add unit test for persisting that banner has been dismissed

x-pack/plugins/security_solution/public/management/pages/policy/view/policy_settings_form/policy_settings_form.test.tsx

@@ -23,6 +23,7 @@ import type { PolicyConfig } from '../../../../../../common/endpoint/types';
 import { AntivirusRegistrationModes } from '../../../../../../common/endpoint/types';
 import userEvent from '@testing-library/user-event';
 import { cloneDeep } from 'lodash';
+import type { IStorageWrapper } from '@kbn/kibana-utils-plugin/public';
 
 jest.mock('../../../../../common/hooks/use_license');
 
@@ -33,11 +34,13 @@ describe('Endpoint Policy Settings Form', () => {
   let render: () => ReturnType<AppContextTestRender['render']>;
   let renderResult: ReturnType<typeof render>;
   let upsellingService: UpsellingService;
+  let storageMock: IStorageWrapper;
 
   beforeEach(() => {
     const mockedContext = createAppRootMockRenderer();
 
     upsellingService = mockedContext.startServices.upselling;
+    storageMock = mockedContext.startServices.storage;
 
     formProps = {
       policy: new FleetPackagePolicyGenerator('seed').generateEndpointPackagePolicy().inputs[0]
@@ -50,15 +53,43 @@ describe('Endpoint Policy Settings Form', () => {
     render = () => (renderResult = mockedContext.render(<PolicySettingsForm {...formProps} />));
   });
 
-  it('should show the event merging banner for 8.16', () => {
-    render();
-    expect(renderResult.getByTestId('eventMergingCallout')).toBeTruthy();
-  });
+  describe('event merging banner', () => {
+    it('should show the event merging banner for 8.16 if it has never been dismissed', () => {
+      render();
 
-  it('should not show the event merging banner after it has been dismissed', () => {
-    render();
-    renderResult.getByTestId('euiDismissCalloutButton').click();
-    expect(renderResult.queryByTestId('eventMergingCallout')).toBeNull();
+      expect(renderResult.getByTestId('eventMergingCallout')).toBeInTheDocument();
+    });
+
+    it('should show the event merging banner for 8.16 if `securitySolution.showEventMergingBanner` is `true`', () => {
+      storageMock.set('securitySolution.showEventMergingBanner', true);
+      render();
+
+      expect(renderResult.getByTestId('eventMergingCallout')).toBeInTheDocument();
+    });
+
+    it('should hide the event merging banner when user dismisses it', () => {
+      render();
+      expect(renderResult.getByTestId('eventMergingCallout')).toBeInTheDocument();
+
+      renderResult.getByTestId('euiDismissCalloutButton').click();
+
+      expect(renderResult.queryByTestId('eventMergingCallout')).not.toBeInTheDocument();
+    });
+
+    it('should persist that event merging banner have been dismissed', () => {
+      render();
+
+      renderResult.getByTestId('euiDismissCalloutButton').click();
+
+      expect(storageMock.get('securitySolution.showEventMergingBanner')).toBe(false);
+    });
+
+    it('should not show the banner if it was dismissed before', () => {
+      storageMock.set('securitySolution.showEventMergingBanner', false);
+      render();
+
+      expect(renderResult.queryByTestId('eventMergingCallout')).not.toBeInTheDocument();
+    });
   });
 
   it.each([
@@ -102,7 +133,7 @@ describe('Endpoint Policy Settings Form', () => {
     ])('should include %s card', (_, testSubjSelector) => {
       render();
 
-      expect(renderResult.queryByTestId(testSubjSelector)).toBeNull();
+      expect(renderResult.queryByTestId(testSubjSelector)).not.toBeInTheDocument();
     });
 
     it('should display upselling component', () => {