fix(app): stabilize session timeline layout continuity (#34533)

2026-07-02 12:36:47 +10:00
parent f266e829cf
commit 3cf71808c4
57 changed files with 6159 additions and 142 deletions
@@ -0,0 +1,192 @@
+import { expect, test } from "@playwright/test"
+import {
+  defineVisualRegions,
+  reportVisualStability,
+  startVisualProbe,
+  stopVisualProbe,
+  visualPlan,
+} from "../../utils/visual-stability"
+import {
+  assistantID,
+  assistantMessage,
+  event,
+  partUpdated,
+  setupTimeline,
+  textPart,
+  toolPart,
+  userMessage,
+  waitForVisualSettle,
+} from "./fixture"
+
+const inputs = {
+  read: { filePath: "src/a.ts", offset: 0, limit: 120 },
+  glob: { path: ".", pattern: "**/*.ts" },
+  grep: { path: ".", pattern: "stable", include: "*.ts" },
+  list: { path: "src" },
+}
+
+test("appends context operations while the group is expanded", async ({ page }, testInfo) => {
+  const firstID = "prt_append_01_read"
+  const followingID = "prt_append_99_following"
+  const timeline = await setupTimeline(page, {
+    messages: [
+      userMessage(),
+      assistantMessage([toolPart(firstID, "read", "running", inputs.read), textPart(followingID, "Following append")], {
+        completed: false,
+      }),
+    ],
+    cpuRate: 4,
+  })
+  const initialGroup = `[data-timeline-part-ids="${firstID}"]`
+  await page.locator(`${initialGroup} [data-slot="collapsible-trigger"]`).click()
+  await waitForVisualSettle(page, [initialGroup, `[data-timeline-part-id="${followingID}"]`])
+  const regions = defineVisualRegions({
+    context: {
+      selector: '[data-timeline-part-ids^="prt_append_01_read"]',
+      closest: '[data-timeline-row="AssistantPart"]',
+    },
+    following: { selector: `[data-timeline-part-id="${followingID}"]`, closest: '[data-timeline-row="AssistantPart"]' },
+  })
+  await startVisualProbe(page, regions)
+  await timeline.send(partUpdated(toolPart("prt_append_02_glob", "glob", "running", inputs.glob)), 180)
+  await timeline.send(partUpdated(toolPart("prt_append_03_grep", "grep", "completed", inputs.grep)), 240)
+  await timeline.send(partUpdated(toolPart("prt_append_04_list", "list", "completed", inputs.list)), 500)
+  const trace = await stopVisualProbe<keyof typeof regions>(page)
+  await reportVisualStability(
+    testInfo,
+    "context-append",
+    trace,
+    visualPlan(
+      regions,
+      [
+        { type: "required", regions: ["context", "following"] },
+        { type: "unique", regions: ["context", "following"] },
+        { type: "stable", regions: ["context", "following"] },
+        { type: "opacity", regions: "all" },
+        { type: "continuity", regions: "all" },
+        { type: "motion", regions: ["following"], maxPositionReversals: 0 },
+        { type: "label-stability", regions: "all" },
+        { type: "preserve-bottom-anchor" },
+        { type: "flow", regions: ["context", "following"] },
+      ],
+      { perMarker: true },
+    ),
+  )
+  await expect(
+    page.locator(
+      '[data-timeline-part-ids="prt_append_01_read,prt_append_02_glob,prt_append_03_grep,prt_append_04_list"]',
+    ),
+  ).toBeVisible()
+  await expect(
+    page.locator('[data-timeline-part-ids^="prt_append_01_read"] [data-slot="collapsible-trigger"]'),
+  ).toHaveAttribute("aria-expanded", "true")
+})
+
+test("splits and merges context groups when a middle text part changes", async ({ page }, testInfo) => {
+  const textID = "prt_split_02_text"
+  const followingID = "prt_split_99_following"
+  const timeline = await setupTimeline(page, {
+    messages: [
+      userMessage(),
+      assistantMessage([
+        toolPart("prt_split_01_read", "read", "completed", inputs.read),
+        textPart(textID, "Boundary"),
+        toolPart("prt_split_03_glob", "glob", "completed", inputs.glob),
+        textPart(followingID, "Following split groups"),
+      ]),
+    ],
+    cpuRate: 4,
+  })
+  const regions = defineVisualRegions({
