[web] update notification settings copy for mentions (#35953)

GitOrigin-RevId: cc86f0931f6740f1d509118ee558719bc3559816

services/web/test/frontend/features/ide-settings/settings/project-notifications-setting.test.tsx

@@ -100,6 +100,7 @@ function renderComponent(props: { permissionsLevel?: string } = {}) {
 describe('<ProjectNotificationsSetting />', function () {
   afterEach(function () {
     fetchMock.removeRoutes().clearHistory()
+    window.metaAttributesCache.delete('ol-splitTestVariants')
   })
 
   it('shows loading indicator while preferences are loading', async function () {
@@ -168,6 +169,28 @@ describe('<ProjectNotificationsSetting />', function () {
     ).to.be.false
   })
 
+  it('shows mentions copy when comment-mentions is enabled', async function () {
+    window.metaAttributesCache.set('ol-splitTestVariants', {
+      'comment-mentions': 'enabled',
+    })
+    fetchMock.get(preferencesUrl, repliesOnlyPreferences)
+
+    renderComponent()
+
+    await waitFor(
+      () =>
+        expect(
+          screen.getByLabelText('Mentions and replies only', { exact: false })
+        ).to.exist
+    )
+    expect(
+      screen.getByText(
+        'You’ll be notified about @mentions, replies and activity on your track changes.',
+        { exact: false }
+      )
+    ).to.exist
+  })
+
   it('selects "Off" when all notifications are off', async function () {
     fetchMock.get(preferencesUrl, allNotificationsOff)