Merge PR #500 into CI optimization

packages/client/ui-layout/tests/app-frame.spec.tsx

@@ -0,0 +1,208 @@
+// @vitest-environment jsdom
+/**
+ * AppFrame interaction spec: drag sequences (pointer capture + rAF flush),
+ * concession response to viewport change, details stays mounted at zero
+ * width. jsdom has no layout engine, so the frame width comes from a mocked
+ * getBoundingClientRect and resizes are driven through the ResizeObserver
+ * stub; assertions read the inline grid template.
+ */
+import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest'
+import { act, cleanup, render } from '@testing-library/react'
+import { createSnapshotStore } from '@deepseek-ai/dsh-client-web-react'
+import { AppFrame, CenterColumn, DetailsColumn, type PanelState } from '@deepseek-ai/dsh-client-ui-layout/client'
+import { clampWidth } from '@deepseek-ai/dsh-client-ui-layout/client'
+
+/** Observer stub: captures the callback so tests can fire resizes manually. */
+let fireResize: (() => void) | null = null
+class ResizeObserverStub {
+  #cb: ResizeObserverCallback
+  constructor(cb: ResizeObserverCallback) { this.#cb = cb }
+  observe(): void { fireResize = () => { this.#cb([], this as unknown as ResizeObserver) } }
+  unobserve(): void {}
+  disconnect(): void { fireResize = null }
+}
+
+let frameWidth = 1920
+
+function mountFrame() {
+  window.innerWidth = frameWidth // first-render viewport source before the observer fires
+  const sidebar = createSnapshotStore<PanelState>({ open: true, width: 300 })
+  const details = createSnapshotStore<PanelState>({ open: true, width: 360 })
+  const utils = render(
+    <AppFrame
+      useSidebar={sidebar.useSelector}
+      useDetails={details.useSelector}
+      setSidebarWidth={(px) => { sidebar.update((d) => { d.width = clampWidth(px, 240, 420) }) }}
+      setDetailsWidth={(px) => { details.update((d) => { d.width = clampWidth(px, 300, 520) }) }}
+      sidebar={<div data-testid="sidebar-content" />}
+    >
+      <CenterColumn><div data-testid="center-content" /></CenterColumn>
+      <DetailsColumn><div data-testid="details-content" /></DetailsColumn>
+    </AppFrame>,
+  )
+  const frame = utils.container.firstElementChild as HTMLElement
+  return { sidebar, details, frame, ...utils }
+}
+
+function tracks(frame: HTMLElement): number[] {
+  const m = /^(\d+)px minmax\(0, 1fr\) (\d+)px$/.exec(frame.style.gridTemplateColumns)
+  if (m === null) throw new Error(`unexpected template: ${frame.style.gridTemplateColumns}`)
+  return [Number(m[1]), Number(m[2])]
+}
+
+function drag(handle: Element, fromX: number, toX: number): void {
+  const down = new PointerEvent('pointerdown', { pointerId: 1, clientX: fromX, bubbles: true })
+  const move = new PointerEvent('pointermove', { pointerId: 1, clientX: toX, bubbles: true })
+  const up = new PointerEvent('pointerup', { pointerId: 1, clientX: toX, bubbles: true })
+  act(() => { handle.dispatchEvent(down) })
+  act(() => { handle.dispatchEvent(move); vi.advanceTimersByTime(20) })
+  act(() => { handle.dispatchEvent(up) })
+}
+
+beforeEach(() => {
+  frameWidth = 1920
+  vi.useFakeTimers()
+  vi.stubGlobal('ResizeObserver', ResizeObserverStub)
+  vi.stubGlobal('requestAnimationFrame', (cb: FrameRequestCallback) => setTimeout(() => { cb(0) }, 16) as unknown as number)
+  vi.stubGlobal('cancelAnimationFrame', (h: number) => { clearTimeout(h) })
+  window.innerWidth = frameWidth
+  Element.prototype.getBoundingClientRect = function () {
+    return { width: frameWidth, height: 1080, top: 0, left: 0, right: frameWidth, bottom: 1080, x: 0, y: 0, toJSON: () => ({}) } as DOMRect
+  }
+  // jsdom lacks pointer capture: emulate per-element so hasPointerCapture gates pass.
