snapshot of https://github.com/RocketChat/Rocket.Chat.git (develop, 2026-09-16; blobs > 131072B omitted)

apps/meteor/tests/e2e/messaging-scroll-to-bottom.spec.ts

@@ -0,0 +1,119 @@
+import { faker } from '@faker-js/faker';
+import type { Locator } from 'playwright-core';
+
+import { Users } from './fixtures/userStates';
+import { HomeChannel } from './page-objects';
+import { deleteChannel } from './utils';
+import type { BaseTest } from './utils/test';
+import { expect, test } from './utils/test';
+
+test.use({ storageState: Users.admin.state });
+test.describe.serial('Messaging scroll to bottom', () => {
+	let targetChannel: { name: string; _id: string };
+	let poHomeChannel: HomeChannel;
+	let mainMessage: { _id: string };
+
+	const fillMessages = async (api: BaseTest['api']) => {
+		const firstResponse = await api.post('/chat.postMessage', {
+			roomId: targetChannel._id,
+			text: faker.lorem.paragraphs(6),
+		});
+
+		const { message: firstMessage } = await firstResponse.json();
+		mainMessage = firstMessage;
+
+		await Promise.all(
+			Array.from({ length: 4 }).map(() =>
+				api.post('/chat.postMessage', {
+					roomId: targetChannel._id,
+					text: faker.lorem.paragraphs(6),
+				}),
+			),
+		);
+
+		await Promise.all(
+			Array.from({ length: 5 }).map(() =>
+				api.post('/chat.postMessage', {
+					roomId: targetChannel._id,
+					text: faker.lorem.paragraphs(6),
+					tmid: firstMessage._id,
+				}),
+			),
+		);
+	};
+
+	const scrollToTop = async (scroller: Locator) => {
+		await scroller.evaluate((el) => {
+			el.scrollTop = 0;
+		});
+		await expect(scroller).toHaveJSProperty('scrollTop', 0);
+	};
+
+	const expectScrolledToBottom = async (scroller: Locator) => {
+		await expect.poll(() => scroller.evaluate((el) => Math.abs(el.scrollTop - (el.scrollHeight - el.clientHeight)) < 2)).toBe(true);
+	};
+
+	test.beforeAll(async ({ api }) => {
+		await api
+			.post('/channels.create', { name: faker.string.uuid() })
+			.then((res) => res.json())
+			.then((data) => {
+				targetChannel = data.channel;
+			});
+
+		await fillMessages(api);
+	});
+
+	test.beforeEach(async ({ page }) => {
+		poHomeChannel = new HomeChannel(page);
+		await poHomeChannel.gotoChannelThread(targetChannel._id, mainMessage._id);
+	});
+
+	test.afterAll(async ({ api }) => {
+		await deleteChannel(api, targetChannel.name);
+	});
+
+	test('should scroll the main message list to bottom when sending a message in the main channel', async ({ page }) => {
+		await page.setViewportSize({ width: 1023, height: 700 });
+
+		await scrollToTop(poHomeChannel.content.mainMessageListScroller);
+
+		await poHomeChannel.content.sendMessage('main channel message');
+
+		await expectScrolledToBottom(poHomeChannel.content.mainMessageListScroller);
+	});
+
+	test('should scroll the thread message list to bottom when sending a message in the thread', async ({ page }) => {
+		await page.setViewportSize({ width: 1023, height: 700 });
+
+		await scrollToTop(poHomeChannel.content.threadMessageListScroller);
+
+		await poHomeChannel.content.sendMessageInThread('new thread reply');
+
+		await expectScrolledToBottom(poHomeChannel.content.threadMessageListScroller);
+	});
+
+	test('should not scroll the main channel message list when sending a message in the thread', async ({ page }) => {
+		await page.setViewportSize({ width: 1023, height: 700 });
+
+		await scrollToTop(poHomeChannel.content.mainMessageListScroller);
+		await scrollToTop(poHomeChannel.content.threadMessageListScroller);
+
+		await poHomeChannel.content.sendMessageInThread('another thread reply');
+
+		await expectScrolledToBottom(poHomeChannel.content.threadMessageListScroller);
+		await expect(poHomeChannel.content.mainMessageListScroller).toHaveJSProperty('scrollTop', 0);
+	});
+
+	test('should not scroll the thread message list when sending a message in the main channel', async ({ page }) => {
+		await page.setViewportSize({ width: 1023, height: 700 });
+
+		await scrollToTop(poHomeChannel.content.mainMessageListScroller);
+		await scrollToTop(poHomeChannel.content.threadMessageListScroller);
+
+		await poHomeChannel.content.sendMessage('another main channel message');
+
+		await expectScrolledToBottom(poHomeChannel.content.mainMessageListScroller);
+		await expect(poHomeChannel.content.threadMessageListScroller).toHaveJSProperty('scrollTop', 0);
+	});
+});