Nitro-V3/docs/ARCHITECTURE.md

Architecture & Refactor Plan

Status: living document, last updated 2026-05-10. This file describes the structural direction the codebase is moving in. Read it before starting a non-trivial refactor — half the value comes from staying consistent, not from each individual change.

Table of contents

1. Where the project stands today
2. Five structural improvements
   1. Event subscriptions as derived state
   2. Server requests as queries
   3. Feature folders
   4. Splitting god-hooks
   5. Unified UI store
3. Bonus: error boundaries
4. What's already in place
5. How to pick the next refactor PR

---

Where the project stands today

The codebase is a React 19.2 client for the Nitro renderer (Habbo-style hotel client). Most of the architectural pressure comes from the renderer's event-bus + composer/parser model: the UI talks to the server by sending composers and listening to incoming message events. Almost every piece of state in this app is "the latest value seen on a given event".

That model creates two kinds of friction with modern React:

1. useEffect everywhere — react-hooks/set-state-in-effect reports ~328 violations across ~280 files. Most are legitimate event-driven updates, but the pattern hides the intent (it reads as "imperative setState on mount/effect" rather than "subscribe to a stream").
2. God-hooks — useCatalog (~1100 lines), useChat, useWiredTools, useInventoryFurni all bundle data fetching, UI state, side effects, and computed values into a single export. Components import the whole thing for one field; the React Compiler skips memoization.

Two big files (WiredCreatorToolsView.tsx 4493→3901 lines, LoginView.tsx 1700) further compound the problem: the Compiler logs "Compilation Skipped: Existing memoization could not be preserved", which means manual useMemo/useCallback are not even helping.

The improvements below are ordered so that each one makes the next one easier.

---

Five structural improvements

1. Event subscriptions as derived state

Problem. Pattern repeated hundreds of times:

const [foo, setFoo] = useState(initial);
useNitroEvent(SomeEvent, e => setFoo(e.payload));

or with the message channel:

const [data, setData] = useState(null);
useMessageEvent(SomeParser, e => {
    const parser = e.getParser();
    if (!parser) return;
    setData(parser.field);
});

The shape of the code obscures the intent ("foo IS the latest event payload") and makes the lint think we're doing imperative setState in an effect.

Solution. Two thin hooks (src/hooks/events/useNitroEventState.ts and useMessageEventState.ts):

const foo = useNitroEventState(SomeEvent, e => e.payload, initial);
const data = useMessageEventState(SomeParser, e => e.getParser()?.field ?? null, null);

Internally the selector closure is held in a ref refreshed in commit phase (useLayoutEffect), so a new selector identity per render does not force re-subscription. The listener is registered once.

Status. Implemented + adopted in OfferView.tsx, useAvatarInfoWidget (figure/badges/group merge), and useInventoryFurni (extracted pure reducers consumed by useMessageEvent setters).

Adoption. Organic: when a contributor sees a clean "derive-from-single-event" case, they convert it. Do not sweep-replace. The majority of existing subscriptions have side effects, multi-state updates, conditional filters, or state-machine semantics that lose information when forced into a single selector.

Companions (all implemented in src/hooks/events/):

• useNitroEventReducer<S, T>(types, reducer, initial) — multiple event types collapsing into one owned state slice (analogous to useReducer but driven by renderer events).
• useMessageEventReducer<S, T>(eventTypes, reducer, initial) — same shape on the server message channel; accepts a single type or an array of types that all feed the same reducer.
• useExternalSnapshot<T>(subscribe, getSnapshot) — useSyncExternalStore wrapper pairing the renderer's EventDispatcher.subscribe() with the getXxxSnapshot() getters added in renderer 2.1.0. Use this for readonly views over manager state (getUserDataSnapshot, getActiveRoomSessionSnapshot).

For state owned outside the listener (the useState + setState(prev => applyX(prev, event)) pattern), keep using useNitroEvent / useMessageEvent and extract the reducer as a pure function for testability. See src/hooks/inventory/useInventoryFurni.reducers.ts and src/hooks/rooms/widgets/avatarInfo.reducers.ts for the convention.

---

2. Server requests as queries

Problem. A request/response pair against the server today looks like:

useEffect(() => {
    SendMessageComposer(new GetXComposer());
}, []);

useMessageEvent(YParser, e => {
    setData(e.getParser().data);
});

There is no caching, no deduplication, no retry, no loading or error state, no devtools. Every consumer rolls its own. The same request fires multiple times if multiple components mount it.

