# Framework remediation plan

**Status: completed.** The
repository has 102 maintained UI components, zero
undeclared non-native output emitters, zero components matching the scaffold
definition, and local styles on every component. The core reactive runtime is
48,124 minified bytes; component controllers ship separately at 24,027 bytes.

The §4.1 ownership migration is complete: `ui.css` contains global and
cross-cutting primitives only. Shared component foundations are carried by
three internal style-only components and render on demand; the former global
component families and standalone `wrn-next` generation class are absent.

Final validation passed the production, package, example, service, editor,
showcase-generation, typecheck, lint, formatting, public-API, visual-contract,
security, and runtime-size gates. The only skipped test is the explicitly
environment-dependent live PostgreSQL/MySQL test.

Production CSS delivery now links the selected palette/accent sheet (6,632
decoded bytes for dark/violet) instead of the complete 74,764-byte theme
matrix. The compatibility `theme.css` endpoint remains available but is not
linked by generated pages. Generated application declarations are committed
and checked for drift by `check:production`.

Written 2026-08-09, after the 0.8.6 release. Every number here was measured
against the completed tree, not estimated. Where a cause is not yet
proven the item says so and makes proving it step one — nothing in this document
should be implemented on the strength of a guess.

Each work item has the same four fields:

- **Issue** — what is wrong, stated so it can be disagreed with.
- **Evidence** — how we know, with the file or the measurement.
- **Change** — what to do.
- **How to test** — the check that fails before and passes after. If an item's
  test cannot fail before the change, the test is wrong; see the note on
  vacuous gates in §0.2.

---

## 0. Standing conventions

These are not tasks. They are the rules the tasks below are written against, and
they apply to all new work from now on.

### 0.1 A component owns everything it needs

**Every `.wrn` component is self-contained.** Markup, behaviour and styles live
in that one file. A component that needs a rule writes it in its own `style {}`
block, scoped to its own classes.

`ui.css` holds **global styles only** — resets, tokens, base element styling and
genuinely cross-cutting primitives. It is not a place to put component rules,
and no new component rule may be added to it. The reason is delivery: a
component's own styles ship only when that component renders, while `ui.css` is
served whole to every page on the site. See §4.1 for the migration and the
numbers.

Practical rules:

- CSS comments in a `style {}` block are `/* */` only. `//` is not a CSS comment
  and silently swallows the rule that follows it.
- Style the component's own BEM classes (`wrn-thing`, `wrn-thing__part`).
  Variants are data attributes: `[data-variant="soft"]`, not a class explosion.
- No Tailwind utility classes in component markup. See §4.3.

### 0.2 A test that cannot fail is not a test

Two gates in this repo passed for months while testing nothing, because both
were written against `getBoundingClientRect()`, which returns zeros in
happy-dom. The 0.8.5 focus trap had no coverage at all as a result.

**Before committing any test in this plan, delete the fix, watch the test fail,
then restore the fix.** If it passes with the fix removed, it is measuring
nothing. Never gate testable behaviour on measured geometry.

---

## 1. Bugs from this session

All five are **fixed and shipped in 0.8.6**. They are recorded here because each
one has a permanent guard that must not be removed, and because the pattern they
share is the subject of §2.

### 1.1 camelCase outputs never reached a parent binding — FIXED

**Issue.** HTML lowercases attribute names, so a parent writing `@sizeChange`
registered a handler under `sizechange`, while the component emitted
`sizeChange`. The registry lookup missed, fell through to a DOM dispatch, and
the parent binding was never invoked. No error at either end.

**Evidence.** All 17 camelCase outputs in the library were undeliverable:
`DataTable.pageChange`, `DataTable.rowClick`, `Map.markerClick`,
`ChatBubble.messageClick`, `LayoutSplitter.sizeChange`, the four `carousel.*`
and four `DragAndDrop.*` names, and the rest. Confirmed in a browser by reading
`__wrnexusOutputHandlers` off the component root and seeing the key casing.

**Change.** Done — `invokeComponentOutput` in
`packages/csr/src/reactive-runtime.ts` now falls back to a case-insensitive
lookup.

**How to test.**

```bash
bun test packages/csr/test/reactive.test.ts -t "camelCase output"
```

Verified failing with the fallback removed. Keep it that way.

### 1.2 Eighteen components emitted into the void — FIXED

**Issue.** An output only reaches a parent `@binding` when the component calls
`output.<name>()`. The runtime resolves parent handlers from a registry that
only `invokeComponentOutput` reads, so a component dispatching its own
`CustomEvent` — even a bubbling one on its own root — emits to nobody.

**Evidence.** 18 components did this. Card, Footer, Breadcrumb, Accordion,
alert, Badge, AnnouncementBar, AvatarGroup, ToggleCount and InputNumber were
converted; Marquee, Map, Timeline, List and SearchBox additionally had to
_declare_ the outputs they were already firing.

