Profiled with scripts/profile-tui.py under hold-PageUp + hold-wheel.
The placeholder → microtask-upgrade pattern did not reduce renderer
p99 (63ms → 63ms) or max (96ms → 142ms, slightly worse). Each fresh
row still pays the Md cost — just on a follow-up commit instead of
inline — and the follow-up commit shows up as a second heavy frame
a few ms later.
The real bottlenecks turned out to be:
1. wheel step too large (fixed in 7ca16eea)
2. outer terminal ANSI parse throughput (diagnosing next)
3. React commit frequency during hold-scroll (needs coalescing)
None of which DeferredMd addresses. Clearing the complexity so the
next experiments land on a simpler substrate.
Adds DeferredMd — a wrapper around <Md> that renders a lightweight
<Text> placeholder on first mount and upgrades to the full markdown
subtree on a queueMicrotask follow-up. Rationale: fresh MessageLine
mounts during PageUp hold run our markdown tokenizer + syntax
highlighter synchronously, producing the 63-112ms renderer spikes
profiled earlier. A plain <Text> placeholder only needs Yoga to wrap
the pre-stripped string (no tokenizer, no highlight), then the Md
subtree builds in a follow-up React commit.
Upgrade cache: once a (theme, compact, text) tuple has been upgraded,
a WeakMap-keyed Set remembers it so remounts (scroll-out then
scroll-back) mount straight into <Md> — no placeholder round-trip.
WeakMap on theme means palette swaps re-upgrade naturally.
Honesty note: profiling under hold-PageUp showed this didn't reduce
renderer p99 measurably — the upgrade commit just pays the Md cost on
a follow-up frame instead of inline. The bigger bottleneck turned out
to be React commit frequency (3.5 commits/sec during 30Hz scroll
input, with 200ms+ silent gaps between commits dominating perceived
FPS), which this change doesn't address. Keeping the deferred path
anyway because:
1. It's correct and tested — no regressions across 352 tests
2. Defensive for pathological fresh-mount cases (giant code blocks,
wide tables) that aren't in the current profile fixture
3. Pairs naturally with useVirtualHistory's useDeferredValue to keep
React's concurrent scheduler able to interrupt upgrade commits
If the follow-up perf investigation (terminal write throughput / patch
volume / commit frequency) shows DeferredMd is net-neutral-or-worse in
practice, this can be reverted with a one-line swap back to <Md> in
messageLine.tsx:115.
Companion to the streaming 2-column fix in 7242361a — these two
touched messageLine.tsx together so they land as a pair.
Split in-flight assistant text at the last stable block boundary so only
the unclosed tail re-tokenizes per stream delta. Previously the full
text was rendered as plain <Text> during streaming and only flipped to
<Md> at message.complete — cheap per delta but loses live markdown
formatting.
New StreamingMd component holds a monotonically-growing stablePrefix
in a ref (idempotent under StrictMode double-render), renders it as
one <Md> that memoizes across deltas, and renders the unstable suffix
as a second <Md> that re-parses on each delta. Cost per delta drops
from O(total length) to O(unstable length).
findStableBoundary walks back to the last "\n\n" outside an open
fenced code block — splitting inside an open fence would orphan the
opener and break highlighting in the prefix.
Adapted from claude-code's src/components/Markdown.tsx:186 but built
on our line-based tokenizer instead of marked.lexer. 9 new tests cover
fence balance, boundary walk, and empty input.
Part of the --tui perf audit (see audit #7).
- run the requested ui-tui lint+format pass and include resulting formatting updates
- guard text-measure cache eviction key in hermes-ink so ui-tui type-check stays green
Inline diff segments were anchored relative to assistant narration, but the
turn details pane still rendered after streamSegments. On completion that put
the diff before the tool telemetry that produced it. When a turn has anchored
diff segments, commit the accumulated thinking/tool trail as a pre-diff trail
message, then render the diff and final summary.
Round-2 Copilot review on #14968 caught two leftover spots that didn't
fully respect per-section overrides:
- messageLine.tsx (trail branch): the previous fix gated on
`SECTION_NAMES.some(...)`, which stayed true whenever any section was
visible. With `thinking: 'expanded'` as the new built-in default,
that meant `display.sections.tools: hidden` left an empty wrapper Box
alive for trail messages. Now gates on the actual content-bearing
sections for a trail message — `tools` OR `activity` — so a
tools-hidden config drops the wrapper cleanly.
- messageLine.tsx (showDetails): still keyed off the global
`detailsMode !== 'hidden'`, so per-section overrides like
`sections.thinking: expanded` couldn't escape global hidden for
assistant messages with reasoning + tool metadata. Recomputed via
resolved per-section modes (`thinkingMode`/`toolsMode`).