Solution. Wrap composer/parser pairs in a TanStack Query adapter (@tanstack/react-query is in the same family as @tanstack/react-virtual which is already a dependency):

const { data, isLoading } = useNitroQuery({
    request: () => new GetXComposer(),
    parser: YParser,
    select: e => e.getParser().data,
});

Status. Adapter prototype written (src/api/nitro-query/createNitroQuery.ts). Not wired up because @tanstack/react-query is not yet installed — deliberately left as a yarn add step the team can approve.

To enable.

yarn add @tanstack/react-query @tanstack/react-query-devtools

Then mount the provider in src/index.tsx:

<QueryClientProvider client={queryClient}>
    <App />
    <ReactQueryDevtools initialIsOpen={false} />
</QueryClientProvider>

Migration order suggested.

1. Read-only catalog data (useCatalog page fetches) — biggest win, lowest risk because it's mostly read.
2. Inventory tabs.
3. Navigator search results.
4. Marketplace listings.

Push messages (events the server emits without the client asking) keep using useMessageEventState — they're not requests.

---

3. Feature folders (adopted) — rejected, keep the current layout

Update: an earlier version of this document proposed a src/features/<feature>/ layout (vertical slices). The pilot on the doorbell widget showed that the existing src/components/<area>/ + src/hooks/<area>/ split is the convention the team wants to keep. The pilot has been rolled back; this section is left as a record of the decision.

Current convention (the one to follow):

• Views live under src/components/<area>/<feature>/*.tsx (e.g. src/components/room/widgets/doorbell/DoorbellWidgetView.tsx).
• Hooks live under src/hooks/<area>/<feature?>/*.ts (e.g. src/hooks/rooms/widgets/useDoorbellState.ts). Multiple hooks for the same widget go in the same folder as siblings, not in a per-widget subfolder.
• Pure helpers / constants / types that are specific to one view go in sibling files next to the view (see src/components/wired-tools/WiredCreatorTools.{types,constants,helpers}.ts for the established pattern).
• Cross-cutting utilities continue to live under src/api/ and src/common/.

Discoverability is acceptable as long as the naming is consistent — useDoorbellState / useDoorbellActions / DoorbellWidgetView are greppable in seconds even though they live in three separate directory trees.

---

4. Splitting god-hooks

Problem. useCatalog.ts is ~1100 lines. It owns:

• Server fetch lifecycle (request/parser pairs)
• UI state (selected page, current product, filters)
• Side effects (purchases, gift composer dispatch)
• Computed values (pricing display, page tree)
• Cross-cutting helpers (currency lookup, club level checks)

Every component that imports useCatalog() for one field re-runs the whole thing. The Compiler can't memoize it (too large). Tests can't be written against a single concern.

Solution. Split by responsibility, not by entity:

useCatalogData()      // server data, returns { pages, currentPage, isLoading }
useCatalogUiState()   // ui state, returns { selectedNode, setSelectedNode, filters, ... }
useCatalogActions()   // imperative actions, returns { purchase, gift, openOffer }

Inside, useCatalogData uses useNitroQuery (#2). useCatalogUiState uses a Zustand slice (#5). useCatalogActions is a stateless export — just functions that compose composers.

Status. Pilot done on useDoorbellWidget:

• src/hooks/rooms/widgets/useDoorbellState.ts — the users list, derived from three events using a useNitroEventReducer-like pattern.
• src/hooks/rooms/widgets/useDoorbellActions.ts — answer(name, flag).
• src/hooks/rooms/widgets/useDoorbellWidget.ts kept as a deprecated shim that composes the two so existing consumers don't break.

It's a small hook so the split looks almost theatrical, but the shape is the same one we want to apply to useCatalog.

Migration order suggested. Largest pain first, moving down:

1. useCatalog (~1100 LOC) — but only after #2 is enabled (server fetches collapse to a few useNitroQuery calls, removing 60% of the file).
2. useChatInputWidget (~500 LOC)
3. useWiredTools (~600 LOC)
4. useInventoryFurni (~300 LOC)

---

5. Unified UI store

Problem. Cross-feature UI state lives in:

• React Context (e.g. UiSettingsContext)
• Custom hooks with module-level singletons (useNavigator's implicit cache)
• let foo = ... module-level mutable variables — flagged by the React Compiler as "Writing to a variable defined outside a component or hook is not allowed" (currently 5+ violations)
• localStorage reads in effects

There is no single source of truth, no devtools, no time-travel.