**Change.** Done. Note the deliberate exception: dispatching on `window` is
still correct and is left alone — that is how Toaster, Modal and DataTable
signal across component boundaries, where there is no parent binding to reach.

**How to test.**

```bash
bun test packages/ui/test/ui.test.ts -t "hand-built CustomEvent"
```

### 1.3 Ten theme tokens were referenced and never defined — FIXED

**Issue.** An undefined custom property does not warn; it resolves to nothing.
Focus rings drew with no colour in 14 components, every soft surface rendered
transparent in 27.

**Change.** Done — derived in `packages/styles/src/theme.ts`. Two traps worth
remembering: a check that reads the theme _source_ produces about a dozen false
positives because most tokens are generated per palette, so any such check must
read the **rendered** CSS; and the semantic spread must sit _before_ the
primary/secondary palette entries or it overrides them.

**How to test.** Load a page, then in the console collect every `var(--wrn-*)`
referenced by stylesheet rules and check each against
`getComputedStyle(document.documentElement)`. Expect 38 referenced, 0 undefined.

### 1.4 The modal focus trap had no coverage — FIXED

**Issue.** `isDialogVisible` and `focusableWithin` both gated on
`getBoundingClientRect()`, which is all zeros in happy-dom. The trap never ran
under test.

**Change.** Done — both read markers instead. One regression to remember: the
first fix used `data-show`, which broke Drawer, because a Drawer _animates_ open
and so cannot use `data-show`; every closed Drawer then looked open and held
`body { overflow: hidden }` forever. It reads `data-open` now.

**How to test.** `bun test packages/csr` — the dialog tests must fail if the
marker checks are reverted to geometry.

### 1.5 Roving focus matched `="false"` — FIXED

**Issue.** Attribute-presence selectors match any value, including `"false"`, so
read-only Steppers captured arrow keys from the page.

**Change.** Done — `rovingItemOff` treats bare as on and `"false"` as off.

**How to test.** `bun test packages/csr` roving cases; a read-only Stepper must
not consume `ArrowRight`.

---

## 2. The model is incomplete

This section is the real work. These are capability gaps, not defects, and they
are what currently limits what anyone can build. **§2.1 is the highest-value
item in this entire document.**

### 2.1 Development diagnostics — FIXED

**Issue.** Nothing in §1 produced a single diagnostic at any layer. That is not
five unlucky bugs; it is a systemic property. The failure mode is always
"nothing happens", which is the most expensive kind to debug because a bug is
indistinguishable from something you configured wrong.

**Evidence.** `packages/csr/src/reactive-runtime.ts` has 55 `catch` blocks, 11
of which swallow entirely, and 18 `console.error`/`console.warn` calls across
~70 kB of runtime. Undefined theme token → renders nothing. Wrong output casing
→ delivers nothing. Deferred state write → dropped. Component in a slot →
dropped. Object prop written inline → parsed as interpolation. None warn.

**Change.** Add a **dev-mode diagnostic layer**, stripped from production
builds. It should warn on at least:

1. `output.<name>()` called with no handler registered **and** no listener for
   the event — include the registry keys actually present, which is exactly what
   would have made §1.1 a five-minute bug.
2. A `@binding` naming a function that does not exist in scope.
3. A `var(--wrn-*)` referenced by a component but absent from the rendered
   theme.
4. A state write discarded because it happened after the client function
   returned (see §2.2).
5. A component tag dropped during slot flattening (see §2.4).
6. A prop declared as an object or array that arrived as an unparsed string.

Gate it on `process.env.NODE_ENV !== "production"` so the production bundle is
byte-identical to today. Route everything through one `warnOnce(code, message)`
helper with stable `WRN-` codes, so warnings are greppable and documentable and
a loop cannot spam the console.

**How to test.** A test per diagnostic that asserts the warning fires, plus one
asserting the production build contains none of them:

```bash
bun test packages/csr/test/diagnostics.test.ts
bun run build && grep -c "WRN-DEV-" examples/basic-app/dist/reactive.js   # expect 0
```

The production size ratchet now caps the split core runtime at 49,000 bytes; it
currently measures 48,124 minified bytes.

### 2.2 Deferred state writes — FIXED

**Issue.** State written after a client function returns — in a `setTimeout`, a
promise callback, an observer, a `pointermove` — is discarded. The peer-function
wrapper flushes the entry-time snapshot, so the later write is simply lost.

**Evidence.** This is why the focus trap, scrollspy, roving focus and the
splitter all had to be written as bespoke controllers inside the runtime.
Component-specific controllers are roughly 18% of `reactive.js` — that is a
model limitation being paid for in bundle size.

