fix(app): make session navigation stable and fast (#33569)

Co-authored-by: Brendan Allan <git@brendonovich.dev>
2026-06-24 07:48:54 +00:00
parent abcfeb380b
commit a4551a94b4
29 changed files with 1028 additions and 202 deletions
@@ -0,0 +1,87 @@
+import { expectSessionTitle } from "../../utils/waits"
+import { benchmark, expect } from "../benchmark"
+import { measureFirstNavigation } from "./first-navigation-probe"
+import { fixture } from "./session-timeline-stress.fixture"
+import {
+  installStressSessionTabs,
+  installTimelineSettings,
+  mockStressTimeline,
+  stressDraftHref,
+  stressSessionHref,
+} from "./timeline-test-helpers"
+import { waitForStableTimeline } from "./session-tab-switch-probe"
+
+const contentSelector = '[data-message-id], [data-component="prompt-input"]'
+const draftID = "draft_first_navigation"
+
+benchmark.describe("performance: first navigation paint", () => {
+  benchmark("opens an unvisited session tab without a blank frame", async ({ page, report }) => {
+    await setup(page)
+    const href = stressSessionHref(fixture.targetID)
+    const result = await measureFirstNavigation(page, {
+      href,
+      destinationPath: href,
+      sourceSelector: messageSelector(fixture.expected.sourceMessageIDs.at(-1)!),
+      destinationSelector: messageSelector(fixture.expected.targetMessageIDs.at(-1)!),
+      contentSelector,
+      navigate: async () => {
+        await page.locator(`[data-slot="titlebar-tabs"] a[href="${href}"]`).first().click()
+        await expectSessionTitle(page, fixture.expected.targetTitle)
+      },
+    })
+    report(result)
+    expect(result.summary.blankSamples).toBe(0)
+    expect(result.summary.unknownSamples).toBe(0)
+  })
+
+  benchmark("opens the new session page before its lazy module is used", async ({ page, report }) => {
+    await setup(page, draftID)
+    const href = stressDraftHref(draftID)
+    const result = await measureFirstNavigation(page, {
+      href,
+      destinationPath: href,
+      sourceSelector: messageSelector(fixture.expected.sourceMessageIDs.at(-1)!),
+      destinationSelector: '[data-component="prompt-input"]',
+      contentSelector,
+      navigate: async () => {
+        await page.locator(`[data-slot="titlebar-tabs"] a[href="${href}"]`).first().click()
+        await expect(page.locator('[data-component="prompt-input"]')).toBeVisible()
+      },
+    })
+    report(result)
+    expect(result.summary.blankSamples).toBe(0)
+    expect(result.summary.unknownSamples).toBe(0)
+  })
+
+  benchmark("opens a child session without a blank frame", async ({ page, report }) => {
+    await setup(page)
+    const href = stressSessionHref(fixture.childID)
+    const result = await measureFirstNavigation(page, {
+      href,
+      destinationPath: href,
+      sourceSelector: messageSelector(fixture.expected.sourceMessageIDs.at(-1)!),
+      destinationSelector: messageSelector(fixture.expected.childMessageIDs.at(-1)!),
+      contentSelector,
+      navigate: async () => {
+        await page.locator(`a[href="${href}"]`, { has: page.locator('[data-component="task-tool-card"]') }).click()
+        await expectSessionTitle(page, fixture.expected.childTitle)
+      },
+    })
+    report(result)
+    expect(result.summary.blankSamples).toBe(0)
+    expect(result.summary.unknownSamples).toBe(0)
+  })
+})
+
+async function setup(page: Parameters<typeof mockStressTimeline>[0], draft?: string) {
+  await mockStressTimeline(page)
+  await installTimelineSettings(page)
+  await installStressSessionTabs(page, draft ? { draftID: draft } : undefined)
+  await page.goto(stressSessionHref(fixture.sourceID))
+  await expectSessionTitle(page, fixture.expected.sourceTitle)
+  await waitForStableTimeline(page, fixture.expected.sourceMessageIDs.at(-1)!)
+}
+
+function messageSelector(id: string) {
+  return `[data-message-id="${id}"]`
+}