Solution. Adopt Zustand for cross-feature UI state. Each feature owns one slice:

// src/state/wired-tools.ts (or src/components/wired-tools/wiredToolsStore.ts)
export const useWiredToolsStore = create<WiredToolsState>()((set) => ({
    activeTab: 'monitor',
    setActiveTab: (tab) => set({ activeTab: tab }),
    // ...
}));

Components subscribe to specific keys (Zustand re-renders only the subscribers whose selected slice changed):

const activeTab = useWiredToolsStore(s => s.activeTab);

This eliminates the let isCreatingRoom = false module-level pattern and makes the state ispezionable in dev tools.

Status. Skeleton written (src/state/createNitroStore.ts), not yet adopted — zustand is not yet installed. Same reason as #2: deliberately a follow-up yarn add step.

To enable.

yarn add zustand

Then convert the smallest singleton first (suggestion: the isCreatingRoom/createRoomTimeout pair in NavigatorRoomCreatorView.tsx — it's a clean 5-line conversion).

Do not wholesale-replace Context. Some Contexts (theming, i18n) are fine as-is. Zustand is for application state, not configuration state.

---

Bonus: error boundaries

react-error-boundary is already a dependency. A widget crashing in a room (e.g. malformed pet data in InfoStandWidgetFurniView) currently takes down the whole UI.

Solution. Wrap each widget root in <ErrorBoundary fallback={null} onError={NitroLogger.error}>. Implementation lives at src/common/error-boundary/WidgetErrorBoundary.tsx.

Status. Implemented + applied to RoomWidgetsView as the umbrella for all in-room widgets, plus a per-widget pass that wraps each of the 13 direct children of RoomWidgetsView and each of the 20 sub-widgets in FurnitureWidgetsView. A crash in any single widget now silently logs through NitroLogger and renders null for that widget only — its siblings keep rendering. Each boundary carries a name prop matching the widget so the log line identifies the culprit.

---

What's already in place

The current branch (feat/react19-modernization, PR #2) has applied:

Toolchain

• React 19.2 / react-dom 19.2 / @types/react 19.2.
• TS 6 for build + TS 7 native preview (tsgo) for yarn typecheck.
• ESLint 10 + typescript-eslint 8 + eslint-plugin-react-hooks@7 + eslint-plugin-react-compiler.
• Vite 8 + React Compiler 1.0 (babel-plugin-react-compiler).
• <StrictMode> mounted; App.tsx made idempotent for the double-mount.

React 19 idioms

• forwardRef → ref prop on 7 layout/component files (11 call sites).
• <Ctx.Provider> → <Ctx> on 6 contexts.
• Native <script> in TurnstileWidget, ExternalPluginLoader, GoogleAdsView.
• Form Actions (useActionState + useFormStatus) for the inline Login/Register/Forgot dialogs in LoginView.tsx. Legacy non-Action versions in components/login/components/ removed as dead code.
• useEffectEvent in App.tsx, FurniEditorSearchView, NotificationBadgeReceivedBubbleView, NavigatorRoomSettingsRightsTabView, UiSettingsContext, TurnstileWidget — clears all remaining exhaustive-deps warnings.
• Targeted set-state-in-effect fixes: CatalogHeaderView (pure derive), NavigatorRoomCreatorView (lazy state init), LoginView (track-previous-prop reset), ChooserWidgetView (callback in useEffectEvent).

Patterns + adoption (proposals #1, #2, #4, #5)

