test(core): migrate end-to-end test to PlayWright

Signed-off-by: Ferdinand Thiessen <opensource@fthiessen.de>

Author: susnux

.github/workflows/cypress.yml

@@ -141,10 +141,10 @@ jobs:
       matrix:
         # Run multiple copies of the current job in parallel
         # Please increase the number or runners as your tests suite grows (0 based index for e2e tests)
-        containers: ['setup', '0', '1', '2', '3', '4', '5', '6']
+        containers: ['setup', '0', '1', '2', '3', '4', '5']
         # Hack as strategy.job-total includes the "setup" and GitHub does not allow math expressions
         # Always align this number with the total of e2e runners (max. index + 1)
-        total-containers: [7]
+        total-containers: [6]
 
     services:
       mysql:

.github/workflows/playwright.yml

@@ -82,8 +82,8 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        shardIndex: [1, 2, 3]
-        shardTotal: [3]
+        shardIndex: [1, 2, 3, 4]
+        shardTotal: [4]
     outputs:
       node-version: ${{ steps.versions.outputs.node-version }}
       package-manager-version: ${{ steps.versions.outputs.package-manager-version }}

cypress/e2e/core/404-error.cy.ts

@@ -0,0 +1,21 @@
+/*
+ * SPDX-FileCopyrightText: 2026 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+import { test, expect } from '@playwright/test'
+
+test.describe('404 error page', () => {
+	test('renders 404 page with a link back to login', async ({ page }) => {
+		// No authentication — the 404 page is shown to unauthenticated visitors.
+		await page.goto('/doesnotexist')
+
+		await expect(page.getByRole('heading', { name: /Page not found/ })).toBeVisible()
+
+		const backLink = page.getByRole('link', { name: /Back to Nextcloud/ })
+		await expect(backLink).toBeVisible()
+		await backLink.click()
+
+		await expect(page).toHaveURL(/\/login$/)
+	})
+})