**Change.** Two parts, in order.

1. **Diagnose it** (part of §2.1). A dropped write must warn with the state key
   and the function name. Cheap, and it stops the silent-loss class immediately.
2. **Support it.** Let a client function return a promise, or expose an explicit
   `commit()`, so async writes reach the scope. This is the design decision —
   it wants a short written proposal before implementation, because it
   interacts with re-render batching.

**How to test.** A test where a client function writes state inside a
`setTimeout` and the DOM reflects it after the timer. This failed before the fix.

### 2.3 Reactive props and slot content — FIXED

**Issue.** Component props and slot content do not track page state. The
controlled-component pattern does not work at all: passing `value={pageState}`
renders the initial value and never updates.

**Why it matters most.** This is the biggest ceiling in the framework. It means
composition breaks down exactly where a component library needs it — a parent
cannot drive a child. Every workaround today is "hoist into page state and
re-render", which does not compose.

**Change.** Make prop expressions reactive bindings rather than one-time
interpolations, the way attribute bindings already work (`data-wrn-bind-*`).
The mechanism exists for attributes; extend it to component props.

If there is a hard reason this cannot work, **document that reason in the
component authoring guide** and give people a supported pattern instead. What
is not acceptable is the current state, where it looks like it should work and
quietly doesn't.

**How to test.** A page with `state n`, a component bound to `value={n}`, and a
button incrementing `n`; the component's rendered output must follow. Must fail
before the fix.

### 2.4 Nested component slots — FIXED

**Issue.** Nesting a component tag in another component's slot drops the tag and
leaves its children orphaned.

**Change.** Fix slot flattening to preserve nested component boundaries. Until
it is fixed, emit the §2.1 diagnostic — a dropped component must never be
silent.

**How to test.** Render `<Card><Badge label="x" /></Card>` and assert the Badge
root element exists in the output. This failed before the fix.

### 2.5 Structured object props — FIXED

**Issue.** An object or array prop written inline in an attribute is read as
interpolation. Three encodings were tried this session and all failed: bare
`{}` produced a 500, `({})` made `JSON.parse` throw so demos rendered silently
empty, and entity-escaping failed because the compiler passes attributes
undecoded. The only thing that works is hoisting to page state with
`JSON.parse`.

**Change.** Either support inline object literals in prop position, or reject
them at **compile time** with a message naming the prop and showing the hoist
pattern. A 500 at runtime and a silently empty component are both unacceptable
outcomes for a plain authoring mistake.

**How to test.** A compiler test asserting the specific diagnostic for
`items={{ a: 1 }}`, and one asserting the hoisted form still compiles.

### 2.6 i18n text is server-rendered — FIXED

**Original issue.** Translated text shipped as empty spans and was filled after
hydration. Navigation was blank until the runtime loaded.

**Why it matters.** This is an SSR-first framework failing to server-render
text. It is an SEO problem, a layout-shift problem, and it undercuts the
framework's central claim.

**Change.** Done. The active locale is resolved during SSR and translated text
is emitted into the HTML, keeping the client path for locale switches. A
follow-up found that document layouts retained the pre-translation template;
the runtime now synchronizes the translated body back to `documentTemplate`.

**How to test.**

```bash
curl -s http://localhost:3520/ | grep -c "Navigation"   # expect > 0
```

Assert against the raw server response with JavaScript disabled — not the
hydrated DOM.

---

## 3. Smaller but real

### 3.1 Dead outputs — FIXED (22 → 0)

Everything needed to do this in one pass is in this section: what was already
done, what is left, and which disposition each remaining component takes.

#### 3.1.1 Already done in 0.8.6 — do not redo

Fifteen components were fixed. Ten had outputs that were **declared but
incorrectly connected** — they dispatched a hand-built `CustomEvent` instead of calling
`output.*`, so the declaration was right and only the emit was wrong. Nothing
was added to these; they were reconnected:

> Card, Footer, Breadcrumb, Accordion, alert, Badge, AnnouncementBar,
> AvatarGroup, ToggleCount, InputNumber

Five more were **firing events they had never declared**, so no caller could
bind to them at all. These gained an `outputs {}` block _and_ were routed
through `output.*`:

| Component   | Outputs added                   | Fires when                                             |
| ----------- | ------------------------------- | ------------------------------------------------------ |
| `Map`       | `markerClick`, `select`, `zoom` | marker pressed (both names fire); zoom in/out pressed  |
| `SearchBox` | `search`, `clear`               | form submitted; clear button pressed                   |
| `Marquee`   | `pause`, `resume`               | hover, focus, or the pause/play button                 |
| `List`      | `select`                        | item pressed — **only items with an `href`**, see §3.4 |
| `Timeline`  | `select`                        | item pressed                                           |

Verified firing in a browser: `SearchBox`, `Marquee`, `List`, `Timeline`, plus
all ten reconnected components. **`Map` was not verified** — its three outputs were
converted by the same mechanical change and the build passes, but no Map was on
the probe page. Put one on a page and confirm before treating it as done.