• useNitroEventState / useMessageEventState + companions (proposal #1) — adapters in src/hooks/events/. Selectors are held in a useLayoutEffect-refreshed ref (Dan Abramov's use-event-callback pattern) so the listener stays mounted across renders. Companions for the multi-event → single state-slice case: useNitroEventReducer, useMessageEventReducer, plus useExternalSnapshot (a typed wrapper of useSyncExternalStore for the renderer's EventDispatcher.subscribe() + getXxxSnapshot() getters added in Nitro_Render_V3 2.1.0). Pilots: OfferView (single-event), useAvatarInfoWidget (3 listeners for figure/badges/group merged via pure reducers — moved out of InfoStandWidgetUserView, killing 3 CloneObject calls), and useInventoryFurni (4 message listeners + fragment buffer refactored to pure reducers; the module-level furniMsgFragments is now a useRef and the dead FurniturePostItPlacedEvent handler dropped).
• useNitroQuery (proposal #2) — enabled. @tanstack/react-query + devtools installed; QueryClientProvider mounted in src/index.tsx. Adapter at src/api/nitro-query/createNitroQuery.ts with select, accept (correlation-key filter), timeoutMs, staleTime, plus a lower-level awaitNitroResponse() for imperative use. Companion at src/api/nitro-query/useNitroEventInvalidator.ts invalidates a slot whenever the server pushes the matching event unprompted — required for queries whose data the server refreshes outside the request cycle (e.g. ClubGiftInfoEvent after a gift claim). Pilots / sites:
  • OfferView (targeted offer)
  • CatalogLayoutRoomAdsView (room-ad list)
  • ModToolsChatlogView / CfhChatlogView (correlated by roomId / ticketId)
  • useGiftConfiguration — replaces the GiftWrappingConfigurationEvent listener + eager composer dispatch that lived in useCatalog
  • useUserGroups — consolidates 5 sites that each fired CatalogGroupsComposer independently (2 wired views + 2 catalog group widgets + useCatalog itself); now one query, dedup'd
  • useClubOffers(windowId) — per-windowId query for the VIP / Builders Club purchase pages, with accept() correlation filter
  • useSellablePetPalette(breed) — per-breed pet palette, accept() filter on parser.productCode
  • useMarketplaceConfiguration — lifts a self-fetch out of MarketplacePostOfferView
  • useClubGifts — paired with useNitroEventInvalidator for the server-push-after-SelectClubGift case
• ICatalogOptions deleted — useCatalog used to expose a catalogOptions bag where multiple components stuffed unrelated fetched data (groups, clubOffers, clubOffersByWindowId, petPalettes, marketplaceConfiguration, clubGifts, giftConfiguration). Every field is now its own TanStack query at the consumer site; the bag and the interface are gone.
• Layout / feature folders (proposal #3) — rejected. The existing src/components/<area>/<feature>/ (views) + src/hooks/<area>/<feature?>/ (flat hook files) is the layout that stays. See section 3 above for the full rule.
• God-hook split (proposal #4) — applied to:
  • doorbell: useDoorbellState + useDoorbellActions + shim.
  • poll: usePollSubscriptions (mounted once in RoomWidgetsView)
    • usePollActions + shim. useWordQuizWidget was migrated to import usePollActions directly so it doesn't pull subscriptions.
  • furni chooser: useFurniChooserState + useFurniChooserActions
    • shim. Helper buildWallItem/buildFloorItem dedupes ~50 lines of inline RoomObjectItem construction (typed via IRoomObject; the dead sessionDataManager.getUserData fallback dropped — the method never existed).
  • user chooser: useUserChooserState + useUserChooserActions
    • shim. Helper buildUserItem. Adds ?. guards on roomSession?.userDataManager? to avoid the room-transition NPE pattern.
  • friend request: useFriendRequestState (3 useState + 2 event bridges + 1 derive effect) + useFriendRequestActions (thin adapter on the friends store) + shim. Exports ActiveFriendRequest type.
  • chat input: useChatInputState (5 state slices + 3 event listeners + 3 lifecycle effects: flood countdown, idle auto-clear, typing-indicator sync) + useChatInputActions (sendChat with the full slash-command repertoire and the outgoing-translation pipeline) + shim. Single consumer (ChatInputView) keeps the original tuple.
  • wired tools: useWiredToolsStore (internal singleton — state, listeners, effects, 13 actions in one closure) + useWiredToolsState / useWiredToolsActions (read-only and imperative useBetween filters over the same singleton) + useWiredTools shim. Used by ~20 consumers; the singleton sharing keeps a single source of truth while letting consumers import only the slice they touch.
  • translation: useTranslationStore (internal singleton) + useTranslationState / useTranslationActions (filtered useBetween views) + useTranslation shim. Same pattern as Wired tools — six consumers split across read-only views (settings panel, bootstrap) and dispatch sites (messenger, chat input).
  • notification: useNotificationStore (internal singleton) + useNotificationState (queue arrays for the renderer view) + useNotificationActions (8 entry points: simpleAlert, showNitroAlert, showTradeAlert, showConfirm, showSingleBubble, closeAlert, closeBubbleAlert, closeConfirm) + shim. The ~30 message-event listeners and 5 state slices stay in the singleton. Used by ~44 consumers, most of which only need one action.
  • friends: useFriendsStore (internal singleton) + useFriendsState (friends arrays, settings, derived online/offline split, lookup helpers) + useFriendsActions (requestFriend, requestResponse, followFriend, updateRelationship)
    • shim. 16 consumers.
• Zustand (proposal #5) — enabled. zustand installed; factory at src/state/createNitroStore.ts. First adoption: the let isCreatingRoom / createRoomTimeout module-level pair in NavigatorRoomCreatorView replaced by useRoomCreatorStore (timer lives in the store closure, survives StrictMode double-mount).

