR soon.