E2E/Playwright: MM-T5424 Find channel limit to 50 results (#23248)

* fix aria-label of Find Channels modal

* add components

* add test for MM-T5424

---------

Co-authored-by: Mattermost Build <build@mattermost.com>

e2e-tests/playwright/tests/functional/channels/search/find_channels.spec.ts

@@ -0,0 +1,61 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+import {expect, test} from '@e2e-support/test_fixture';
+import {createRandomChannel} from '@e2e-support/server';
+
+test('MM-T5424 Find channel search returns only 50 results when there are more than 50 channels with similar names', async ({
+    pw,
+    pages,
+}) => {
+    const {adminClient, user, team} = await pw.initSetup();
+
+    const commonName = 'test_channel';
+
+    // # Create more than 50 channels with similar names
+    const channelsRes = [];
+    for (let i = 0; i < 100; i++) {
+        let suffix = i.toString();
+        if (i < 10) {
+            suffix = `0${i}`;
+        }
+        const channel = createRandomChannel({
+            teamId: team.id,
+            name: `${commonName}_${suffix}`,
+            displayName: `Test Channel ${suffix}`,
+        });
+        channelsRes.push(adminClient.createChannel(channel));
+    }
+    await Promise.all(channelsRes);
+
+    // # Log in a user in new browser context
+    const {page} = await pw.testBrowser.login(user);
+
+    // # Visit a default channel page
+    const channelsPage = new pages.ChannelsPage(page);
+    await channelsPage.goto();
+    await channelsPage.toBeVisible();
+
+    // # Click on "Find channel" and type "test_channel"
+    if (pw.isSmallScreen()) {
+        await channelsPage.headerMobile.toggleSidebar();
+    }
+    await channelsPage.sidebarLeft.findChannelButton.click();
+
+    await channelsPage.findChannelsModal.toBeVisible();
+    await channelsPage.findChannelsModal.input.fill(commonName);
+
+    const limitCount = 50;
+
+    // # Only 50 results for similar name should be displayed.
+    await expect(channelsPage.findChannelsModal.searchList).toHaveCount(limitCount);
+
+    for (let i = 0; i < limitCount; i++) {
+        let suffix = i.toString();
+        if (i < 10) {
+            suffix = `0${i}`;
+        }
+
+        await expect(channelsPage.findChannelsModal.container.getByTestId(`${commonName}_${suffix}`)).toBeVisible();
+    }
+});