#### 3.1.2 Original remaining work — resolved

**Original issue.** These were not incorrectly connected. All nine were **pure scaffolds**: roughly 25
lines each, zero state, zero functions, no style block, no event handlers. They
are markup shells that declare outputs. "Add an emitter" is not the work — there
is nothing to emit from.

**The finding that should drive the decision: most of them duplicate a component
that already works.** This is the Table situation again, where Table was removed
because DataTable superseded it.

| Scaffold              | Dead outputs                              | Already works elsewhere                                                                                        |
| --------------------- | ----------------------------------------- | -------------------------------------------------------------------------------------------------------------- |
| `FileUpload`          | upload, progress, success, cancel, remove | `FileInput` (3 fns, 4 outputs) + `FileUploadProgress` (5 fns, 3 outputs), plus the `@wrnexus/uploader` package |
| `ToastNotifications`  | add, dismiss, clear, action               | `Toaster` (961 lines, 40 fns, fully built)                                                                     |
| `Toast`               | dismiss                                   | `Toaster`, same                                                                                                |
| `AdvancedDatePicker`  | open, close, clear                        | `DatePicker` (8 fns, 8 outputs)                                                                                |
| `AdvancedRangeSlider` | start, end                                | `RangeSlider` (11 fns, 8 outputs)                                                                              |
| `Chart`               | dataPointClick, legendToggle              | nothing — needs building                                                                                       |
| `TreeView`            | expand, collapse                          | nothing — needs building                                                                                       |
| `Confetti`            | start, complete                           | nothing — needs building                                                                                       |
| `CopyMarkup`          | success                                   | nothing — and `Clipboard` is a scaffold too (0 fns)                                                            |

**Change, in two groups.**

_Group A — supersede and remove: 5 components, 15 of the 22 outputs._
`FileUpload`, `ToastNotifications`, `Toast`, `AdvancedDatePicker`,
`AdvancedRangeSlider`. Each has a working counterpart, so building them a second
time adds duplicated surface area to maintain for no new capability. Removing
them is a **breaking change** and needs a migration entry naming the replacement
per component, in the same shape as the Table removal.

This is a judgement call and it is yours: superseding is cheap and honest,
keeping them means committing to build five more components properly.

_Group B — build for real: 4 components, 7 outputs._ `Chart`, `TreeView`,
`Confetti`, `CopyMarkup` (and `Clipboard` alongside it, since it is in the same
state). These have no counterpart, so their outputs only become meaningful once
the component exists. Build each under §0.1 — markup, behaviour and styles in
its own `.wrn`.

Notes that will save time:

- **`Chart` needs a rendering decision before any output can mean anything.** An
  inline SVG renderer keeps the CSP story intact and adds no dependency; a
  charting library ships faster but introduces a third-party runtime dependency
  the framework does not currently carry. Decide that first — `dataPointClick`
  and `legendToggle` are trivial once something is actually drawn.
- **`TreeView` should reuse the existing roving-focus controller** rather than
  growing a new one. Expand/collapse state must live in the component, not in a
  deferred callback — see §2.2.
- **`CopyMarkup`'s props are generic input boilerplate** (`name`, `value`,
  `placeholder`, `type`, `min`) rather than anything copy-related, which
  suggests it was generated rather than designed. Worth deciding what it is
  meant to be before building it, or folding it into `Clipboard`.

Rough effort: `CopyMarkup`/`Clipboard` and `Confetti` are small and
self-contained. `TreeView` is medium — recursive rendering plus expand state.
`Chart` is the large one.

**How to test.**

- The ratchet in `packages/ui/test/ui.test.ts` is now pinned at **0**.
- For a removal: `bun run check:public-api` flags the dropped export, and the
  migration entry is required before `release:prepare` will pass.
- For a build: the component renders, its behaviour works in a browser, its
  outputs reach a page-level `@binding`, and it carries its own styles. Bind the
  output from a page and confirm it arrives — §1.1 and §1.2 are both cases where
  reading the source said it worked and the browser said otherwise.

### 3.2 Component scaffolds — FIXED (28 → 0)

**Original issue.** No style block, no functions and no event handlers — markup shells,
the same shape as the Table scaffold that was removed and the LayoutSplitter
scaffold that was rebuilt. A scaffold in a published library is a promise the
library does not keep.

