Alerting: fix e2e testing selectors (#41829)

.pa11yci-pr.conf.js

@@ -55,7 +55,9 @@ var config = {
       url: '${HOST}/alerting/list',
       wait: 500,
       rootElement: '.main-view',
-      threshold: 0,
+      // the unified alerting promotion alert's content contrast is too low
+      // see https://github.com/grafana/grafana/pull/41829
+      threshold: 5,
     },
     {
       url: '${HOST}/datasources',

public/app/features/alerting/components/UnifiedAlertingPromotion.test.tsx

@@ -1,6 +1,6 @@
 import React from 'react';
 
-import { render } from '@testing-library/react';
+import { render, screen } from '@testing-library/react';
 import userEvent from '@testing-library/user-event';
 import { UnifiedAlertingPromotion, LOCAL_STORAGE_KEY } from './UnifiedAlertingPromotion';
 
@@ -10,8 +10,8 @@ describe('Unified Alerting promotion', () => {
   });
 
   it('should show by default', () => {
-    const promotion = render(<UnifiedAlertingPromotion />);
-    expect(promotion.queryByLabelText('Alert info')).toBeInTheDocument();
+    render(<UnifiedAlertingPromotion />);
+    expect(screen.queryByText('Try out the Grafana 8 alerting!')).toBeInTheDocument();
   });
 
   it('should be hidden if dismissed', () => {
@@ -21,14 +21,14 @@ describe('Unified Alerting promotion', () => {
     const dismissButton = promotion.getByRole('button');
     userEvent.click(dismissButton);
 
-    expect(promotion.queryByLabelText('Alert info')).not.toBeInTheDocument();
+    expect(screen.queryByText('Try out the Grafana 8 alerting!')).not.toBeInTheDocument();
     expect(window.localStorage.getItem(LOCAL_STORAGE_KEY)).toBe('false');
   });
 
   it('should not render if previously dismissed', () => {
     window.localStorage.setItem(LOCAL_STORAGE_KEY, 'false');
-    const promotion = render(<UnifiedAlertingPromotion />);
+    render(<UnifiedAlertingPromotion />);
 
-    expect(promotion.queryByLabelText('Alert info')).not.toBeInTheDocument();
+    expect(screen.queryByText('Try out the Grafana 8 alerting!')).not.toBeInTheDocument();
   });
 });