+    following: { selector: `[data-timeline-part-id="${followingID}"]`, closest: '[data-timeline-row="AssistantPart"]' },
+  })
+  await startVisualProbe(page, regions)
+  await timeline.send(
+    event("message.part.removed", { sessionID: "ses_timeline_stability", messageID: assistantID, partID: textID }),
+    500,
+  )
+  await expect(page.locator('[data-timeline-part-ids="prt_split_01_read,prt_split_03_glob"]')).toBeVisible()
+  await timeline.send(partUpdated(textPart(textID, "Boundary restored")), 500)
+  await expect(page.locator('[data-timeline-part-ids="prt_split_01_read"]')).toBeVisible()
+  await expect(page.locator('[data-timeline-part-ids="prt_split_03_glob"]')).toBeVisible()
+  const trace = await stopVisualProbe<keyof typeof regions>(page)
+  await reportVisualStability(
+    testInfo,
+    "context-split-merge",
+    trace,
+    visualPlan(
+      regions,
+      [
+        { type: "required", regions: ["following"] },
+        { type: "unique", regions: ["following"] },
+        { type: "stable", regions: ["following"] },
+        { type: "opacity", regions: "all" },
+        { type: "continuity", regions: "all" },
+        { type: "motion", regions: "all", maxPositionReversals: 1 },
+        { type: "label-stability", regions: "all" },
+      ],
+      { perMarker: true },
+    ),
+  )
+})
+
+test("removing the first context member replaces the group once without overlapping following content", async ({
+  page,
+}, testInfo) => {
+  const ids = ["prt_key_01_read", "prt_key_02_glob", "prt_key_03_grep"]
+  const followingID = "prt_key_99_following"
+  const timeline = await setupTimeline(page, {
+    messages: [
+      userMessage(),
+      assistantMessage([
+        toolPart(ids[0]!, "read", "completed", inputs.read),
+        toolPart(ids[1]!, "glob", "completed", inputs.glob),
+        toolPart(ids[2]!, "grep", "completed", inputs.grep),
+        textPart(followingID, "Following replaced group"),
+      ]),
+    ],
+    cpuRate: 4,
+  })
+  const original = page.locator(`[data-timeline-part-ids="${ids.join(",")}"]`)
+  const originalRowKey = await original.evaluate((element) =>
+    element.closest("[data-timeline-key]")?.getAttribute("data-timeline-key"),
+  )
+  await original.locator('[data-slot="collapsible-trigger"]').click()
+  await expect(original.locator('[data-slot="collapsible-trigger"]')).toHaveAttribute("aria-expanded", "true")
+  const regions = defineVisualRegions({
+    context: {
+      selector: '[data-timeline-part-ids*="prt_key_02_glob"]',
+      closest: '[data-timeline-row="AssistantPart"]',
+    },
+    following: { selector: `[data-timeline-part-id="${followingID}"]`, closest: '[data-timeline-row="AssistantPart"]' },
+  })
+  await startVisualProbe(page, regions)
+  await timeline.send(
+    event("message.part.removed", { sessionID: "ses_timeline_stability", messageID: assistantID, partID: ids[0] }),
+    500,
+  )
+  const trace = await stopVisualProbe<keyof typeof regions>(page)
+  await reportVisualStability(
+    testInfo,
+    "context-first-remove",
+    trace,
+    visualPlan(regions, [
+      { type: "required", regions: ["context", "following"] },
+      { type: "unique", regions: ["context", "following"] },
+      { type: "opacity", regions: "all" },
+      { type: "continuity", regions: "all" },
+      { type: "motion", regions: "all", maxPositionReversals: 0 },
+      { type: "label-stability", regions: "all" },
+      { type: "flow", regions: ["context", "following"] },
+    ]),
+  )
+  await expect(page.locator(`[data-timeline-part-ids="${ids.slice(1).join(",")}"]`)).toBeVisible()
+  expect(
+    await page
+      .locator(`[data-timeline-part-ids="${ids.slice(1).join(",")}"]`)
+      .evaluate((element) => element.closest("[data-timeline-key]")?.getAttribute("data-timeline-key")),
+  ).toBe(originalRowKey)
+  await expect(
+    page.locator(`[data-timeline-part-ids="${ids.slice(1).join(",")}"] [data-slot="collapsible-trigger"]`),
+  ).toHaveAttribute("aria-expanded", "true")
+})