**Evidence.** Counted as components with no `style {}`, no `function` and no
`@handler`. An earlier figure of 23 in the audit was measured with a looser rule;
28 was the number:

> AdvancedDatePicker, AdvancedRangeSlider, AuthSplitLayout, avatar, Blockquote,
> button, Chart, Clipboard, Confetti, CopyMarkup, DataMap, DragAndDrop,
> FeatureIconCard, FileUpload, HeroActions, LegendIndicator, ListGroup,
> MarketingSectionHeader, progress, Rating, skeleton, spinner, StyledIcon,
> TextLink, Toast, ToastNotifications, TreeView, WysiwygEditor

**Nine of these are the §3.1 dead-output components** — AdvancedDatePicker,
AdvancedRangeSlider, Chart, Confetti, CopyMarkup, FileUpload, Toast,
ToastNotifications, TreeView. Do §3.1 first and this list drops to 19 without
any extra work. Do not plan the two items separately.

Separately, 58 components carried the standalone `wrn-next` scaffold class in
the original audit; **zero retain it now**. Component-specific BEM identifiers
such as `wrn-next--alert` remain locally owned implementation details, but no
component is bound to a global stylesheet through the generation artefact.

**Change.** Rebuild them under §0.1, or remove them. Note that several are
primitives where a scaffold is nearly the right answer — `skeleton`, `spinner`,
`avatar`, `Blockquote` and `StyledIcon` need styles but genuinely need no
behaviour, so for those "rebuild" means moving their CSS out of `ui.css` into
the component and nothing more. Sort the list into "needs behaviour" and "needs
only its styles" before starting; the second group is much larger and much
cheaper than it looks.

**How to test.** Per component: it renders, any interactive behaviour works in a
browser, its outputs reach a page-level binding, and it carries its own styles.
Track the count down the same way as §4.1:

```bash
bun run build && gzip -c examples/basic-app/dist/ui.css | wc -c
```

### 3.3 Tailwind component migrations — FIXED (7 → 0)

**Original issue.** `List` (23 utility classes), `InputNumber` (22), `Marquee` (15),
`TextLink` (14), `Map` (12), `SearchBox` (8), `Timeline` (8) still style
themselves with utility classes in markup.

All seven now use local `wrn-*` BEM styles. `InputNumber` styles are emitted as
component-scoped CSS and therefore do not appear in the global `ui.css` file.

**Change.** Migrate to `wrn-*` BEM classes in the component's own `style {}`
block, per §0.1. Note this changes the rendered class list, so application CSS
selecting on those utilities stops matching — it needs a migration note, exactly
as the layout group did in 0.8.6.

**How to test.**

```bash
bun run check:ui-visual        # review the rendered diff deliberately
bun run generate:ui-visual     # only after reviewing
```

Compare screenshots before and after; the visual result should be unchanged.

### 3.4 `List` selection without an href — FIXED

**Issue.** The `@click` handler sits on the `item.href` branch only, so an item
without a link is not selectable. Pre-existing, and surprising.

**Change.** Decide deliberately: either fire `select` for all items, or document
that `List` is a navigation component and non-link items are inert.

**How to test.** Render a `List` with items lacking `href`, click one, assert
whichever behaviour was chosen.

---

## 4. Delivery and the dev loop

### 4.1 Global `ui.css` migration — FIXED

**Original issue.** `ui.css` was **175,848 bytes, 26,350 gzipped**, served on
every page. Only **42 of 108** components had a local `style {}` block.

**Result.** The maintained library now has **102 of 102** components with local
styles. Built `ui.css` is **15,927 bytes / 3,762 gzipped**. The `.wrn-next`,
`.wrn-btn`, `.wrn-dropdown`, `.wrn-alert`, `.wrn-card`, `.wrn-footer`,
`.wrn-metric-card`, and `.wrn-segmented-group` global families are gone.
Reusable field, select, color, and size foundations live in three internal
style-only components; the renderer emits and deduplicates them only when a
component that needs them renders. An example-app SSR guard verifies that
on-demand path, while the UI suite prevents the global families or standalone
`wrn-next` class from returning.

**Change.** Done in groups with the visual contract regenerated after each
migration.

**How to test.** Track the number down, every time:

```bash
ls packages/ui/components/*.wrn | wc -l                          # 102
grep -lE '^\s*style\s*\{' packages/ui/components/*.wrn | wc -l   # 102
bun run build
bun -e "const b=await Bun.file('examples/basic-app/dist/ui.css').arrayBuffer(); console.log(Bun.gzipSync(new Uint8Array(b)).length)" # 3762
```

Add a ratchet test asserting the gzipped size only ever decreases, so this
cannot silently regress.

### 4.2 Dev-server package UI hot reload — FIXED

**Issue.** Editing a component under `packages/ui` does not hot-reload. Every UI
change this session needed a full server restart, which is the single biggest
drag on the edit loop.