WiredCreatorToolsView decomposition

• Top-level constants/types/helpers extracted to sibling files (WiredCreatorTools.{types,constants,helpers}.ts).
• All four tab JSX bodies extracted into sibling components:
  • WiredMonitorTabView
  • WiredInspectionTabView
  • WiredVariablesTabView
  • WiredToolsSettingsTabView (already separate from before this PR)
• The three Monitor-tab overlay popups guarded by { false && ... } were dead duplicates of the live overlays mounted at the root level — dropped.
• Main view: 4493 → 3544 lines (−21%).

useCatalog decomposition (in progress)

The 1100-line god-hook owns the catalog page tree, current page, offer selection, and a long tail of secondary fetches. Decomposition strategy from ARCHITECTURE.md proposal #4 step 1: lift the session-stable read-only fetches to TanStack queries first, then split the remaining state ownership into useCatalogData / useCatalogUiState / useCatalogActions.

Status after this round of work:

Fetch	Migrated to
GiftWrappingConfiguration	useGiftConfiguration()
GuildMemberships	useUserGroups()
HabboClubOffers (per windowId)	useClubOffers(windowId)
SellablePetPalettes (per breed)	useSellablePetPalette(breed)
MarketplaceConfiguration	useMarketplaceConfiguration()
ClubGiftInfo	useClubGifts() (with useNitroEventInvalidator)
CatalogPagesList / CatalogPage	deferred — core state slice (rootNode / offersToNodes / currentPage), needs its own split-out store
BuildersClubFurniCount / SubscriptionStatus	deferred — read by the internal getBuilderFurniPlaceableStatus logic, moves with the data/actions split

Helper extraction + filter split both landed. The 1100-line hook now has its dependency-free logic in src/hooks/catalog/useCatalog.helpers.ts and exposes three public filters built on top of the same useBetween singleton:

• useCatalogData() — server-driven read-only slice (rootNode, offersToNodes, currentPage, currentOffer, frontPageItems, searchResult, roomPreviewer, isBusy, catalogLocalizationVersion, Builders Club counters + timers).
• useCatalogUiState() — UI ephemeral state + writers (isVisible, pageId, previousPageId, currentType, activeNodes, navigationHidden, purchaseOptions, catalogPlaceMultipleObjects, plus all the set* writers, including the ones that mutate the data slice on page / offer / search-result selection).
• useCatalogActions() — imperative operations (openCatalogByType, toggleCatalogByType, activateNode, openPageBy{Id,Name,OfferId}, requestOfferToMover, selectCatalogOffer, getNodeBy{Id,Name}, getBuilderFurniPlaceableStatus).

The internal store is named useCatalogStore and is not exported; the three public entry points (useCatalogData / useCatalogUiState / useCatalogActions) all funnel into the same useBetween instance, so listeners + state register once. All 48 historical consumers have been migrated to the targeted filters; the deprecated useCatalog shim has been removed.

Pure helpers in useCatalog.helpers.ts:

• normalizeCatalogType(type?) — coerce the optional catalog type back to NORMAL / BUILDER.
• getOfferProductKeys(offer) — canonical lookup keys for the resolved-offer cache.
• findNodeById / findNodeByName — DFS over the catalog tree, root excluded.
• getNodesByOfferIdFromMap(offerId, map, onlyVisible) — used to be the closed-over getNodesByOfferId; the onlyVisible fallback to the full bucket is preserved.
• buildCatalogNodeTree(NodeData) — pulled out of the CatalogPagesListEvent reducer; returns the tree + the offerId index map in one pass.
• resolveBuilderFurniPlaceableStatus(input) — the placement decision tree as a pure function; the hook keeps the GetRoomEngine / GetSessionDataManager reads (to count non-self, non-moderator visitors) and passes the resulting visitorCount into the helper.

useCatalog.ts now imports these instead of defining them inline (net −75 LOC). Test file tests/useCatalog.helpers.test.ts covers all six helpers with 34 cases (tree depth + offerId mapping, node lookups including root exclusion, the limit-reached / guild-admin fallback / visitors-in-room paths of the placement helper, and the empty-map / partial-bucket branches of the offer lookup).

Tests

• Vitest 3 + jsdom + @testing-library/react + @testing-library/jest-dom configured. Separate vitest.config.mts so the runner doesn't drag in the renderer SDK aliases from vite.config.mjs.

