feat(app): stabilize long session timelines

bunfig.toml

@@ -2,7 +2,7 @@
 exact = true
 # Only install newly resolved package versions published at least 3 days ago.
 minimumReleaseAge = 259200
-minimumReleaseAgeExcludes = ["@ai-sdk/amazon-bedrock", "@ai-sdk/anthropic", "@opentui/core", "@opentui/core-darwin-arm64", "@opentui/core-darwin-x64", "@opentui/core-linux-arm64", "@opentui/core-linux-arm64-musl", "@opentui/core-linux-x64", "@opentui/core-linux-x64-musl", "@opentui/core-win32-arm64", "@opentui/core-win32-x64", "@opentui/keymap", "@opentui/solid", "opentui-spinner", "gitlab-ai-provider", "opencode-gitlab-auth", "@ff-labs/fff-node", "@ff-labs/fff-bun", "@ff-labs/fff-bin-darwin-arm64", "@ff-labs/fff-bin-darwin-x64", "@ff-labs/fff-bin-linux-arm64-gnu", "@ff-labs/fff-bin-linux-arm64-musl", "@ff-labs/fff-bin-linux-x64-gnu", "@ff-labs/fff-bin-linux-x64-musl", "@ff-labs/fff-bin-win32-arm64", "@ff-labs/fff-bin-win32-x64", "app-builder-lib", "dmg-builder", "electron-builder", "electron-publish"]
+minimumReleaseAgeExcludes = ["@ai-sdk/amazon-bedrock", "@ai-sdk/anthropic", "@opentui/core", "@opentui/core-darwin-arm64", "@opentui/core-darwin-x64", "@opentui/core-linux-arm64", "@opentui/core-linux-arm64-musl", "@opentui/core-linux-x64", "@opentui/core-linux-x64-musl", "@opentui/core-win32-arm64", "@opentui/core-win32-x64", "@opentui/keymap", "@opentui/solid", "opentui-spinner", "gitlab-ai-provider", "opencode-gitlab-auth", "@ff-labs/fff-node", "@ff-labs/fff-bun", "@ff-labs/fff-bin-darwin-arm64", "@ff-labs/fff-bin-darwin-x64", "@ff-labs/fff-bin-linux-arm64-gnu", "@ff-labs/fff-bin-linux-arm64-musl", "@ff-labs/fff-bin-linux-x64-gnu", "@ff-labs/fff-bin-linux-x64-musl", "@ff-labs/fff-bin-win32-arm64", "@ff-labs/fff-bin-win32-x64", "@pierre/diffs", "@pierre/theming", "app-builder-lib", "dmg-builder", "electron-builder", "electron-publish"]
 
 [test]
 root = "./do-not-run-tests-from-root"

package.json

@@ -42,6 +42,8 @@
       "@opentui/core": "0.3.4",
       "@opentui/keymap": "0.3.4",
       "@opentui/solid": "0.3.4",
+      "@tanstack/solid-virtual": "3.13.28",
+      "@shikijs/stream": "4.2.0",
       "ulid": "3.0.1",
       "@kobalte/core": "0.13.11",
       "@types/luxon": "3.7.1",
@@ -51,7 +53,7 @@
       "@tsconfig/bun": "1.0.9",
       "@cloudflare/workers-types": "4.20251008.0",
       "@openauthjs/openauth": "0.0.0-20250322224806",
-      "@pierre/diffs": "1.1.0-beta.18",
+      "@pierre/diffs": "1.2.10",
       "opentui-spinner": "0.0.7",
       "@solid-primitives/storage": "4.3.3",
       "@tailwindcss/vite": "4.1.11",
@@ -76,10 +78,9 @@
       "zod": "4.1.8",
       "remeda": "2.26.0",
       "sst": "4.13.1",
-      "shiki": "3.20.0",
+      "shiki": "4.2.0",
       "solid-list": "0.3.0",
       "tailwindcss": "4.1.11",
-      "virtua": "0.49.1",
       "vite": "7.1.4",
       "@solidjs/meta": "0.29.4",
       "@solidjs/router": "0.15.4",
@@ -145,11 +146,12 @@
     "@silvia-odwyer/photon-node@0.3.4": "patches/@silvia-odwyer%2Fphoton-node@0.3.4.patch",
     "@standard-community/standard-openapi@0.2.9": "patches/@standard-community%2Fstandard-openapi@0.2.9.patch",
     "solid-js@1.9.10": "patches/solid-js@1.9.10.patch",
-    "virtua@0.49.1": "patches/virtua@0.49.1.patch",
     "@ai-sdk/xai@3.0.82": "patches/@ai-sdk%2Fxai@3.0.82.patch",
     "gcp-metadata@8.1.2": "patches/gcp-metadata@8.1.2.patch",
     "pacote@21.5.0": "patches/pacote@21.5.0.patch",
     "@ai-sdk/google@3.0.73": "patches/@ai-sdk%2Fgoogle@3.0.73.patch",
-    "@modelcontextprotocol/sdk@1.29.0": "patches/@modelcontextprotocol%2Fsdk@1.29.0.patch"
+    "@tanstack/solid-virtual@3.13.28": "patches/@tanstack%2Fsolid-virtual@3.13.28.patch",
+    "@modelcontextprotocol/sdk@1.29.0": "patches/@modelcontextprotocol%2Fsdk@1.29.0.patch",
+    "@tanstack/virtual-core@3.17.0": "patches/@tanstack%2Fvirtual-core@3.17.0.patch"
   }
 }

