feat: import Chinese-localized Buzz source snapshot

Signed-off-by: cls_宁波本机 <908705107@qq.com>

desktop/tests/e2e/markdown-parse-cache.spec.ts

@@ -0,0 +1,73 @@
+import { expect, test } from "@playwright/test";
+
+import { installMockBridge } from "../helpers/bridge";
+
+/**
+ * Regression gate for the markdown parse cache (shared/ui/markdown/nodeCache).
+ *
+ * The timeline's per-channel-switch remount used to re-run every row's
+ * react-markdown parse; the cache makes warm re-entries pure element reuse.
+ * This spec asserts the deterministic invariant behind that win: a warm
+ * channel switch performs ZERO fresh parses. Unlike the wall-clock
+ * benchmark (warm-switch-markdown.perf.ts, instrument-only), this is
+ * machine-independent and safe to gate CI on — if someone disconnects
+ * MarkdownInner from the cache or breaks the key, this fails.
+ */
+
+async function parseCount(page: import("@playwright/test").Page) {
+  return page.evaluate(() => window.__BUZZ_E2E_MD_PARSE_COUNT__?.() ?? -1);
+}
+
+async function settleChannel(
+  page: import("@playwright/test").Page,
+  title: string,
+) {
+  await expect(page.getByTestId("chat-title")).toHaveText(title);
+  await expect(page.locator('[data-render-pending="true"]')).toHaveCount(0);
+  await expect(
+    page.getByTestId("message-timeline").locator("[data-message-id]").first(),
+  ).toBeVisible();
+  // Let any trailing deferred commits flush before reading the counter.
+  await page.waitForTimeout(300);
+}
+
+test("warm channel switches trigger zero fresh markdown parses", async ({
+  page,
+}) => {
+  await installMockBridge(page);
+  await page.goto("/");
+  await page.waitForFunction(
+    () => typeof window.__BUZZ_E2E_MD_PARSE_COUNT__ === "function",
+  );
+
+  // Cold visits populate the query caches and the markdown node cache.
+  await page.getByTestId("channel-deep-history").click();
+  await settleChannel(page, "deep-history");
+  await page.getByTestId("channel-general").click();
+  await settleChannel(page, "general");
+
+  const afterCold = await parseCount(page);
+  // Sanity: the cold visits really parsed rows (counter is wired up).
+  expect(afterCold).toBeGreaterThan(10);
+
+  // Warm switches: every row must be a cache hit.
+  let previous = afterCold;
+  for (let round = 0; round < 2; round += 1) {
+    await page.getByTestId("channel-deep-history").click();
+    await settleChannel(page, "deep-history");
+    const inDeepHistory = await parseCount(page);
+    expect(
+      inDeepHistory - previous,
+      `warm switch into deep-history (round ${round}) re-parsed markdown`,
+    ).toBe(0);
+
+    await page.getByTestId("channel-general").click();
+    await settleChannel(page, "general");
+    const inGeneral = await parseCount(page);
+    expect(
+      inGeneral - inDeepHistory,
+      `warm switch into general (round ${round}) re-parsed markdown`,
+    ).toBe(0);
+    previous = inGeneral;
+  }
+});