Stabilize active-delete proof timing

tests/e2e/helpers/orca-app.ts

@@ -47,6 +47,8 @@ type OrcaTestFixtures = {
   // Why: most E2E specs need a ready project before assertions start. Golden
   // first-run specs opt out so they can prove the zero-project onboarding path.
   seedTestRepo: boolean
+  // Synthetic-list specs need only the primary checkout; switching specs keep the two-row default.
+  minimumSeededWorktreeCount: number
   // Why: spec-scoped launch env. Mutating process.env at spec module scope
   // leaks into other specs when a worker reloads files without replaying the
   // first spec's afterAll; per-test launch env cannot leak.
@@ -273,13 +275,17 @@ export const test = base.extend<OrcaTestFixtures, OrcaWorkerFixtures>({
   // Default: dismiss the onboarding overlay so it doesn't intercept clicks.
   dismissOnboarding: [true, { option: true }],
   seedTestRepo: [true, { option: true }],
+  minimumSeededWorktreeCount: [2, { option: true }],
   launchEnv: [{}, { option: true }],
   orcaAppExtraEnv: [{}, { option: true }],
   orcaAppExtraArgs: [[], { option: true }],
 
   // Test-scoped: grab the first BrowserWindow, add the test repo, and wait
   // until the session is fully ready with a worktree active.
-  sharedPage: async ({ electronApp, seedTestRepo, testRepoPath }, provideFixture) => {
+  sharedPage: async (
+    { electronApp, minimumSeededWorktreeCount, seedTestRepo, testRepoPath },
+    provideFixture
+  ) => {
     // Why: the Electron app may take a while to create the first window,
     // especially on cold start with no prior dev userData. Isolated per-test
     // profiles make late-suite launches slower, so use the full test budget.
@@ -379,7 +385,7 @@ export const test = base.extend<OrcaTestFixtures, OrcaWorkerFixtures>({
           message: 'seeded e2e worktrees did not load'
         }
       )
-      .toBeGreaterThanOrEqual(2)
+      .toBeGreaterThanOrEqual(minimumSeededWorktreeCount)
 
     // Wait for workspaceSessionReady to become true
     await page.waitForFunction(

tests/e2e/worktree-active-delete-scroll-position.spec.ts

@@ -8,6 +8,8 @@ const VISUAL_PROOF_PAUSE_MS = 1_200
 const POST_REMOVAL_SAMPLE_FRAMES = 20
 const MAX_REMOVAL_WAIT_FRAMES = 300
 
+test.use({ minimumSeededWorktreeCount: 1 })
+
 type RowRemovalFrame = {
   animationCount: number
   belowTop: number | null
@@ -126,7 +128,7 @@ async function seedActiveDeletionRows(page: Page): Promise<{
   )
 }
 
-async function prepareScrolledActiveRow(page: Page, targetId: string): Promise<number> {
+async function prepareScrolledActiveRow(page: Page, targetId: string): Promise<void> {
   const target = page.locator(
     `[data-worktree-sidebar] [data-worktree-id=${JSON.stringify(targetId)}]`
   )
@@ -158,7 +160,6 @@ async function prepareScrolledActiveRow(page: Page, targetId: string): Promise<n
   })
   await expect(target).toBeVisible()
   await expect(target).toHaveAttribute('aria-current', 'page')
-  return scroller.evaluate((element) => element.scrollTop)
 }
 
 async function startRowRemovalSampling(
@@ -169,10 +170,7 @@ async function startRowRemovalSampling(
   await page.evaluate(
     ({ belowId, maxRemovalWaitFrames, postRemovalSampleFrames, targetId }) => {
       const sample = async (): Promise<RowRemovalFrame[]> => {
-        const frames: RowRemovalFrame[] = []
-        let framesAfterRemoval = 0
-        for (let index = 0; index < maxRemovalWaitFrames + postRemovalSampleFrames; index += 1) {
-          await new Promise<void>((resolve) => requestAnimationFrame(() => resolve()))
+        const readFrame = (): RowRemovalFrame => {
           const scroller = document.querySelector<HTMLElement>('[data-worktree-sidebar]')
           const below = document.querySelector<HTMLElement>(
             `[data-worktree-sidebar] [data-worktree-id=${JSON.stringify(belowId)}]`
@@ -182,16 +180,22 @@ async function startRowRemovalSampling(
               `[data-worktree-sidebar] [data-worktree-id=${JSON.stringify(targetId)}]`
             )
           )
-          const animationCount =
-            below?.closest('[data-worktree-virtual-row]')?.firstElementChild?.getAnimations()
-              .length ?? 0
-          frames.push({
-            animationCount,
+          return {
+            animationCount:
+              below?.closest('[data-worktree-virtual-row]')?.firstElementChild?.getAnimations()
+                .length ?? 0,
             belowTop: below?.getBoundingClientRect().top ?? null,
             scrollTop: scroller?.scrollTop ?? 0,
             targetExists
-          })
-          framesAfterRemoval = targetExists ? 0 : framesAfterRemoval + 1
+          }
+        }
+        const frames: RowRemovalFrame[] = [readFrame()]
+        let framesAfterRemoval = 0
+        for (let index = 0; index < maxRemovalWaitFrames + postRemovalSampleFrames; index += 1) {
+          await new Promise<void>((resolve) => requestAnimationFrame(() => resolve()))
+          const frame = readFrame()
+          frames.push(frame)
+          framesAfterRemoval = frame.targetExists ? 0 : framesAfterRemoval + 1
           if (framesAfterRemoval >= postRemovalSampleFrames) {
             break
           }
@@ -225,7 +229,7 @@ test('deleting the active scrolled worktree preserves position and closes the ro
   await waitForSessionReady(orcaPage)
   await orcaPage.setViewportSize({ width: 1_200, height: 800 })
   const { belowId, successorId, targetId } = await seedActiveDeletionRows(orcaPage)
-  const initialScrollTop = await prepareScrolledActiveRow(orcaPage, targetId)
+  await prepareScrolledActiveRow(orcaPage, targetId)
   const target = orcaPage.locator(
     `[data-worktree-sidebar] [data-worktree-id=${JSON.stringify(targetId)}]`
   )
@@ -266,16 +270,20 @@ test('deleting the active scrolled worktree preserves position and closes the ro
   await pauseForVisualProof(orcaPage)
   const mountedTops = frames.flatMap((frame) => (frame.belowTop === null ? [] : [frame.belowTop]))
   const firstRemovedFrame = frames.findIndex((frame) => !frame.targetExists)
+  const scrollTopBeforeDelete = frames[0]?.scrollTop
+  if (scrollTopBeforeDelete === undefined) {
+    throw new Error('Row removal sampler recorded no pre-delete frame')
+  }
 
   expect(firstRemovedFrame).toBeGreaterThan(0)
   expect(frames.slice(firstRemovedFrame).every((frame) => !frame.targetExists)).toBe(true)
   expect(Math.max(...frames.map((frame) => frame.animationCount))).toBeGreaterThan(0)
   expect(Math.max(...mountedTops) - Math.min(...mountedTops)).toBeGreaterThan(30)
   expect(Math.max(...frames.map((frame) => frame.scrollTop))).toBeLessThanOrEqual(
-    initialScrollTop + 1
+    scrollTopBeforeDelete + 1
   )
   expect(Math.min(...frames.map((frame) => frame.scrollTop))).toBeGreaterThanOrEqual(
-    initialScrollTop - 1
+    scrollTopBeforeDelete - 1
   )
   await expect(
     orcaPage.locator(`[data-worktree-sidebar] [data-worktree-id=${JSON.stringify(successorId)}]`)