test: keep Desktop pane-focus setup outside cold imports

apps/desktop/src/store/session-pane-focus.test.ts

@@ -1,21 +1,24 @@
-import { beforeEach, describe, expect, it, vi } from 'vitest'
+import { afterEach, beforeAll, beforeEach, describe, expect, it } from 'vitest'
 
-async function setup() {
-  const tree = await import('@/components/pane-shell/tree/store')
-  const model = await import('@/components/pane-shell/tree/model')
-  const { registry } = await import('@/contrib/registry')
-  const session = await import('@/store/session')
-  const states = await import('@/store/session-states')
-  const { paneMirror } = await import('@/app/chat/pane-mirror')
+import { paneMirror } from '@/app/chat/pane-mirror'
+import * as model from '@/components/pane-shell/tree/model'
+import * as tree from '@/components/pane-shell/tree/store'
+import { registry } from '@/contrib/registry'
+import { applyDesktopOverlay } from '@/store/profile-share'
+import * as session from '@/store/session'
+import * as states from '@/store/session-states'
 
-  registry.register({
+// These app-lifetime watchers have no unsubscribe API. Install them once in
+// Vitest's isolated file graph, not once per case (which accumulates listeners).
+beforeAll(() => {
+  const disposeWorkspace = registry.register({
     area: 'panes',
     data: { placement: 'main', uncloseable: true },
     id: 'workspace',
     render: () => null,
     title: 'Chat'
   })
-  tree.declareDefaultTree(model.group(['workspace'], { active: 'workspace', id: 'main' }))
+
   tree.watchContributedPanes()
   paneMirror({
     source: states.$sessionTiles,
@@ -27,6 +30,23 @@ async function setup() {
     render: () => null,
     close: states.closeSessionTile
   })()
+
+  return disposeWorkspace
+})
+
+function resetState() {
+  // Empty the source while the mirror is live so it also disposes its pane.
+  states.discardSessionTile('canonical-chat')
+  tree.$layoutTree.set(null)
+  tree.$activeTreeGroup.set(null)
+  tree.$activePresetId.set('default')
+  session.$selectedStoredSessionId.set(null)
+  session.$lastReadAtBySessionId.set({})
+  window.localStorage.clear()
+}
+
+function setup() {
+  tree.declareDefaultTree(model.group(['workspace'], { active: 'workspace', id: 'main' }))
   session.$selectedStoredSessionId.set('previous-chat')
 
   const scope = {
@@ -42,17 +62,19 @@ async function setup() {
 }
 
 describe('focusing a saved Bot Chat requires a visible pane', () => {
-  let ctx: Awaited<ReturnType<typeof setup>>
+  let ctx: ReturnType<typeof setup>
   const paneId = 'session-tile:canonical-chat'
 
-  beforeEach(async () => {
-    window.localStorage.clear()
-    vi.resetModules()
-    ctx = await setup()
+  beforeEach(() => {
+    resetState()
+    ctx = setup()
+    expect(model.findGroupOfPane(tree.$layoutTree.get()!, 'workspace')?.id).toBe('main')
+    expect(states.$sessionTiles.get().map(tile => tile.storedSessionId)).toEqual(['canonical-chat'])
   })
 
-  it('re-adopts a saved tab after a profile overlay replaces the layout', async () => {
-    const { applyDesktopOverlay } = await import('@/store/profile-share')
+  afterEach(resetState)
+
+  it('re-adopts a saved tab after a profile overlay replaces the layout', () => {
     const { model, scope, states, tree } = ctx
     const saved = states.$sessionTiles.get()
     applyDesktopOverlay('imported-profile', {

