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## Summary
The frontend was rerendering excessively across many interactions —
typing, clicking tools, opening modals, toggling the sidebar — because
**multiple compounding ref-instability cascades defeated `memo()` checks
in hot paths**. This PR fixes the cascades structurally.
Seven focused commits, low-to-high blast radius:
1. `perf(contexts): memoize BannerContext provider value`
2. `perf(contexts): memoize CommentAuthor and ActiveDocument provider
values`
3. `perf(contexts): memoize AppConfigContext provider value`
4. `perf(useToolManagement): stop spreading tool entries to keep refs
stable` — **root-cause fix**
5. `refactor(ToolPicker): hoist module-scope styles and helpers`
6. `feat(ToolWorkflowContext): add ref-stable Actions and Data subset
contexts` — additive
7. `perf(tools): migrate hot consumers to slim contexts and wrap in
memo()`
(Plus `style: apply prettier formatting` for CI.)
## What was wrong
Whenever something high-up in the tree caused a render, a chain of
unstable references propagated downward and forced every `ToolButton` to
re-execute its full body (hooks, derived computations, hook
subscriptions to other contexts). The chain:
- **4 unstable Context providers** (`Banner`, `CommentAuthor`,
`ActiveDocument`, `AppConfig`) were passing fresh `value={{ … }}`
objects on every render. Every consumer rerendered on every ancestor
render.
- **`useToolManagement.toolRegistry`** spread `{...baseTool, name,
description}` — a no-op spread that manufactured a new tool object
identity on every memo recompute.
- **The big `ToolWorkflowContext`** (25+ fields including
`state.searchQuery`) rebuilt its entire value on every
keystroke/click/toggle, forcing every `useToolWorkflow()` consumer (~36
files) to rerender.
- **`useToolNavigation`** transitively subscribed every `ToolButton` to
the full workflow context.
- **`ToolButton` & `ToolPicker`** weren't `memo()`-wrapped, so nothing
checked.
- **`ToolPanel`** passed inline `onSelect={(id) =>
handleToolSelect(...)}` — fresh ref every render, defeats child
memoization.
- **`ToolPicker`** allocated inline styles / `[]` / `toTitleCase` inside
the function body — churned `useToolSections`'s internal memo.
## Interaction matrix — what improves
The PR fixes the underlying ref-stability problem; the same fix benefits
*every* interaction that previously triggered the cascade:
| Interaction | Before | After |
|---|---|---|
| **Typing in tool search** | All visible buttons rerender per keystroke
| Only buttons whose matched-text changes rerender |
| **Clicking a tool** | All 36 `useToolWorkflow()` consumers rerender |
Only previously-selected and newly-selected buttons rerender (via
`isSelected` prop) |
| **Toggling sidebar / panel mode / reader mode** | Every tool button
rerenders | Tool components stay still (slim context doesn't see UI
state) |
| **Switching workbench / navigation** | `handleToolSelect` identity
changes → cascades through `onSelect` props | Ref-stabilized in Actions
context. Identity stable. Children's memo bails |
| **Modal/dialog open/close** | AppConfig churns → every `useAppConfig`
consumer rerenders (ToolButton reads `premiumEnabled`) | AppConfig
memoized; consumers rerender only when config changes |
| **Banner show/hide** | BannerProvider value churns → every consumer
rerenders on any ancestor render | Memoized; AppLayout rerenders only
when banner content changes |
| **Any state update high in the tree** | Compounding cascade defeats
memo everywhere | Stable subscriptions; memo bails out |
## Evidence
Per-keystroke prop instability on `ToolButton` (cleanest measurable
signal, captured via custom memo comparators logging which prop refs
differ):
| | `tool` ref diffs | `onSelect` ref diffs | `matchedSynonym` value
diffs | Total |
|---|---|---|---|---|
| Before | 18 | 18 | 6 | **42** |
| After | 0 | 0 | 6 | **6 (all legitimate)** |
→ **86% reduction** in spurious per-keystroke prop instability. The 6
remaining matched-synonym diffs are correct (different substring
highlighted per keystroke).
