fix(goals): prevent race condition on period reset and fix UTC boundary#345
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Priyanshu-byte-coder merged 1 commit intoMay 19, 2026
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Two bugs in the GET /api/goals handler caused goal progress to be lost
incorrectly at period boundaries.
Bug 1 - Race condition on period reset:
Promise.all fires all goal-reset DB writes concurrently. When two requests
arrive simultaneously (two browser tabs, mobile + desktop), both read the
same stale period_start, both decide a reset is needed, and both issue
UPDATE current=0. Any progress written between the two reads is silently
zeroed by the second update.
Fixed by adding .lt("period_start", periodStart) to the update so only
one concurrent write wins. The losing request re-fetches the current row
instead of returning a stale or double-zeroed value.
Bug 2 - Local timezone used for period boundary calculation:
getPeriodStart used getDay()/setDate()/setHours() which all operate in
the server's local timezone. On servers not running in UTC the weekly
Monday boundary and monthly first-of-month boundary shift by the UTC
offset, resetting goals a day early or late for affected users.
Fixed by switching to getUTCDay()/setUTCDate()/setUTCHours() and
Date.UTC() so the boundary is always calculated in UTC regardless of
server timezone.
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Both fixes are correct. The optimistic lock (.lt('period_start', ...)) ensures only one concurrent reset wins — the losing request re-fetches the already-reset row instead of silently zeroing progress. The UTC boundary fix (getUTCDay/setUTCHours) prevents server-timezone drift from shifting Monday to Sunday or Tuesday.
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Closes #344
What was wrong
Two bugs in `src/app/api/goals/route.ts` caused goal progress to be lost at period boundaries.
Bug 1 - Race condition:
`Promise.all` fires all goal-reset writes concurrently. Two simultaneous GET requests both read the same stale `period_start`, both issue `UPDATE current=0`, and the second write zeros out any progress recorded between the two reads.
Bug 2 - Local timezone boundary:
`getPeriodStart` used local-timezone methods (`getDay`, `setDate`, `setHours`, `Date(year, month, ...)`). On servers not running in UTC the weekly and monthly reset boundaries shift by the UTC offset, triggering resets a day early or late.
What changed
Files changed
Type of change