evals/desktop-pane-fixture/README.md

@@ -0,0 +1,52 @@
+# Saved-pane fixture import-delay control
+
+From a root `npm ci` installation, run in `apps/desktop`:
+
+```sh
+npx vitest run --config ../../evals/desktop-pane-fixture/vitest.config.mts --reporter verbose
+npx vitest run --project ui src/store/session-pane-focus.test.ts --sequence.shuffle.tests --sequence.seed=12345 --reporter verbose
+```
+
+The Vite plugin appends an 11-second asynchronous wait to the real pane-tree
+store's evaluation. It does not mock pane functions, inspect source text in an
+assertion, lower a deadline, or alter the two test bodies. The UI test deadline
+remains 15 seconds and the default hook deadline remains 10 seconds. This is a
+scheduling-controlled reproduction of import latency, not a claim that a local
+machine reproduced the original CI load unassisted. It is opt-in, not a slow CI
+test.
+
+For A/B, apply this eval directory to the parent revision and run the same
+command, then run on the fixture fix. Base evaluates the graph inside each
+`beforeEach`; fixed evaluates it once during test collection. The delay marker
+appears twice on base and once on fixed. Expected: base fails with `Hook timed
+out in 10000ms`; fixed runs both behavioral assertions successfully.
+
+Measured on the initial base `fb3446a281e`:
+
+| Control | Result |
+| --- | --- |
+| Base + evaluation delay | 2 hook timeouts, 20.04s test phase |
+| Fixed + identical delay | 2 passed, 5ms test phase; 11.84s import phase |
+| Fixed normal and reversed test order (seed 12345) | 2 passed in each order |
+| Store directory, 8 workers | 123 files / 1491 tests passed |
+| Complete UI project, 8 workers | 753 files / 7355 assertions passed, but exit 1 from an unrelated Radix focus-scope timer's wrong-realm Event in `statusbar-visibility.test.tsx` |
+
+Mutation controls, applied separately to `session-states.ts` and then restored:
+
+- Remove `revealTreePane(paneId)` in `focusOpenSession`: the overlay re-adoption
+  case fails (`null` instead of `canonical-chat`); the miss case passes.
+- Make `focusWorkspaceOwnerSessionTile` return the stored id regardless of
+  `focusOpenSession`'s result: the miss case fails (`canonical-chat` instead of
+  `null`); the overlay case passes.
+
+The fixture uses the real registry, tree watcher, pane mirror, overlay, tile
+store, and focus helpers. Install app-lifetime watchers once per isolated Vitest
+file graph. Discard the fixture tile through the real action to clear both the
+reactive source and its persisted in-memory bucket; reset layout, focus, preset,
+selection, read baseline, and localStorage between cases. The mirror observes the
+discard and unregisters its contribution. No production API needs a test-only
+reset or disposer.
+
+If the host has exhausted inotify watches, prefix commands with
+`CHOKIDAR_USEPOLLING=true`; this changes file watching, not test deadlines. The
+recorded store/full-suite and final focused controls used that workaround.

evals/desktop-pane-fixture/vitest.config.mts

@@ -0,0 +1,28 @@
+// From apps/desktop: npx vitest run --config ../../evals/desktop-pane-fixture/vitest.config.mts
+// Replay a slow module evaluation without changing any pane behavior or deadlines.
+import { defineConfig, mergeConfig } from 'vitest/config'
+
+import desktopConfig from '../../apps/desktop/vite.config.ts'
+
+export default defineConfig(env =>
+  mergeConfig(desktopConfig(env), {
+    plugins: [
+      {
+        name: 'slow-pane-store-evaluation',
+        enforce: 'post',
+        transform(code: string, id: string) {
+          if (id.endsWith('/components/pane-shell/tree/store.ts')) {
+            return `${code}\nconsole.info('[pane-fixture] delaying real tree store evaluation by 11000ms');\nawait new Promise(resolve => setTimeout(resolve, 11000));\n`
+          }
+        }
+      }
+    ],
+    test: {
+      environment: 'jsdom',
+      setupFiles: ['./vitest.setup.ts'],
+      include: ['src/store/session-pane-focus.test.ts'],
+      globals: true,
+      testTimeout: 15_000
+    }
+  })
+)