+  const captured = new WeakSet<Element>()
+  Element.prototype.setPointerCapture = function () { captured.add(this) }
+  Element.prototype.releasePointerCapture = function () { captured.delete(this) }
+  Element.prototype.hasPointerCapture = function () { return captured.has(this) }
+})
+
+afterEach(() => {
+  cleanup()
+  vi.useRealTimers()
+  vi.unstubAllGlobals()
+})
+
+describe('AppFrame', () => {
+  it('renders three tracks from panel state', () => {
+    const { frame } = mountFrame()
+    expect(tracks(frame)).toEqual([300, 360])
+  })
+
+  it('sidebar drag widens through rAF-batched pointer moves', () => {
+    const { frame } = mountFrame()
+    const handles = frame.querySelectorAll('[class*="handle"]')
+    drag(handles[0]!, 300, 350)
+    expect(tracks(frame)[0]).toBe(350)
+  })
+
+  it('details drag widens leftward (negative dx grows the panel)', () => {
+    const { frame } = mountFrame()
+    const handles = frame.querySelectorAll('[class*="handle"]')
+    drag(handles[1]!, 1560, 1500)
+    expect(tracks(frame)[1]).toBe(420)
+  })
+
+  it('drag base is the rendered (concession-clamped) width, not the preference', () => {
+    frameWidth = 1250 // step-2 squeeze: details renders 310 while preference is 360
+    const { frame, details } = mountFrame()
+    expect(tracks(frame)).toEqual([300, 310])
+    const handles = frame.querySelectorAll('[class*="handle"]')
+    drag(handles[1]!, 940, 950) // shrink by 10 from the rendered width
+    expect(details.getSnapshot().width).toBe(300)
+  })
+
+  it('details column stays mounted at zero width', () => {
+    const { frame, details, getByTestId } = mountFrame()
+    act(() => { details.update((d) => { d.open = false }) })
+    expect(tracks(frame)).toEqual([300, 0])
+    expect(getByTestId('details-content')).toBeTruthy()
+    expect(frame.hasAttribute('data-details-collapsed')).toBe(true)
+  })
+
+  it('viewport shrink triggers the concession chain via ResizeObserver', () => {
+    const { frame } = mountFrame()
+    frameWidth = 1250
+    act(() => { fireResize?.(); vi.advanceTimersByTime(20) })
+    expect(tracks(frame)).toEqual([300, 310])
+    frameWidth = 1920
+    act(() => { fireResize?.(); vi.advanceTimersByTime(20) })
+    expect(tracks(frame)).toEqual([300, 360])
+  })
+
+  it('drag handles disappear for collapsed columns', () => {
+    const { frame, details, sidebar } = mountFrame()
+    expect(frame.querySelectorAll('[class*="handle"]')).toHaveLength(2)
+    act(() => { details.update((d) => { d.open = false }) })
+    expect(frame.querySelectorAll('[class*="handle"]')).toHaveLength(1)
+    act(() => { sidebar.update((d) => { d.open = false }) })
+    expect(frame.querySelectorAll('[class*="handle"]')).toHaveLength(0)
+  })
+})
+
+describe('AppFrame — guard branches', () => {
+  it('pointer moves without capture are ignored (no width write)', () => {
+    const { frame, sidebar } = mountFrame()
+    const handle = frame.querySelectorAll('[class*="handle"]')[0]!
+    const before = sidebar.getSnapshot().width
+    // Move + up without a preceding pointerdown: hasPointerCapture is false.
+    act(() => {
+      handle.dispatchEvent(new PointerEvent('pointermove', { pointerId: 9, clientX: 500, bubbles: true }))
+      vi.advanceTimersByTime(20)
+      handle.dispatchEvent(new PointerEvent('pointerup', { pointerId: 9, clientX: 500, bubbles: true }))
+    })
+    expect(sidebar.getSnapshot().width).toBe(before)
+  })
+
+  it('two moves inside one frame coalesce through the pending rAF', () => {
+    const { frame, sidebar } = mountFrame()
+    const handle = frame.querySelectorAll('[class*="handle"]')[0]!