Context value rebuild counts during a keystroke (verified with
instrumented `useMemo` factories): `useToolWorkflowData=0`,
`useToolWorkflowActions=0`, `AppConfigContext=0`.
The same stabilization applies to click/toggle/modal interactions — they
were all driven by the same cascading invalidations.
## Honest caveat on render-count metrics
`React.Profiler` counts and function-body execution counts in **dev
mode** came back identical before vs after (StrictMode + concurrent
rendering + Mantine internal commits dominate the numbers). The PR's
value is measured against the **prop-stability signal** above, not
Profiler counts. Production builds — where StrictMode doesn't
double-render and Mantine internals aren't constantly committing — will
show memo bail out properly.
## Risk × benefit
| # | Commit | Risk | Benefit |
|---|--------|------|---------|
| 1 | BannerContext memo | ⬛ Trivial | 🟦 Small |
| 2 | CommentAuthor + ActiveDocument memo | ⬛ Trivial | 🟦 Small |
| 3 | AppConfig memo | ⬛ Trivial | 🟦 Moderate (wide consumer base) |
| 4 | useToolManagement spread removal | ⬛ Trivial | 🟥 **High (root
cause)** |
| 5 | ToolPicker hoist | ⬛ Trivial | 🟦 Small |
| 6 | ToolWorkflowContext split | 🟧 Low-Med | 🟥 **High (foundation)** |
| 7 | Hot consumer migration + memo | 🟧 Low-Med | 🟥 **High
(actualization)** |
Commit 6 introduces an invariant: ref-stabilized callbacks in the
Actions context must only be invoked from event handlers (post-commit),
never during render. All current call sites comply.
## Test plan
- [x] `npx playwright test --project=stubbed` — 145 / 6 skipped / 0
failed before and after.
- [x] Targeted regression: `main-dashboard`, `tool-search`, `navigation`
— 11/11 passing.
- [x] CI passing on commits (one infrastructure flake on
`docker-compose-tests` — "No space left on device" — unrelated;
rerunning).
- [ ] Manual sanity check in a dev build after merge.
## What this enables
The same Actions + Data subset-context pattern can be applied to
`FileContext`, `NavigationContext`, and other big contexts. The
foundation is in place.
Frontend
All frontend commands are run from the repository root using Task:
task frontend:dev— start Vite dev server (localhost:5173)task frontend:build— production buildtask frontend:test— run teststask frontend:test:watch— run tests in watch modetask frontend:lint— run ESLint + cycle detectiontask frontend:typecheck— run TypeScript type checkingtask frontend:check— run typecheck + lint + testtask frontend:install— install npm dependencies
For desktop app development, see the Tauri section below.
Environment Variables
Environment variables live in committed .env files at the frontend root:
.env— used by all builds (core, proprietary, and as the base for desktop/SaaS).env.desktop— additional vars loaded in desktop (Tauri) mode.env.saas— additional vars loaded in SaaS mode
These files contain non-secret defaults and are checked into Git, so most dev work needs no further setup.
To override values locally (API keys, machine-specific settings), create an uncommitted sibling .env.local / .env.desktop.local / .env.saas.local. Vite automatically layers these on top of the committed files.
Docker Setup
For Docker deployments and configuration, see the Docker README.
Tauri
All desktop tasks are available via Task. From the root of the repo:
Dev
task desktop:dev
This ensures the JLink runtime and backend JAR exist (skipping if already built), then starts Tauri in dev mode.
Build
task desktop:build
This does a full clean rebuild of the backend JAR and JLink runtime, then builds the Tauri app for production.
Platform-specific dev builds are also available:
task desktop:build:dev # No bundling
task desktop:build:dev:mac # macOS .app bundle
task desktop:build:dev:windows # Windows NSIS installer
task desktop:build:dev:linux # Linux AppImage
JLink Tasks
You can also run JLink steps individually:
task desktop:jlink # Build JAR + create JLink runtime
task desktop:jlink:jar # Build backend JAR only
task desktop:jlink:runtime # Create JLink custom JRE only
task desktop:jlink:clean # Remove JLink artifacts
Clean
task desktop:clean
Removes all desktop build artifacts including JLink runtime, bundled JARs, Cargo build, and dist/build directories.