hermes-agent/apps/desktop/src/components
brooklyn! c856f36459
perf(desktop): kill the layout-thrash cascade on session switch (#66033)
Follow-up to #65890 (router transitions off) and #65898 (structural
compare + first-paint budget): profiling the switch path on real 1000+-
message sessions with a new CDP harness showed the remaining freeze is
NOT markdown rendering — it's a forced-reflow cascade from mount-time
layout reads interleaved with style writes across the transcript's
layout effects, plus the first-paint budget cut landing too late to
stop the full-budget commit.

Measured on the two largest local sessions (996 and 1363 messages),
main-thread longtask totals per switch: warm 2450ms -> 557ms and
1158ms -> 194ms; first paint 1690ms -> 444ms. Harness:
scripts/profile-session-switch.mjs (same CDP family as
profile-real-stream.mjs).

- use-resize-observer: drop the synchronous initial callback and ride
  the observer's spec-guaranteed first delivery instead (same frame,
  after layout, before paint). The sync call ran while the commit's
  layout was dirty, so every size read in a callback forced a full
  reflow — with one instance per user bubble (measureClamp read
  scrollHeight, then WROTE --human-msg-full, re-dirtying layout for the
  next bubble), the switch commit thrashed for over a second. Inside RO
  timing the same reads are free. Composer metrics (2x
  getBoundingClientRect + documentElement style writes) rides the same
  fix.
- Same class, same fix at the remaining call sites profiling surfaced:
  ExpandableBlock and TerminalOutput (dozens per tool-heavy transcript)
  now measure/pin via RO initial delivery; the tool-window and
  thinking-preview pins drop their sync pin() call; the thread
  timeline's initial active-tick compute joins its existing
  scroll-time rAF batching so back-to-back transcript updates coalesce.
- thread/list: cut the render budget in the RENDER phase (state-from-
  props adjustment) instead of the post-commit layout effect. The
  effect-time cut was too late — on a warm switch React first built and
  committed the full 300-part tree, then re-rendered at 60, then bumped
  back to 300, so the expensive commit still happened (and on a cold
  switch the bump rAF usually fired while the transcript was still
  empty, so the prefetched messages rendered at full budget anyway).
  The render-phase cut restarts the component before any child renders;
  a second trigger handles the cold path where messages land later
  under the same sessionKey.
- thread/list: backfill 60 -> 300 inside startTransition so the older
  turns' markdown+shiki render is interruptible background work instead
  of a synchronous freeze one frame after the switch paints. Functional
  Math.max so an urgent "Show earlier" click can't be rebased back down.
- composer focus: skip the rAF/timeout focus retries when the element
  is already focused — focus() runs the full focusing steps (forcing
  layout) even on the active element, ~585ms per switch on a large
  dirty DOM.
- Replace the tautological render-budget test (it re-declared the
  constants locally and asserted 60 < 300) with behavior tests of the
  now-exported buildGroups + firstVisibleGroupIndex.

Verification: apps/desktop `npx tsc --noEmit` clean; full
`npx vitest run` 210 files / 1763 passed; manual CDP check confirms the
deferred backfill commits the full transcript, stays pinned to bottom,
and "Show earlier" still pages.
2026-07-16 22:46:08 -04:00
..
assistant-ui perf(desktop): kill the layout-thrash cascade on session switch (#66033) 2026-07-16 22:46:08 -04:00
chat perf(desktop): kill the layout-thrash cascade on session switch (#66033) 2026-07-16 22:46:08 -04:00
onboarding fmt(js): npm run fix on merge (#65229) 2026-07-15 21:40:56 +00:00
pane-shell fmt(js): npm run fix on merge (#65229) 2026-07-15 21:40:56 +00:00
particles feat(desktop): TikTok-style vibe hearts on a reusable particle system 2026-07-10 05:42:14 -05:00
pet chore(desktop): remove the DEV Shift+H heart preview 2026-07-10 16:09:23 -05:00
ui feat(desktop): button tooltip keybind hints + keybinds settings tab + unified worktree dialog (#65204) 2026-07-16 18:26:21 -04:00
Backdrop.tsx feat(desktop): add a chat backdrop on/off toggle 2026-07-14 16:50:03 -04:00
boot-failure-overlay.test.tsx fix(desktop): recover a failed gateway from the boot-failure screen 2026-07-12 04:07:41 -04:00
boot-failure-overlay.tsx fmt(js): npm run fix on merge (#65229) 2026-07-15 21:40:56 +00:00
boot-failure-reauth.test.ts fix(desktop): treat connected-but-expired remote sessions as reauth 2026-07-12 04:08:14 -04:00
boot-failure-reauth.ts fmt(js): npm run fix on merge (#65229) 2026-07-15 21:40:56 +00:00
brand-mark.tsx docs(desktop): add DESIGN.md design-system guide + close two consistency gaps (#40823) 2026-06-06 22:13:17 +00:00
desktop-install-overlay.tsx feat(desktop): ts-ify everything 2026-07-08 16:24:16 -07:00
error-boundary.tsx feat(desktop): add shared project UI primitives 2026-06-25 16:40:27 -05:00
gateway-connecting-overlay.test.tsx test(desktop): fix remaining act() warnings in gateway-connecting-overlay 2026-07-13 17:22:17 -04:00
gateway-connecting-overlay.tsx fmt(js): npm run fix on merge (#65229) 2026-07-15 21:40:56 +00:00
haptics-provider.tsx perf(desktop): faster session resume & warm AudioContext at idle 2026-06-12 21:07:40 -05:00
language-switcher.test.tsx Add searchable language picker 2026-06-06 07:51:44 -07:00
language-switcher.tsx feat(desktop): button tooltip keybind hints + keybinds settings tab + unified worktree dialog (#65204) 2026-07-16 18:26:21 -04:00
model-picker.tsx refactor(desktop): adopt shared utils + app-wide cleanups 2026-07-03 13:48:44 -05:00
model-visibility-dialog.tsx fix: limit desktop model pickers to explicit providers 2026-07-07 15:12:54 -07:00
notifications.tsx refactor(desktop): adopt shared utils + app-wide cleanups 2026-07-03 13:48:44 -05:00
page-loader.tsx Add Hermes desktop app (#20059) 2026-05-31 17:46:56 -05:00
prompt-overlays.test.tsx feat(desktop): shared UI — per-session prompt overlays, gateway overlays, tab primitives 2026-07-13 17:57:54 -04:00
prompt-overlays.tsx fmt(js): npm run fix on merge (#65229) 2026-07-15 21:40:56 +00:00
remote-display-banner.tsx refactor(desktop): adopt shared utils + app-wide cleanups 2026-07-03 13:48:44 -05:00
session-picker.tsx style(desktop,tui): fix all lint/type/formatting issues 2026-06-26 01:04:33 -05:00
status-dot.tsx Add Hermes desktop app (#20059) 2026-05-31 17:46:56 -05:00