feat: browse Subject Journals and persistent Memory links

tools/web-ux/browser-tests/memory_document_harness.ts

@@ -0,0 +1,55 @@
+import { assertEquals } from "@std/assert";
+import type { Page } from "playwright";
+
+export async function freePort(): Promise<number> {
+  const listener = Deno.listen({ hostname: "127.0.0.1", port: 0 });
+  const port = (listener.addr as Deno.NetAddr).port;
+  listener.close();
+  return port;
+}
+
+export async function waitForServer(url: string): Promise<void> {
+  for (let attempt = 0; attempt < 200; attempt += 1) {
+    try {
+      const response = await fetch(url);
+      await response.body?.cancel();
+      if (response.ok) return;
+    } catch {
+      // 所有するfixture serverの起動を有界に待つ。
+    }
+    await new Promise((resolve) => setTimeout(resolve, 50));
+  }
+  throw new Error(`fixture server did not become ready: ${url}`);
+}
+
+export async function mainScrollState(page: Page) {
+  return await page.locator("main").evaluate((main) => ({
+    scrollTop: main.scrollTop,
+    scrollHeight: main.scrollHeight,
+    clientHeight: main.clientHeight,
+  }));
+}
+
+export async function assertNoPageWideOverflow(page: Page): Promise<void> {
+  assertEquals(
+    await page.evaluate(() => {
+      const document = (globalThis as any).document;
+      return document.documentElement.scrollWidth ===
+        document.documentElement.clientWidth;
+    }),
+    true,
+  );
+}
+
+export async function assertMainOwnsVerticalScroll(page: Page): Promise<void> {
+  const nested = await page.locator("main").evaluate((main) =>
+    [...main.querySelectorAll("*")]
+      .filter((element) => {
+        const style = (globalThis as any).getComputedStyle(element);
+        return ["auto", "scroll"].includes(style.overflowY) &&
+          element.scrollHeight > element.clientHeight + 1;
+      })
+      .map((element) => `${element.tagName.toLowerCase()}.${element.className}`)
+  );
+  assertEquals(nested, []);
+}