- types.ts: rewrote the SectionVisibility doc comment to reflect the
actual resolution order (explicit override → SECTION_DEFAULTS →
global), so the docstring stops claiming "missing keys fall back to
the global mode" when SECTION_DEFAULTS now layers in between.
All three lookups (thinking/tools/activity) are computed once at the
top of MessageLine and shared by every branch.
Copilot review on #14968 caught that the early returns gated on the
global `detailsMode === 'hidden'` short-circuited every render path
before sectionMode() got a chance to apply per-section overrides — so
`details_mode: hidden` + `sections.tools: expanded` was silently a no-op.
Three call sites had the same bug shape; all now key off the resolved
section modes:
- ToolTrail: replace the `detailsMode === 'hidden'` early return with
an `allHidden = every section resolved to hidden` check. When that's
true, fall back to the floating-alert backstop (errors/warnings) so
quiet-mode users aren't blind to ambient failures, and update the
comment block to match the actual condition.
- messageLine.tsx: drop the same `detailsMode === 'hidden'` pre-check
on `msg.kind === 'trail'`; only skip rendering the wrapper when every
section resolves to hidden (`SECTION_NAMES.some(...) !== 'hidden'`).
- useMainApp.ts: rebuild `showProgressArea` around `anyPanelVisible`
instead of branching on the global mode. This also fixes the
suppressed Copilot concern about an empty wrapper Box rendering above
the streaming area when ToolTrail returns null.
Regression test in details.test.ts pins the override-escapes-hidden
behaviour for tools/thinking/activity. 271/271 vitest, lints clean.
Visual polish on top of the segment-anchor change: diff blocks were
butting up against the narration around them. Tag diff-only segments
with `kind: 'diff'` (extended on Msg) and give them `marginTop={1}` +
`marginBottom={1}` in MessageLine, matching the spacing we already
use for user messages. Also swaps the regex-based `diffSegmentBody`
check for an explicit `kind === 'diff'` guard so the dedupe path is
clearer.
- /retry: use session['history'] instead of non-existent
agent.conversation_history; truncate history at last user message
to match CLI retry_last() behavior; add history_lock safety
- /plan: pass user instruction (arg) to build_plan_path instead of
session_key; add runtime_note so agent knows where to save the plan
- ANSI tool results: render full text via <Ansi wrap=truncate-end>
instead of slicing raw ANSI through compactPreview (which cuts
mid-escape-sequence producing garbled output)
- Move _PENDING_INPUT_COMMANDS frozenset to module level
- Use get_skill_commands() (cached) instead of scan_skill_commands()
(rescans disk) in slash.exec skill interception
- Add 3 retry tests: happy path with history truncation verification,
empty history error, multipart content extraction
- Update test mock target from scan_skill_commands to get_skill_commands
Additional TUI fixes discovered in the same audit:
1. /plan slash command was silently lost — process_command() queues the
plan skill invocation onto _pending_input which nobody reads in the
slash worker subprocess. Now intercepted in slash.exec and routed
through command.dispatch with a new 'send' dispatch type.
Same interception added for /retry, /queue, /steer as safety nets
(these already have correct TUI-local handlers in core.ts, but the
server-side guard prevents regressions if the local handler is
bypassed).
2. Tool results were stripping ANSI escape codes — the messageLine
component used stripAnsi() + plain <Text> for tool role messages,
losing all color/styling from terminal, search_files, etc. Now
uses <Ansi> component (already imported) when ANSI is detected.
3. Terminal tab title now shows model + busy status via useTerminalTitle
hook from @hermes/ink (was never used). Users can identify Hermes
tabs and see at a glance whether the agent is busy or ready.
4. Added 'send' variant to CommandDispatchResponse type + asCommandDispatch
parser + createSlashHandler handler for commands that need to inject
a message into the conversation (plan, queue fallback, steer fallback).
Hoist turn state from a 286-line hook into $turnState atom + turnController
singleton. createGatewayEventHandler becomes a typed dispatch over the
controller; its ctx shrinks from 30 fields to 5. Event-handler refs and 16
threaded actions are gone.
Fold three createSlash*Handler factories into a data-driven SlashCommand[]
registry under slash/commands/{core,session,ops}.ts. Aliases are data;
findSlashCommand does name+alias lookup. Shared guarded/guardedErr combinator
in slash/guarded.ts.
Split constants.ts + app/helpers.ts into config/ (timing/limits/env),
content/ (faces/placeholders/hotkeys/verbs/charms/fortunes), domain/ (roles/
details/messages/paths/slash/viewport/usage), protocol/ (interpolation/paste).
Type every RPC response in gatewayTypes.ts (26 new interfaces); drop all
`(r: any)` across slash + main app.
Shrink useMainApp from 1216 -> 646 lines by extracting useSessionLifecycle,
useSubmission, useConfigSync. Add <Fg> themed primitive and strip ~50
`as any` color casts.
Tests: 50 passing. Build + type-check clean.
