Fix E2E test

e2e/helpers/playwright.ts

@@ -29,6 +29,7 @@ interface RouterProbe {
 declare global {
 	interface Window {
 		__routerProbe?: RouterProbe;
+		__scrollYAtPress?: number;
 	}
 }
 
@@ -503,6 +504,34 @@ export async function waitForDropToSettle(page: Page) {
 	await page.waitForTimeout(2 * DND_KIT_CLICK_SUPPRESSION_MS);
 }
 
+/**
+ * The scroll position the page was at when it was last pressed, for asserting that
+ * an action did not move the viewer. Playwright scrolls a click target into view
+ * itself, and a retried click force-scrolls it again, so a reading taken before the
+ * press can be stale by the time the press lands.
+ */
+export async function trackScrollYAtPress(page: Page) {
+	await page.evaluate(() => {
+		window.__scrollYAtPress = undefined;
+		document.addEventListener(
+			"pointerdown",
+			() => {
+				window.__scrollYAtPress = window.scrollY;
+			},
+			{ capture: true },
+		);
+	});
+
+	return async () => {
+		const scrollY = await page.evaluate(() => window.__scrollYAtPress);
+		if (typeof scrollY !== "number") {
+			throw new Error("The page was never pressed");
+		}
+
+		return scrollY;
+	};
+}
+
 /** Asserts the page rendered rather than the error boundary catching something. */
 export async function expectNoErrorPage(page: Page) {
 	await expect(page.getByTestId("error-page")).toHaveCount(0);

e2e/sendouq.spec.ts

@@ -19,6 +19,7 @@ import {
 	isNotVisible,
 	runRoutine,
 	test,
+	trackScrollYAtPress,
 } from "./helpers/playwright";
 import { NotificationPopover } from "./pages/layout/notification-popover";
 import { SendouQLookingPage } from "./pages/sendouq/sendouq-looking-page";
@@ -237,13 +238,15 @@ test.describe("SendouQ", () => {
 
 			const lastCard = looking.groupCard(otherUsers.length - 1);
 			await lastCard.root.scrollIntoViewIfNeeded();
-			const scrollBefore = await page.evaluate(() => window.scrollY);
-			expect(scrollBefore).toBeGreaterThan(0);
+			expect(await page.evaluate(() => window.scrollY)).toBeGreaterThan(0);
 
+			const scrollYAtPress = await trackScrollYAtPress(page);
 			await lastCard.pressSuggest();
 
 			await expect(looking.groupCard(0).trail).toBeVisible();
-			expect(await page.evaluate(() => window.scrollY)).toBe(scrollBefore);
+			expect(await page.evaluate(() => window.scrollY)).toBe(
+				await scrollYAtPress(),
+			);
 		});
 	});