+    act(() => { handle.dispatchEvent(new PointerEvent('pointerdown', { pointerId: 1, clientX: 300, bubbles: true })) })
+    act(() => {
+      // Two moves before the frame flushes: the second must ride the pending
+      // rAF (frame.current ??= guard), and the flush sees the latest x.
+      handle.dispatchEvent(new PointerEvent('pointermove', { pointerId: 1, clientX: 320, bubbles: true }))
+      handle.dispatchEvent(new PointerEvent('pointermove', { pointerId: 1, clientX: 340, bubbles: true }))
+      vi.advanceTimersByTime(20)
+    })
+    act(() => { handle.dispatchEvent(new PointerEvent('pointerup', { pointerId: 1, clientX: 340, bubbles: true })) })
+    expect(sidebar.getSnapshot().width).toBe(340)
+  })
+
+  it('pointerup with a pending rAF cancels it and commits the final position', () => {
+    const { frame, sidebar } = mountFrame()
+    const handle = frame.querySelectorAll('[class*="handle"]')[0]!
+    act(() => { handle.dispatchEvent(new PointerEvent('pointerdown', { pointerId: 1, clientX: 300, bubbles: true })) })
+    act(() => {
+      handle.dispatchEvent(new PointerEvent('pointermove', { pointerId: 1, clientX: 360, bubbles: true }))
+      // No timer advance: the rAF is still pending when pointerup arrives.
+      handle.dispatchEvent(new PointerEvent('pointerup', { pointerId: 1, clientX: 360, bubbles: true }))
+    })
+    expect(sidebar.getSnapshot().width).toBe(360)
+  })
+
+  it('zero-width resize reports are ignored (display:none window)', () => {
+    const { frame } = mountFrame()
+    frameWidth = 0
+    act(() => { fireResize?.(); vi.advanceTimersByTime(20) })
+    // Track template still reflects the last non-zero viewport.
+    expect(tracks(frame)).toEqual([300, 360])
+  })
+})
+
+describe('AppFrame — unmount with an in-flight resize frame', () => {
+  it('cancels the pending rAF on unmount (no post-unmount setState)', () => {
+    const { unmount } = mountFrame()
+    frameWidth = 800
+    act(() => { fireResize?.() }) // rAF scheduled, NOT flushed
+    unmount()
+    // Flushing after unmount must be a no-op (the frame was cancelled).
+    expect(() => { vi.advanceTimersByTime(20) }).not.toThrow()
+  })
+
+  it('double resize inside one frame rides the pending rAF (?"?= guard)', () => {
+    const { frame } = mountFrame()
+    frameWidth = 1250
+    act(() => { fireResize?.(); fireResize?.(); vi.advanceTimersByTime(20) })
+    expect(tracks(frame)).toEqual([300, 310])
+  })
+})

packages/client/ui-layout/tests/apply.spec.ts

@@ -0,0 +1,73 @@
+// @vitest-environment jsdom
+// Client apply wiring: ctx.layout provided, the four layout-owned slots
+// defined, teardown cascades (service unprovided + slot specs removed + list
+// subscription dropped). Node half and the invariant companion ride along —
+// they are one-line surfaces the aggregate coverage gate still requires
+// exercised.
