[ML] Memory usage accessibility tests (elastic#198306)

## Summary

Adds accessibility tests for the ML memory usage page.

x-pack/test/accessibility/apps/group2/ml_memory_usage.ts

@@ -0,0 +1,55 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0; you may not use this file except in compliance with the Elastic License
+ * 2.0.
+ */
+
+import { FtrProviderContext } from '../../ftr_provider_context';
+
+export default function ({ getService }: FtrProviderContext) {
+  const a11y = getService('a11y');
+  const ml = getService('ml');
+
+  const jobId = 'sample_job';
+
+  describe('machine learning memory usage page Accessibility', function () {
+    before(async () => {
+      await ml.securityCommon.createMlRoles();
+      await ml.securityCommon.createMlUsers();
+      await ml.securityUI.loginAsMlPowerUser();
+
+      const jobConfig = ml.commonConfig.getADFqSingleMetricJobConfig(jobId);
+      await ml.api.createAnomalyDetectionJob(jobConfig);
+      await ml.api.openAnomalyDetectionJob(jobId);
+
+      await ml.navigation.navigateToMl();
+      await ml.navigation.navigateToMemoryUsage();
+    });
+
+    after(async () => {
+      await ml.securityCommon.cleanMlUsers();
+      await ml.securityCommon.cleanMlRoles();
+
+      await ml.api.closeAnomalyDetectionJob(jobId);
+      await ml.api.cleanMlIndices();
+    });
+
+    it('memory usage - nodes tab - page', async () => {
+      await a11y.testAppSnapshot();
+    });
+
+    it('memory usage - nodes tab - node details and node memory usage', async () => {
+      await ml.memoryUsage.expandRow();
+      await a11y.testAppSnapshot();
+
+      await ml.memoryUsage.selectNodeExpandedRowTab('mlNodesOverviewPanelMemoryTab');
+      await a11y.testAppSnapshot();
+    });
+
+    it('memory usage - memory usage tab - page', async () => {
+      await ml.memoryUsage.selectTab('memory-usage');
+      await a11y.testAppSnapshot();
+    });
+  });
+}

x-pack/test/functional/services/ml/memory_usage.ts

@@ -8,6 +8,9 @@
 import expect from '@kbn/expect';
 import { FtrProviderContext } from '../../ftr_provider_context';
 
+type NodeExpandedRowTab = 'mlNodesOverviewPanelMemoryTab' | 'mlNodesOverviewPanelDetailsTab';
+type PageTab = 'memory-usage' | 'nodes';
+
 export function MachineLearningMemoryUsageProvider({ getService }: FtrProviderContext) {
   const testSubjects = getService('testSubjects');
   const comboBox = getService('comboBox');
@@ -22,7 +25,7 @@ export function MachineLearningMemoryUsageProvider({ getService }: FtrProviderCo
       await testSubjects.existOrFail(`mlNodesOverviewPanel ${tabName}Tab`);
     },
 
-    async selectTab(tabName: string) {
+    async selectTab(tabName: PageTab) {
       await testSubjects.click(`mlMemoryUsageTab-${tabName}`);
     },
 
@@ -79,7 +82,7 @@ export function MachineLearningMemoryUsageProvider({ getService }: FtrProviderCo
       await testSubjects.setValue('mlNodesTableSearchInput', nodeId);
     },
 
-    async selectNodeExpandedRowTab(tabName: string) {
+    async selectNodeExpandedRowTab(tabName: NodeExpandedRowTab) {
       await testSubjects.click(tabName);
     },