humanspeak / svelte-virtual-chat / 29095179293

92%

main: 92%

push

github

perf(chat): binary-search anchor capture and O(1) restore via prefix sums (#61)

Rewrite captureScrollAnchor and restoreScrollAnchor in chatAnchoring.ts to
use the ChatHeightCache prefix-sum queries (findVisibleStart binary search,
O(1) getIndexForId, O(1) getOffsetForIndex) instead of O(n) linear walks
(findIndex + accumulating loop). Behavior-preserving; public signatures
unchanged. Both functions now sync the cache internally before querying.

Closes #14.

Add regression tests: 5,000-message round-trip across a prepend, capture
past the end (fallback semantics), and stale/fresh-cache sync.

Co-authored-by: Claude Fable 5 <noreply@anthropic.com>

213 of 244 branches covered (87.3%)

Branch coverage included in aggregate %.

7 of 7 new or added lines in 1 file covered. (100.0%)

386 of 404 relevant lines covered (95.54%)

296.25 hits per line