+
+import { Context } from 'cordis'
+import { describe, expect, it, vi } from 'vitest'
+import { createSnapshotStore } from '@deepseek-ai/dsh-client-web-react'
+import { SlotsService } from '@deepseek-ai/dsh-client-runtime/client'
+import type { SessionListState } from '@deepseek-ai/dsh-client-runtime/client'
+import { apply, inject, LayoutService } from '@deepseek-ai/dsh-client-ui-layout/client'
+import { apply as nodeApply } from '@deepseek-ai/dsh-client-ui-layout'
+import * as invariant from '@deepseek-ai/dsh-client-ui-layout/invariant'
+
+async function bench() {
+  const ctx = new Context()
+  const slotsFiber = ctx.plugin(SlotsService)
+  await slotsFiber.await()
+  const list = createSnapshotStore<SessionListState>({ ids: [], byId: {} })
+  ctx.provide('sessions', { list })
+  return { ctx, slots: ctx.get('slots') as SlotsService }
+}
+
+describe('ui-layout client apply', () => {
+  it('declares its service dependencies', () => {
+    expect(inject).toContain('slots')
+  })
+
+  it('provides ctx.layout and defines the four layout-owned slots', async () => {
+    const { ctx, slots } = await bench()
+    const fiber = ctx.plugin({ inject: ['slots'], apply })
+    await fiber.await()
+    expect(ctx.get('layout')).toBeInstanceOf(LayoutService)
+    expect(slots.spec('sidebar')).toEqual({ kind: 'single', scope: 'root' })
+    expect(slots.spec('conversation')).toEqual({ kind: 'single', scope: 'session' })
+    expect(slots.spec('details')).toEqual({ kind: 'single', scope: 'session' })
+    expect(slots.spec('conversation.empty')).toEqual({ kind: 'single', scope: 'root' })
+  })
+
+  it('teardown unwinds service, slot specs, and the prune subscription', async () => {
+    const { ctx, slots } = await bench()
+    const fiber = ctx.plugin({ inject: ['slots'], apply })
+    await fiber.await()
+    const layout = ctx.get('layout') as LayoutService
+    const disposeSpy = vi.spyOn(layout, 'dispose')
+    await fiber.dispose()
+    expect(ctx.get('layout')).toBeUndefined()
+    expect(slots.spec('sidebar')).toBeUndefined()
+    expect(slots.spec('conversation.empty')).toBeUndefined()
+    expect(disposeSpy).toHaveBeenCalledTimes(1)
+  })
+})
+
+describe('node half + invariant companion', () => {
+  it('node apply is an intentional no-op (loader-managed lifecycle only)', () => {
+    nodeApply()
+    expect(true).toBe(true) // reaching here without throw is the contract
+  })
+
+  it('invariant companion registers under the package name', async () => {
+    const register = vi.fn().mockReturnValue(() => {})
+    const ctx = { invariants: { register } } as never
+    // The /invariant subpath types live in lib/types (build product); assert
+    // the surface so the call stays typed where lint runs without a build.
+    const dispose = await (invariant as { apply: (ctx: never) => Promise<() => void> }).apply(ctx)
+    expect(register).toHaveBeenCalledWith('@deepseek-ai/dsh-client-ui-layout', expect.any(Function))
+    // The installer is the declared no-op — calling it must not throw.
+    expect(() => { (register.mock.calls[0]![1] as (c: never) => void)(undefined as never) }).not.toThrow()
+    expect(dispose).toBeTypeOf('function')
+  })
+})

packages/client/ui-layout/tests/columns.spec.ts

@@ -0,0 +1,100 @@
+import { describe, expect, it } from 'vitest'
+import {
+  CENTER_MIN, clampWidth, computeColumns,
+  DETAILS_DEFAULT, DETAILS_MIN, SIDEBAR_DEFAULT, SIDEBAR_MIN,
+} from '@deepseek-ai/dsh-client-ui-layout/client'
+
+const open = (width: number) => ({ open: true, width })
+const closed = (width: number) => ({ open: false, width })
+
+describe('clampWidth', () => {
+  it('clamps into the range and rounds', () => {
+    expect(clampWidth(250.4, 240, 420)).toBe(250)
+    expect(clampWidth(100, 240, 420)).toBe(240)
+    expect(clampWidth(9999, 240, 420)).toBe(420)
+  })
+})
+
+describe('computeColumns', () => {
+  it('step 1: everything fits at preferred widths', () => {
+    const cols = computeColumns(1920, open(SIDEBAR_DEFAULT), open(DETAILS_DEFAULT))
+    expect(cols).toEqual({ sidebar: 300, center: 1920 - 300 - 360, details: 360 })
+  })
+
+  it('closed panels contribute zero width', () => {
+    expect(computeColumns(1920, closed(300), closed(360))).toEqual({ sidebar: 0, center: 1920, details: 0 })
+  })
+
+  it('preferences beyond the clamp range are clamped before solving', () => {
+    const cols = computeColumns(1920, open(9999), open(1))
+    expect(cols.sidebar).toBe(420)
+    expect(cols.details).toBe(300)
+  })
+
+  it('step 2: details shrinks first, center pinned at min', () => {
+    // 300 + 360 + 640 = 1300 > 1250; details concedes to 1250-300-640 = 310.