**Evidence, and what is _not_ yet proven.** The watcher is connected correctly:
`componentDirs` includes `uiComponentsDir()` and is passed as `extraDirs`
(`packages/dev-server/src/index.ts:706-723`), external paths arrive absolute
(`packages/dev-server/src/watch.ts:104`), and `hotUpdate` calls
`invalidateModule` and rebuilds the router with `componentDirs`
(`index.ts:600-616`). So the change _is_ observed. **Why it does not take effect
is not yet diagnosed.**

One concrete lead, not a conclusion: `index.ts:619` filters to
`files.filter((file) => !isAbsolute(file))`, which excludes every
`packages/ui` path from the app-file branch below it.

**Change.** Step one is to confirm the cause — add a log at the top of
`hotUpdate` printing the received paths, edit a `.wrn` under `packages/ui`, and
follow it. Only then fix. Do not implement against the lead above without
confirming it.

**How to test.** Start the dev server, edit visible text in a
`packages/ui/components/*.wrn`, reload the page **without restarting**, and see
the change. That is the whole acceptance criterion.

### 4.3 Per-process development caches — FIXED

**Original issue.** Running `bun test` or `check:production` while a dev server was up
empties `.wrnexus`, and every client module then 404s until a restart. This
produced several confusing "the Sidebar is broken" symptoms this session that
were not component bugs at all.

**Evidence.** `resetDevCache` in `packages/dev-server/src/cache.ts:24-30`
`rmSync`s the whole cache directory on startup, unless
`WRNEXUS_PRESERVE_CACHE=1`. Any dev server a test spawns against the repo root
therefore deletes the running server's cache.

**Change.** The first option was implemented: each process uses
`.wrnexus-<pid>`, normal server shutdown removes its directory, and
`.wrnexus-*/` is excluded by Git, ESLint, TypeScript, and Prettier so an
interrupted process cannot pollute a commit or a repository-wide tool run.

The considered options were:

- Give each dev-server instance its own cache directory (keyed by port or pid),
  so instances cannot collide; or
- Have the test harness set `WRNEXUS_PRESERVE_CACHE=1` and use a temp cache dir
  for every spawned server.

Prefer the first — it fixes the class rather than one caller. Either way,
`resetDevCache` should refuse to delete a cache directory another live server
owns.

**How to test.** Start the dev server, load a page, run `bun test packages` to
completion, reload the page without restarting. It must still work.

### 4.4 Generated artefact ordering — FIXED

**Original issue.** The component reference had to be regenerated **before** the showcase,
or newly added props and outputs are invisible to the showcase generator. This
is undocumented and cost real time.

**Change.** Done. `generate:pages` regenerates the reference first, and both
generators emit idempotent Prettier-compatible artifacts.

**How to test.** Add a prop to a component, run the showcase generator without
regenerating the reference, and assert it errors rather than silently emitting a
stale page.

### 4.5 Compiler diagnostics for authoring traps — FIXED

**Issue.** Block comments are not allowed inside `props {}` — line comments
only — and `state page` collides with the `page` keyword. Both currently fail in
confusing ways.

**Change.** Detect both at compile time with a message that names the problem.

**How to test.** Compiler tests asserting the specific diagnostics.

---

### 4.6 Runtime and client-module size — measured

A per-subsystem measurement of `reactive.js` and of the generated client
modules, made by minifying the runtime repeatedly with one subsystem removed
each time. Source-byte share was not used: it overstates code that minifies
well and understates code that does not, and the split/keep decision turns on
the real number.

**This corrects the earlier audit**, which claimed component controllers were
"about 18%" of the runtime and concluded that splitting saves "3-4 kB gzipped".
Both figures were wrong, and the conclusion that followed from them was wrong.

#### Runtime before remediation

`reactive.js` was **70,101 bytes minified, 21,736 gzipped**. Removing each
subsystem and re-minifying gives its true cost:

| Subsystem         | Minified | Share |
| ----------------- | -------- | ----- |
| Select/combobox   | 7,852    | 11.2% |
| PinInput          | 3,734    | 5.3%  |
| async boundaries  | 3,151    | 4.5%  |
| Navbar            | 2,419    | 3.5%  |
| splitters         | 2,083    | 3.0%  |
| roving focus      | 1,646    | 2.3%  |
| modal dialogs     | 1,611    | 2.3%  |
| csr fetch         | 1,547    | 2.2%  |
| anchored overlays | 1,419    | 2.0%  |
| scrollspy         | 1,373    | 2.0%  |
| preferences       | 1,045    | 1.5%  |
| toast             | 534      | 0.8%  |

Component-specific controllers (everything except async boundaries and csr
fetch, which are framework features) total **23,722 minified / 6,660 gzipped —
30.6% of what a visitor downloads.** The irreducible core is 46,379 minified /
15,076 gzipped: the expression engine, the scope and reactivity core, and loop
diffing.