• 163 cases passing across 12 test files. Pure-module suites:

  • WiredCreatorTools.helpers.test.ts (18) — formatters + snapshot factory.
  • navigatorRoomCreatorStore.test.ts (4) — Zustand store invariants with fake timers.
  • api-utils.test.ts (27) — ConvertSeconds, LocalizeShortNumber, CloneObject, GetWiredTimeLocale, WiredDateToString, PrefixUtils.
  • api-utils-extra.test.ts (16) — ColorUtils, FixedSizeStack, LocalizeFormattedNumber.
  • friendly-time.test.ts (12) — FriendlyTime with a deterministic LocalizeText mock (cuts the transitive renderer-SDK import).
  • dedupeBadges.test.ts (6) — slot-preserving badge dedup (covers the helper used by the InfoStand pilot).
  • catalog-favorites.helpers.test.ts (16) — localStorage parse + v2→v3 migration + per-catalog-type storage-key routing.
  • avatar-info-reducers.test.ts (14) — InfoStand reducer pilot: bail-out branches (state-not-AvatarInfoUser, mismatched user/roomIndex, equal-after-dedup) + the figure / favorite-group apply paths.
  • useCatalog.helpers.test.ts (34) — catalog pure helpers extracted out of the god-hook: normalizeCatalogType, getOfferProductKeys, findNodeById / findNodeByName (with the root-exclusion guard), getNodesByOfferIdFromMap (with the partial-visible fallback), buildCatalogNodeTree (tree depth + offerId index), and the full decision tree of resolveBuilderFurniPlaceableStatus.
  • useCatalog.filters.test.tsx (4) — contract tests for the three-way singleton-filter split. Stubs use-between so the filters share one fake store, asserts each filter exposes exactly the keys it owns (no leak across slices), and pins down === identity of callbacks between the shim and each slice so the migration of the 48 consumers stays safe.

  Component-/hook-level suites (on the new renderer-SDK mock):

  • WidgetErrorBoundary.test.tsx (4) — happy path + caught render error logged via NitroLogger.error + custom fallback + unknown default name.
  • useDoorbellState.test.tsx (7) — initial empty state, append on DOORBELL, dedup duplicates, remove on RSDE_ACCEPTED / RSDE_REJECTED, ignore stale events, unsubscribe on unmount.

• Renderer-SDK mock at tests/mocks/renderer-mock.ts — vitest.config.mts aliases @nitrots/nitro-renderer over this file so jsdom-hosted tests never load Pixi or the message parser/composer registry. The mock exports:

  • Explicit, behavioral stubs for the symbols tests actually exercise: NitroLogger, GetEventDispatcher, mockEventDispatcher / clearMockEventDispatcher helpers, the RoomSessionDoorbellEvent class (signature mirrors the real (type, session, userName) so tsgo stays happy).
  • String-keyed Proxy enums for every *EventType / *FigurePartType / RoomObjectCategory etc. — each access returns a stable unique string so dispatch + listener agree.
  • Lightweight class StubClass {} placeholders for the ~30 Pixi and gameplay classes the src/api/* barrel touches at import time (NitroAlphaFilter, NitroContainer, EventDispatcher, etc.). Keeps the cascade from throwing without simulating behavior tests don't care about.
  • Singleton getters (GetAssetManager, GetCommunication, GetSessionDataManager, …) returning a chainable proxy so GetX().y.z evaluates to a no-op proxy instead of crashing.

• Pure-module convention (still applies for non-component tests): import from concrete file paths so jsdom doesn't transitively load the renderer SDK; use import type { … } for type-only renderer imports.

• yarn test + yarn test:watch scripts.

Logic bug fixes

• Doorbell close button didn't close while users were pending (useEffect(() => setIsVisible(!!users.length)) overrode the close).
• Doorbell answer() removed users locally before the server confirmed via RSDE_ACCEPTED/RSDE_REJECTED, desyncing on network drop.
• RoomToolsWidgetView wiped nitro.room.history from localStorage on every beforeunload (every tab close).
• AvatarInfoPetTrainingPanelView crashed if roomSession was null at parser time.
• useInventoryFurni had a module-level furniMsgFragments buffer that would have collided between two simultaneous client instances (now scoped to a useRef inside the singleton hook).

Dead code removed

• src/components/login/components/RegisterDialog.tsx.
• src/components/login/components/ForgotDialog.tsx.
• src/components/login/components/shared.ts (consumed only by the two legacy dialogs).
• useInventoryFurni's empty FurniturePostItPlacedEvent handler.
• IRoomSession.sendWhisperGroupMessage + impl in the renderer (the ChatWhisperGroupComposer it referenced never existed; no client call site).