+    const cols = computeColumns(1250, open(SIDEBAR_DEFAULT), open(DETAILS_DEFAULT))
+    expect(cols).toEqual({ sidebar: 300, center: CENTER_MIN, details: 310 })
+  })
+
+  it('boundary: exactly at the step-1/step-2 seam', () => {
+    const cols = computeColumns(300 + 360 + CENTER_MIN, open(300), open(360))
+    expect(cols).toEqual({ sidebar: 300, center: CENTER_MIN, details: 360 })
+    const one = computeColumns(300 + 360 + CENTER_MIN - 1, open(300), open(360))
+    expect(one).toEqual({ sidebar: 300, center: CENTER_MIN, details: 359 })
+  })
+
+  it('step 3: sidebar concedes after details hits its min', () => {
+    // details floor 300: sidebar = 1220-300-640 = 280.
+    const cols = computeColumns(1220, open(SIDEBAR_DEFAULT), open(DETAILS_DEFAULT))
+    expect(cols).toEqual({ sidebar: 280, center: CENTER_MIN, details: DETAILS_MIN })
+  })
+
+  it('step 4: details auto-closes when both panels are at min and center still starves', () => {
+    // 240 + 300 + 640 = 1180 > 1100 → details 0; sidebar preference (300) fits: 1100-300 = 800 center.
+    const cols = computeColumns(1100, open(SIDEBAR_DEFAULT), open(DETAILS_DEFAULT))
+    expect(cols).toEqual({ sidebar: 300, center: 800, details: 0 })
+  })
+
+  it('step 4 keeps squeezing sidebar when preference no longer fits', () => {
+    // 900 < 300+640: sidebar = max(240, 900-640) = 260.
+    const cols = computeColumns(900, open(SIDEBAR_DEFAULT), open(DETAILS_DEFAULT))
+    expect(cols).toEqual({ sidebar: 260, center: CENTER_MIN, details: 0 })
+  })
+
+  it('step 5: center absorbs the deficit as last resort (details closed)', () => {
+    // 700 < 240+640: sidebar floors at 240, center takes 460 < CENTER_MIN.
+    const cols = computeColumns(700, open(SIDEBAR_DEFAULT), closed(DETAILS_DEFAULT))
+    expect(cols).toEqual({ sidebar: SIDEBAR_MIN, center: 460, details: 0 })
+  })
+
+  it('sidebar-closed narrow window: details concedes then auto-closes', () => {
+    const fits = computeColumns(DETAILS_MIN + CENTER_MIN, closed(300), open(DETAILS_DEFAULT))
+    expect(fits).toEqual({ sidebar: 0, center: CENTER_MIN, details: DETAILS_MIN })
+    const starved = computeColumns(DETAILS_MIN + CENTER_MIN - 1, closed(300), open(DETAILS_DEFAULT))
+    expect(starved).toEqual({ sidebar: 0, center: DETAILS_MIN + CENTER_MIN - 1, details: 0 })
+  })
+
+  it('tiny viewport: both panels yield everything to center', () => {
+    const cols = computeColumns(400, open(SIDEBAR_DEFAULT), open(DETAILS_DEFAULT))
+    expect(cols.details).toBe(0)
+    expect(cols.sidebar).toBe(SIDEBAR_MIN)
+    expect(cols.center).toBe(Math.max(0, 400 - SIDEBAR_MIN))
+  })
+
+  it('recovery is pure: re-widening restores preferred widths untouched', () => {
+    const squeezed = computeColumns(1100, open(SIDEBAR_DEFAULT), open(DETAILS_DEFAULT))
+    expect(squeezed.details).toBe(0)
+    const restored = computeColumns(1920, open(SIDEBAR_DEFAULT), open(DETAILS_DEFAULT))
+    expect(restored.details).toBe(DETAILS_DEFAULT)
+    expect(restored.sidebar).toBe(SIDEBAR_DEFAULT)
+  })
+})
+
+describe('computeColumns — degenerate viewports', () => {
+  it('sidebar closed and viewport below CENTER_MIN: details auto-closes, center takes all', () => {
+    // Reaches step 4's re-solve with s0 = 0 (the closed-sidebar arm).