packages/app/e2e/regression/session-timeline-collapse-state.spec.ts

@@ -147,7 +147,8 @@ test.describe("regression: session timeline local row state", () => {
 
     const wrapper = page.locator(`[data-timeline-part-id="${editPartID}"]`).first()
     await expectAppVisible(wrapper)
-    await expectAppVisible(wrapper.locator('[data-component="file"][data-mode="diff"]').first())
+    const file = wrapper.locator('[data-component="file"][data-mode="diff"]').first()
+    await expectAppVisible(file)
     await markDiffProbe(page)
 
     events.push({
@@ -159,7 +160,15 @@ test.describe("regression: session timeline local row state", () => {
     })
 
     await expect(page.locator(`[data-timeline-part-id="${textPartID}"]`).first()).toBeVisible({ timeout: 10_000 })
-    expect(await readDiffProbe(page)).toEqual({ fileMarker: "before", shadowRoots: 0, toolMarker: "before" })
+    const siblingProbe = await readDiffProbe(page)
+    expect(siblingProbe).toEqual({
+      fileMarker: "before",
+      frameMarker: "before",
+      rowKey: `assistant-part:${userMessageID}:part:${assistantMessageID}:${editPartID}`,
+      rowMarker: "before",
+      shadowRoots: 0,
+      toolMarker: "before",
+    })
 
     await markDiffProbe(page)
     events.push({
@@ -173,7 +182,72 @@ test.describe("regression: session timeline local row state", () => {
     await expect(wrapper.locator('[data-slot="diff-changes-additions"]').filter({ hasText: "+2" }).first()).toBeVisible(
       { timeout: 10_000 },
     )
-    expect(await readDiffProbe(page)).toEqual({ fileMarker: "before", shadowRoots: 0, toolMarker: "before" })
+    expect(await readDiffProbe(page)).toEqual({
+      fileMarker: "before",
+      frameMarker: "before",
+      rowKey: `assistant-part:${userMessageID}:part:${assistantMessageID}:${editPartID}`,
+      rowMarker: "before",
+      shadowRoots: 0,
+      toolMarker: "before",
+    })
+  })
+
+  test("keeps a sticky edit header aligned with a multi-hunk diff", async ({ page }) => {
+    const events: EventPayload[] = []
+    const lines = Array.from({ length: 1_000 }, (_, index) => `export const value${index} = ${index}\n`).join("")
+    const after = [100, 300, 500, 700, 900].reduce(
+      (result, index) => result.replace(`export const value${index} = ${index}`, `export const value${index} = compute(${index})`),
+      lines,
+    )
+    const part = {
+      ...editPart,
+      state: {
+        ...editPart.state,
+        metadata: {
+          ...editPart.state.metadata,
+          filediff: {
+            file: "src/regression.ts",
+            additions: 1,
+            deletions: 1,
+            before: lines,
+            after,
+          },
+        },
+      },
+    }
+    await mockServer(page, events, [userMessage, { ...assistantMessage, parts: [part] }])
+    await configurePage(page)
+
+    await page.goto(`/${base64Encode(directory)}/session/${sessionID}`)
+    await expectSessionTitle(page, title)
+
+    const wrapper = page.locator(`[data-timeline-part-id="${editPartID}"]`).first()
+    const trigger = wrapper.locator('[data-slot="collapsible-trigger"]').first()
+    const diff = wrapper.locator('[data-component="edit-content"]').first()
+    await expectAppVisible(diff)
+    await expect.poll(() => wrapper.evaluate((element) => element.getBoundingClientRect().height)).toBeGreaterThan(500)
+    const samples = await wrapper.evaluate(async (element) => {
+      const root = element.closest<HTMLElement>(".scroll-view__viewport")!
+      element.scrollIntoView({ block: "start" })
+      const result = []
+      for (const offset of [0, 120, 240, 360, 480]) {
+        root.scrollBy(0, offset - (result.at(-1)?.offset ?? 0))
+        await new Promise(requestAnimationFrame)
+        const trigger = element.querySelector<HTMLElement>('[data-slot="collapsible-trigger"]')!
+        const diff = element.querySelector<HTMLElement>('[data-component="edit-content"]')!
+        result.push({
+          offset,
+          trigger: trigger.getBoundingClientRect().y,
+          diff: diff.getBoundingClientRect().y,
+          bottom: element.getBoundingClientRect().bottom,
+        })
+      }
+      return result
+    })
+
+    expect(samples[0]!.trigger).toBeLessThan(samples[0]!.diff)
+    expect(samples.every((sample) => Math.abs(sample.trigger - samples[0]!.trigger) <= 1)).toBe(true)
+    expect(samples.every((sample) => sample.trigger < sample.bottom)).toBe(true)
   })
 })
 