Typecheck baseline

• Repository-wide tsgo (TS 7 preview) errors driven down to 0 client-side and 0 renderer-side via a series of small targeted sweeps:
  • Framer-motion Variants typing on ToolbarView + FriendsBarView (−33).
  • createNitroQuery import path / generics / Pick subset (−3 + −1 propagation).
  • useFurniChooserState typed as IRoomObject + dead getUserData branch dropped (−10).
  • ColorVariantType extended with the 5 outline-* bootstrap variants used by the group-forum thread view (−4).
  • React 19 JSX import in WiredNeighborhoodSelectorView (−1).
  • showConfirm extra-arg drop in useOnClickChat (−1).
  • UserContainerView friendsCount.toString() (−1).
• Renderer-side cluster cleared in a single pass: TS 5.7+ ArrayBuffer drift, Pixi v8 Filter[] / WebGLRenderer narrows, missing IGraphicAsset import, empty-tuple IMessageComposer<[]>, PetBreedingMessageParser.bytesAvailable boolean-vs-number bug, RoomEnterComposer extended with optional spawnX/spawnY to match the Arcturus server (which already reads both ints when present).

Bonus

• WidgetErrorBoundary (src/common/error-boundary/) — wraps the RoomWidgetsView umbrella. A widget crash now degrades gracefully (logged to NitroLogger.error) instead of unmounting the room.
• CLAUDE.md at the repo root — onboarding file Claude Code reads at session start. Captures the layout convention, the patterns to use, what's wired up, what isn't, and the open logic bugs.

Boot-time orchestration (src/bootstrap.ts)

• Mobile viewport meta tag inserted before anything else.
• await loadClientMode() — fetches client-mode.json into window.__nitroClientMode so getClientMode() can pick up secureAssetsEnabled / secureApiEnabled / apiBaseUrl for the fetch interceptor.
• installSecureFetch() (no-op when both secureAssetsEnabled and secureApiEnabled are off, which is the dev default).
• Populate window.NitroConfig with config.urls, sso.ticket, forward parameters.
• await GetConfiguration().init() — eager configuration load before React mounts. Eliminates the "Missing configuration key: asset.url / login.endpoint / login.turnstile.* / …" warning flood that happens when components synchronously read keys on the first paint while prepare()'s deferred init is still in flight.
• import('./index') — dynamic, so we keep top-level await for the steps above.

Dev asset serving (vite.config.mjs)

• Game asset directories (bundled/, c_images/, gamedata/, swf/) live OUTSIDE the repo. The historical "symlink them into public/ so Vite serves them via publicDir" trick is a trap on Windows: chokidar tries to install a watcher on every file under public/ and the dev server hangs for minutes on ~177k assets.
• The current setup installs a tiny Vite plugin (nitroAssetsServer) that mounts sirv on /nitro-assets and /swf, reading from ../Nitro-Files/{nitro-assets,swf}. sirv is connect-style middleware; it bypasses chokidar entirely.
• The same plugin wires the same handler into configurePreviewServer so yarn preview keeps working with the production build.
• .gitignore has explicit entries for /public/nitro-assets and /public/swf plus a comment explaining why those paths must not be recreated as symlinks.

Upstream feature catch-up

• duckietm/Nitro-V3 PR #126 is cherry-picked: adds src/components/user-settings/UserAccountSettingsView.tsx (reset password / email / change username flows under the user settings overlay) and a wear-badge popup fix in NotificationBadgeReceivedBubbleView that gates the button on the canShowWearButton derived predicate. The cherry-pick required reconciling the LoginView fork to the Form Actions migration (useActionState + useFormStatus) and restoring the useEffectEvent-wrapped subscription pattern used elsewhere in this branch.

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How to pick the next refactor PR

Foundations are done: React Query enabled with 4 pilot migrations, Zustand enabled with 1 store, Vitest with 77 cases, error boundary on the room widgets umbrella, usePollSubscriptions already hoisted to RoomWidgetsView, WiredCreatorToolsView fully split per tab.

