The reset I added guards on `hidden === 0`, and `hidden` can be NEGATIVE.
`useChipOverflowFit` keeps `visible` in state and re-decides in a layout effect,
so the render in which the chip set SHRINKS still carries the previous
measurement — delete three tags under an open "+N" and `chips.length - visible`
goes to -2, the equality never matches, and the flag survives the one window the
reset exists to close. The next re-fit brings the menu back on its own, which is
the original defect with an extra step. Clamped at all three lanes, with a test
that drives the shrink through the stale value.
Also: the Scheduler characterization banner said "the four tests below" and now
sits above six, the last two of which are genuine regression guards for the
range-refusal fix. A future mutation check would have read it, seen them go red,
and concluded the harness was broken rather than that the guard worked.
Both refused an out-of-range value by discarding it: the entry vanished, the box
snapped back to the server's number, and nothing said whether the save had
happened, been rejected, or been ignored. That is the house rule about honest
states, applied to a write instead of a read. They now keep the draft, mark the
field aria-invalid and name the range (HU+EN), and the Save control is disabled
rather than silently inert.
The interval editor also dropped a keyboard user's focus on every exit — Escape,
Cancel and Save all unmount the focused input — so it hands focus back to the
pencil that opened it, the pattern IssueComposer already uses.
Tests: the four interval-editor cases added in S2 are relabelled CHARACTERIZATION,
because they pass against the pre-sweep code too (the old effect was already
guarded by `editing`). The editor that genuinely lost typing to a poll is the
maintenance batch box, whose old effect had no guard at all, and it had no such
test — it does now, anchored on a value that follows the server so it cannot pass
on a page that simply has not polled yet.
Closes the burn-down. Hook suppressions 113 -> 34, `exhaustive-deps` 45 -> 2 (the target was
<10), and every one of the 34 survivors is an inline directive NAMING the invariant it
protects. The suppressions file is deleted, because a bulk file hides the next violation
instead of answering it — and it cannot hold a warning-level rule at all.
The sprint plan's three verdicts missed the answer that turned out to be the most common one:
adjust the state DURING RENDER. React re-runs the component and discards that pass rather than
committing it, so the stale frame an effect-based reset paints does not exist. Applied to the
Plex player's up-next card, the playlist view reset, the feed's optimistic overrides, the
channel banner's retry count, the download center's tab guard, the Plex search highlight, the
comfort-pin latch, Welcome's per-view outcome and the card pager's page clamp. It is legal only
for a component's own state — PlexBrowse's language commit resets PlexProvider's filters, so
that one stays an effect and says why.
Mirrors of a prop or query became derived values or `draft ?? server`:
- `downloadRow` had ui/Avatar's defect exactly — a boolean "poster failed" that an effect reset,
in rows recycled down a virtualized list, so one job's missing poster painted over the next
one's for a frame. Keyed by URL now.
- Scheduler's two number editors held a mirror an effect re-synced, on a page that POLLS — the
shape a poll can overwrite mid-edit. A draft while editing, the server's value otherwise; six
tests where there were none, the one behavioural change (the save button stops being dirty at
commit rather than at the echo) mutation-checked.
- SetupWizard's "no token" and WatchPage's "gone" are facts about the URL, so they are seeded and
derived rather than pushed into state by an effect that had to commit first.
Elsewhere: PlexInfo's rating chip was a component declared during render — a new component type
every render, so React remounted the subtree and dropped the focus on its filter button. Hoisted.
Feed's undo action and PlexPlayer's session reclaim both re-entered their own useCallback, which
the checker reads as a forward reference; both go through the ref idiom this file already uses.
BootGate's dep list was load-bearing for correctness — a re-run meant `location.reload()` — so
the "already adopted THIS identity" comparison now enforces it in code, with a test that fails
without it (the existing reload tests all install their spy too late to catch it).
One correction to the batch before this: keying ChatThread's and Messages' decrypt passes on
`q.data` instead of `q.dataUpdatedAt` was wrong. react-query's structural sharing makes it safe
in production, but the component must not melt down when something hands back a fresh object per
render — and Messages.keyboard.dom.test does exactly that, so the effect span the suite. Both are
back on the fetch as the trigger with the payload behind a ref, which is honest AND loop-proof;
the replaced comment had warned about precisely this.
CLAUDE.md gains four canonical-patterns rows for the above, and its "React 18" line is now true.
peter