+    expect(computeColumns(500, closed(300), open(DETAILS_DEFAULT)))
+      .toEqual({ sidebar: 0, center: 500, details: 0 })
+  })
+})

packages/client/ui-layout/tests/service.spec.ts

@@ -0,0 +1,138 @@
+// @vitest-environment jsdom
+/**
+ * LayoutService over the real snapshot-store engine (persist rides jsdom
+ * localStorage). ctx is faked down to the one surface the service reads:
+ * ctx.sessions.list as a real store, so prune subscriptions are exercised
+ * for real.
+ */
+import { beforeEach, describe, expect, it } from 'vitest'
+import type { Context } from 'cordis'
+import { createSnapshotStore } from '@deepseek-ai/dsh-client-web-react'
+import type { SessionId, SessionListState } from '@deepseek-ai/dsh-client-runtime/client'
+import { LayoutService, DETAILS_DEFAULT, SIDEBAR_DEFAULT } from '@deepseek-ai/dsh-client-ui-layout/client'
+
+function makeCtx() {
+  const list = createSnapshotStore<SessionListState>({ ids: [], byId: {} })
+  // The service resolves sessions via ctx.get (typed merge suspended, see service).
+  const ctx = { get: (name: string) => (name === 'sessions' ? { list } : undefined) } as unknown as Context
+  return { ctx, list }
+}
+
+/** Test-side brand: specs mint ids the wire would normally brand. */
+const sid = (s: string): SessionId => s as SessionId
+const summary = (id: SessionId) => ({ id, title: id as string, running: false, updatedAt: 1 })
+
+beforeEach(() => { localStorage.clear() })
+
+describe('LayoutService', () => {
+  it('defaults: sidebar open 300, details closed 360, empty nav', () => {
+    const svc = new LayoutService(makeCtx().ctx)
+    expect(svc.sidebar.getSnapshot()).toEqual({ open: true, width: SIDEBAR_DEFAULT })
+    expect(svc.details.getSnapshot()).toEqual({ open: false, width: DETAILS_DEFAULT })
+    expect(svc.current.getSnapshot()).toEqual({ viewFor: {} })
+    svc.dispose()
+  })
+
+  it('open validates against sessions.list and selects', () => {
+    const { ctx, list } = makeCtx()
+    const svc = new LayoutService(ctx)
+    expect(() => { svc.open(sid('nope')) }).toThrow(/unknown session/)
+    list.update((d) => { d.ids.push(sid('s1')); d.byId[sid('s1')] = summary(sid('s1')) })
+    svc.open(sid('s1'))
+    expect(svc.current.getSnapshot().sessionId).toBe('s1')
+    svc.dispose()
+  })
+
+  it('width setters clamp into contract ranges', () => {
+    const svc = new LayoutService(makeCtx().ctx)
+    svc.setSidebarWidth(10)
+    expect(svc.sidebar.getSnapshot().width).toBe(240)
+    svc.setSidebarWidth(10_000)
+    expect(svc.sidebar.getSnapshot().width).toBe(420)
+    svc.setDetailsWidth(10)
+    expect(svc.details.getSnapshot().width).toBe(300)
+    svc.setDetailsWidth(10_000)
+    expect(svc.details.getSnapshot().width).toBe(520)
+    svc.dispose()
+  })
+
+  it('toggle and open/close flip flags without touching widths', () => {
+    const svc = new LayoutService(makeCtx().ctx)
+    svc.toggleSidebar()
+    expect(svc.sidebar.getSnapshot()).toEqual({ open: false, width: SIDEBAR_DEFAULT })
+    svc.openDetails()
+    expect(svc.details.getSnapshot().open).toBe(true)