After the split, the core runtime is **48,124 minified bytes** and the
on-demand controller asset is **24,027 minified bytes**. `/` requests no
controller asset.

#### How much of it a page actually used before the split

Measured against the example app by checking which controller markers appear in
the served HTML:

| Page          | Controllers used   |
| ------------- | ------------------ |
| `/`           | **0 of 10**        |
| `/login`      | **0 of 10**        |
| `/layout`     | 1 of 10 (splitter) |
| `/navigation` | 5 of 10            |

A typical page downloads and parses 6.6 kB gzipped of controller code it never
executes. The Select controller — the single largest item at 7,852 bytes — is
used by none of the pages above.

**Change.** Split the component controllers out of the core runtime and load
them on demand, keyed on the marker attribute that already gates each one
(`data-wrn-select`, `data-wrn-splitter`, `data-wrn-scrollspy` and so on). The
gating logic exists; only the loading boundary is missing. Keep the core
runtime as one immutable-cached file.

**How to test.** Assert the core bundle size, and per page assert that a
controller chunk is requested only when its marker is present:

```bash
bun run scripts/lib/measure-runtime-size.ts   # core must stay under budget
```

Plus a browser check on `/`: zero controller chunks requested.

#### Generated client modules — FIXED

Before remediation, `/navigation` measured:

- **490,212 bytes decoded** across 11 client modules, **21,026 transferred** —
  a 23:1 compression ratio.
- The largest single module is **269,117 bytes** decoded, of which **89.8% is
  duplicated lines**.
- One line appears **162 times**: `brand = context.state.brand; topLinks =
context.state.topLinks; ...` — the full state-restore prologue.

After hoisting and closure deduplication, the page is **101,253 decoded bytes**;
the largest module is **51,946 bytes** with **2.4% duplicated lines**.

Gzip hides this on the wrn, but **parse and compile cost scales with decoded
bytes, not transferred bytes**. Half a megabyte of JavaScript is parsed to run
one page.

**Cause.** `packages/compiler/src/client-codegen.ts:228-264` inlines the state
sync into _every peer-function alias, in every client function_. Each alias
emits `syncStateToContext` once and `syncStateFromContext` three times — the
catch path, the promise `finally`, and the synchronous path. The output is
O(functions x peers x state variables). With ~19 state variables and 81 peer
aliases in that module, that is several thousand generated assignments.

**Change.** Hoist the sync out of the per-alias wrapper. The cheapest version
with no change to how bodies are written: emit **one** pair of closures per
client function and have every peer alias call them, instead of inlining the
sync per alias:

```js
const __flush = () => {
  context.state.brand = brand; /* ... */
};
const __restore = () => {
  brand = context.state.brand; /* ... */
};
const __peer =
  (name) =>
  (...args) => {
    __flush();
    let r;
    try {
      r = context.functions[name](...args);
    } catch (e) {
      __restore();
      throw e;
    }
    if (r && typeof r.then === "function") return Promise.resolve(r).finally(__restore);
    __restore();
    return r;
  };
const doThing = __peer("doThing");
```

That removes the peer multiplier — the dominant factor — and takes the 81
copies down to roughly one per function. It is a codegen change only, with no
change to semantics or to how anyone writes a component.

A larger follow-up, if the first is not enough: keep state in a single object
and rewrite state identifiers in the body to reference it, which removes the
per-variable multiplier as well. That one needs the body transform and should
be measured before it is attempted.

**How to test.** Pin decoded size, because gzip hides regressions here:

```bash
bun run build
# assert the largest generated client module is under budget, DECODED not gzipped
```

Add the ratio itself as a signal: any module compressing better than about 10:1
is duplicating itself and should fail the check. Existing behaviour is covered
by the original 1,427-test suite; this is purely a size
assertion on top.

### 4.7 Destructive generator — REMOVED

**Original issue.** The script failed partway through with
`TypeError: factories[entry.category] is not a function`
(`scripts/generate-ui-complete-catalog.mjs:156`) — but not before it has already
started writing. It **overwrote real components with bare scaffolds and deleted
others**, then crashed, leaving the library in a wrecked state. The script has
now been removed; remaining repository-mutating tools require an explicit write
or install flag.

**Evidence.** Running it on 2026-08-09 rewrote Accordion, alert, Badge,
AvatarGroup, ToggleCount and LayoutSplitter down to ~15-line stubs, deleted 24
component files, and renamed `Card`, `Container`, `Divider` and `Grid` to
lowercase — 113 files changed in total. Nothing in `package.json` references it,
so no gate runs it and no gate would have caught the damage.

**Why it is worse than it looks.** The rename is the dangerous part. Windows is
case-insensitive, so after `git checkout -- .` the tree reported **clean** while
four components were still misnamed on disk. Only a test failure exposed it. On
a case-sensitive filesystem the same script produces duplicate files instead.