@@ -247,10 +321,16 @@ async function markDiffProbe(page: Page) {
     .evaluate((element) => {
       const tool = element as HTMLElement
       const file = tool.querySelector<HTMLElement>('[data-component="file"][data-mode="diff"]')
+      const row = tool.closest<HTMLElement>("[data-timeline-key]")
+      const frame = tool.closest<HTMLElement>("[data-timeline-row]")
       if (!file) throw new Error("missing edit diff file")
+      if (!row) throw new Error("missing virtual timeline row")
+      if (!frame) throw new Error("missing timeline row frame")
 
       tool.dataset.timelineProbe = "before"
       file.dataset.timelineProbe = "before"
+      row.dataset.timelineProbe = "before"
+      frame.dataset.timelineProbe = "before"
       window.__timelineDiffProbe.reset()
     })
 }
@@ -262,10 +342,15 @@ async function readDiffProbe(page: Page) {
     .evaluate((element) => {
       const tool = element as HTMLElement
       const file = tool.querySelector<HTMLElement>('[data-component="file"][data-mode="diff"]')
+      const row = tool.closest<HTMLElement>("[data-timeline-key]")
+      const frame = tool.closest<HTMLElement>("[data-timeline-row]")
       return {
         fileMarker: file?.dataset.timelineProbe,
         shadowRoots: window.__timelineDiffProbe.shadowRoots(),
         toolMarker: tool.dataset.timelineProbe,
+        rowMarker: row?.dataset.timelineProbe,
+        rowKey: row?.dataset.timelineKey,
+        frameMarker: frame?.dataset.timelineProbe,
       }
     })
 }
@@ -300,14 +385,19 @@ function readExpanded(element: Element) {
   return !!content && content.getBoundingClientRect().height > 0
 }
 
-async function mockServer(page: Page, events: EventPayload[]) {
+async function mockServer(
+  page: Page,
+  events: EventPayload[],
+  messages = [userMessage, assistantMessage],
+) {
   await mockOpenCodeServer(page, {
     directory,
     project: project(),
     provider: provider(),
     sessions: [session()],
-    pageMessages: () => ({ items: [userMessage, assistantMessage] }),
-    events: () => events.splice(0),
+    pageMessages: () => ({ items: messages }),
+    events: () => events.splice(0, 1),
+    eventRetry: 16,
   })
 }
 

packages/app/e2e/regression/session-timeline-context-resize.spec.ts

@@ -32,8 +32,6 @@ test.describe("regression: session timeline context group resize", () => {
     const samples = await sampleExpansion(page)
     const visibleOverlap = samples.filter((sample) => sample.frame >= 1 && sample.overlap > 0.5)
 
-    console.log("context resize samples", JSON.stringify(samples, null, 2))
-
     expect(samples[0]?.overlap).toBe(0)
     expect(visibleOverlap).toEqual([])
     expect(samples.at(-1)?.expanded).toBe("true")
@@ -115,13 +113,15 @@ async function sampleExpansion(page: Page) {
 
         let frame = 1
         const tick = () => {
-          capture(frame, "raf")
-          frame += 1
-          if (frame > 8) {
-            resolve(samples)
-            return
-          }
-          requestAnimationFrame(tick)
+          setTimeout(() => {
+            capture(frame, "painted")
+            frame += 1
+            if (frame > 8) {
+              resolve(samples)
+              return
+            }
+            requestAnimationFrame(tick)
+          }, 0)
         }
         requestAnimationFrame(tick)
       }),