Remaining order of value/risk for the next contributor:

1. Migrate useCatalog's read-only fetches to useNitroQuery. Biggest expected payoff (cache + dedup + loading state for free). The hook is ~1100 lines; start with the page-tree fetch and the handful of fire-and-forget request/response pairs (gift wrapping config, builders-club furni count, sellable pet palettes). The imperative purchase / gift flows stay where they are. Add a Vitest case per migration.
2. Split useCatalog along the doorbell/poll lines (useCatalogData / useCatalogUiState / useCatalogActions, siblings under src/hooks/catalog/). Only after step 1 — React Query removes ~60% of the file's responsibility, Zustand can absorb the UI state slice.
3. Hoist WiredCreatorToolsView's shared state to a Zustand slice. The 4-tab split is done but the parent still passes ~25 props to each tab. A slice at src/components/wired-tools/wiredToolsStore.ts would make each tab subscribe to the keys it needs.
4. Widen the component/hook Vitest coverage. The renderer-SDK mock layer is in place (tests/mocks/renderer-mock.ts) and the first two pilots — WidgetErrorBoundary and useDoorbellState — pass. Good follow-up targets: other *State hooks built on event reducers (useFurniChooserState, useUserChooserState, useFriendRequestState, useChatInputState), the useNitroQuery adapter (timeout + cleanup + accept-filter behavior), and the LoginView Form Actions happy/error paths. Each new test will likely need to add 1-3 named exports to the renderer mock.

Skipped intentionally and documented in commit messages:

• usePetPackageWidget and useWordQuizWidget god-hook splits — their "actions" mutate internal state, so a clean data/actions split would need either action arguments or a shared store first.
• useChatInputWidget / useChatWidget / useAvatarInfoWidget — large state machines, need per-file design before a mechanical split.

Anything else (the LoginView dialog split, the react-compiler/react-compiler warnings on the remaining big files, the set-state-in-effect sweep) is a downstream consequence of the above — easier and safer once the foundations are in place.

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Known logic bugs (independent of structural refactor)

These are runtime bugs spotted while doing the structural work. They are not fixed by the patterns above — they need their own PRs with manual QA. Listing them here because there is currently no GitHub Issues board on this repo.

Open

(none — both previously-listed bugs have landed; see "Recently fixed" below.)

Recently fixed (in this branch)

• LayoutFurniImageView / LayoutAvatarImageView async fetch race fixed. Both effects kicked off async image work (TextureUtils.generateImage / SDK resetFigure callback) and wrote the result via setImageElement / setAvatarUrl guarded only by an isMounted / isDisposed ref. If props changed twice in quick succession the older fetch could resolve last and overwrite the newer image. Both now capture a requestIdRef bumped at the start of the effect; the async callback bails when its captured id no longer matches the latest one. (React Query keyed on the props tuple would also work, but neither call goes through a composer / parser pair so the request-id ref is the lighter fix.)
• MainView CREATED/ENDED race fixed. Two independent useNitroEvent listeners on RoomSessionEvent.CREATED / RoomSessionEvent.ENDED could land out of order under flaky reconnects, leaving landingViewVisible contradicting the actual session state. Replaced with a single useNitroEventReducer that carries the active session's roomId: a CREATED bumps the tracked id and closes the landing view; an ENDED is honored only if its event.session.roomId matches the tracked id (or no session is active), otherwise it's a stale ENDED for a previous session and gets ignored.
• Doorbell close button didn't close while users were pending (useEffect(() => setIsVisible(!!users.length)) overrode the close). Fixed by src/components/room/widgets/doorbell/DoorbellWidgetView.tsx (separate dismissed state, visibility computed in render).
• Doorbell optimistic remove without rollback — the original answer() removed the user from the local list before the server confirmed via RSDE_ACCEPTED/RSDE_REJECTED, leaving client and server desynced if the network dropped. Fixed by removing the local removeUser call: the server-driven events now own the list. Note: a "pending" indicator (so users see their answer is in flight) is desirable — separate small PR.
• localStorage room history wiped on every tab close (RoomToolsWidgetView.tsx, useEffect on beforeunload removing nitro.room.history). Fixed by removing the beforeunload handler; history now persists across sessions, which is the only sensible meaning of localStorage. If "session-only" was the intent, the right primitive is sessionStorage — file an issue if that's actually desired.
• AvatarInfoPetTrainingPanelView null-pointer — roomSession.userDataManager.getPetData(parser.petId) could throw if roomSession was null at the moment the event arrived (between rooms). Fixed with ?. chain.
• useAvatarEditor set.paletteID null-pointer — buildCategory read set.paletteID on the line above its if(!set || !palette) return null guard. For categories where getSetType() legitimately returns null (PETS / MISC without server-side figure data), this threw and the avatar editor crashed on open, escalating to WidgetErrorBoundary. Split the guard so set is checked before its property access.