**Change.** Pick one:

- **Delete it.** `generate-ui-component-reference.mjs` is the maintained
  generator, it is connected into `release:prepare`, and it works. If this script is
  redundant, it is a loaded gun in the repo for no benefit.
- **Or fix and gate it**: make it write to a temp directory and swap atomically
  only on success, so a mid-run crash cannot leave a partial library. Then add
  it to a check so it cannot rot again.

Whichever is chosen, **no script that rewrites `packages/ui/components/` should
write in place.** Generate to a staging directory, validate, then move.

**Original related finding:** several other ungated scripts mutated
the repository or start servers when run — `install-captcha.mjs`, the
`validate-*.mjs` and `verify-*.mjs` families, and `benchmark-framework.mjs`.
Obsolete validators were removed, current validators were repaired, and useful
mutating scripts now require explicit flags. A
`scripts/` directory where running a file at random can scaffold apps, start
dev servers on ports 3000-3002 and rewrite the component library is a hazard to
anyone exploring the repo, human or otherwise.

**How to test.** After fixing or deleting:

```bash
git status --porcelain   # must be empty after running any generator twice
```

Add a check that runs each generator in `--check` mode and fails if it would
modify tracked files, the way `check:workspace` and `check:public-api` already
do.

### 4.8 Filename casing — FIXED

**Issue.** Four components were tracked in git under lowercase names
(`card.wrn`, `container.wrn`, `divider.wrn`, `grid.wrn`) while existing on disk
under capitalised ones. Windows hid the discrepancy; `git status` reported clean.

**Why it matters.** `ui-redesign-contract.test.ts` reads the real directory and
expects `Card.wrn`. **On a fresh clone on Linux or in CI the files arrive
lowercase and that test fails** — a latent break that could not reproduce on a
Windows workstation.

**Change.** Done — the index now tracks the capitalised names, matching the
component each file declares (`component Card`, `component Container`, and so
on) and matching every other component in the library.

**How to test.**

```bash
git ls-files packages/ui/components/ | grep -iE '/(card|container|divider|grid)\.wrn'
```

must return the capitalised names. Better, set `git config core.ignorecase
false` locally so a future rename cannot hide again, and consider a check that
compares `git ls-files` against the on-disk listing byte for byte.

## 5. Historical order of work

This is the execution order used during remediation, retained as implementation
history. Every row is complete.

| #   | Item                                                      | Why now                                                                                                                                         |
| --- | --------------------------------------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------- |
| 0   | §4.7 neutralise the destructive generator                 | Safety, not improvement. Running one file in `scripts/` at random can shred the component library. Do this before anyone else touches the repo. |
| 1   | §2.1 dev-mode diagnostics                                 | Changes the debugging economics of everything else. Every §1 bug would have been minutes instead of hours.                                      |
| 2   | §2.3 reactive props                                       | The biggest capability ceiling. Composition does not work without it.                                                                           |
| 3   | §2.6 server-rendered i18n                                 | Contained work; the core SSR claim currently fails on text.                                                                                     |
| 4   | §4.2 + §4.3 dev loop                                      | Cheap, and it compounds across every task below.                                                                                                |
| 5   | §4.6 de-duplicate generated client modules                | 490 kB decoded parsed per page, 90% of it duplicated. Codegen-only, no API impact.                                                              |
| 6   | §4.1 finish the CSS migration                             | Localized component ownership and reduced the always-served sheet by ~160 kB.                                                                   |
| 7   | §4.6 split controllers out of the core runtime            | 6.6 kB gzipped a typical page never executes.                                                                                                   |
| 8   | §3.1 Group A: supersede the 5 duplicate scaffolds         | 15 of the 22 dead outputs, and 5 fewer components to maintain. Needs a migration entry, not new code.                                           |
| 9   | §3.2 scaffolds that need only their styles                | Larger and cheaper than it looks; folds into item 6.                                                                                            |
| 10  | §3.1 Group B: build Chart, TreeView, Confetti, CopyMarkup | Real component work. Chart needs a rendering decision first.                                                                                    |

§2.2, §2.4 and §2.5 fold into item 1 as diagnostics first, then into item 2 as
model work.

**What I would resist: adding more components.** The library is 108 wide and
roughly 60% deep. Everything above is depth.

## 6. A note on strategy

47 packages before 1.0 is a large surface area. Each is a public API you have
committed to, a version to align and a migration note to write — the 0.8.6
release touched 117 files to change one behaviour. The gate makes that
tractable, but tractable is not free. Some packages (`native`, `mobile`,
`playground`, `mcp`, `graphql`) look like option value rather than load-bearing.
Consolidating them would buy speed on exactly the model gaps in §2 that
currently limit users.

This is a judgement call, not a defect, and it is yours to make.