+    svc.closeDetails()
+    expect(svc.details.getSnapshot().open).toBe(false)
+    svc.dispose()
+  })
+
+  it('prune clears viewFor entries and the current selection of removed sessions', () => {
+    const { ctx, list } = makeCtx()
+    const svc = new LayoutService(ctx)
+    list.update((d) => {
+      d.ids.push(sid('s1'), sid('s2'))
+      d.byId[sid('s1')] = summary(sid('s1'))
+      d.byId[sid('s2')] = summary(sid('s2'))
+    })
+    svc.open(sid('s1'))
+    svc.openView(sid('s1'), 'chat')
+    svc.openView(sid('s2'), 'chat')
+    list.update((d) => { d.ids = [sid('s2')]; d.byId = { [sid('s2')]: d.byId[sid('s2')]! } })
+    expect(svc.current.getSnapshot().sessionId).toBeUndefined()
+    expect(svc.current.getSnapshot().viewFor).toEqual({ s2: 'chat' })
+    svc.dispose()
+  })
+
+  it('prune leaves untouched state alone (no gratuitous store writes)', () => {
+    const { ctx, list } = makeCtx()
+    const svc = new LayoutService(ctx)
+    list.update((d) => { d.ids.push(sid('s1')); d.byId[sid('s1')] = summary(sid('s1')) })
+    svc.open(sid('s1'))
+    const before = svc.current.getSnapshot()
+    list.update((d) => { d.byId[sid('s1')] = { ...d.byId[sid('s1')]!, title: 'renamed' } })
+    expect(svc.current.getSnapshot()).toBe(before)
+    svc.dispose()
+  })
+
+  it('persists panel state and nav across instances (fresh service, same storage)', () => {
+    const first = new LayoutService(makeCtx().ctx)
+    first.setSidebarWidth(320)
+    first.openDetails()
+    first.dispose()
+    const second = new LayoutService(makeCtx().ctx)
+    expect(second.sidebar.getSnapshot().width).toBe(320)
+    expect(second.details.getSnapshot().open).toBe(true)
+    second.dispose()
+  })
+
+  it('dispose stops pruning', () => {
+    const { ctx, list } = makeCtx()
+    const svc = new LayoutService(ctx)
+    list.update((d) => { d.ids.push(sid('s1')); d.byId[sid('s1')] = summary(sid('s1')) })
+    svc.open(sid('s1'))
+    svc.dispose()
+    list.update((d) => { d.ids = []; d.byId = {} })
+    expect(svc.current.getSnapshot().sessionId).toBe('s1')
+  })
+})
+
+describe('LayoutService — construction and prune edge branches', () => {
+  it('throws loud when the sessions service is absent', () => {
+    const bare = { get: () => undefined } as unknown as Context
+    expect(() => new LayoutService(bare)).toThrow(/sessions service unavailable/)
+  })
+
+  it('prunes stale viewFor while the current selection stays valid', () => {
+    // Covers the prune branch where staleView holds but staleCurrent does not.
+    const { ctx, list } = makeCtx()
+    const svc = new LayoutService(ctx)
+    list.update((d) => { d.ids.push(sid('s1'), sid('s2')); d.byId[sid('s1')] = summary(sid('s1')); d.byId[sid('s2')] = summary(sid('s2')) })
+    svc.open(sid('s1'))
+    svc.openView(sid('s2'), 'chat')
+    list.update((d) => { d.ids = [sid('s1')]; d.byId = { [sid('s1')]: d.byId[sid('s1')]! } })
+    expect(svc.current.getSnapshot().sessionId).toBe('s1')
+    expect(svc.current.getSnapshot().viewFor).toEqual({})
+    svc.dispose()
+  })
+})