Just an idea / me going all #microperf here

JasonStoltz · JasonStoltz · commit 49570d441b8d · 2020-10-07T14:41:14.000-04:00
#79749 (comment)
diff --git a/x-pack/plugins/enterprise_search/public/applications/__mocks__/shallow_usememo.mock.ts b/x-pack/plugins/enterprise_search/public/applications/__mocks__/shallow_usememo.mock.ts
@@ -0,0 +1,21 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License;
+ * you may not use this file except in compliance with the Elastic License.
+ */
+
+jest.mock('react', () => ({
+  ...(jest.requireActual('react') as object),
+  useMemo: jest.fn((fn) => fn()), // Calls on mount/every update - use mount for more complex behavior
+}));
+
+/**
+ * Example usage within a component test using shallow():
+ *
+ * import '../../../__mocks__/shallow_usememo.mock'; // Must come before React's import, adjust relative path as needed
+ *
+ * import React from 'react';
+ * import { shallow } from 'enzyme';
+ *
+ * // ... etc.
+ */
diff --git a/x-pack/plugins/enterprise_search/public/applications/app_search/components/credentials/credentials_list/credentials_list.tsx b/x-pack/plugins/enterprise_search/public/applications/app_search/components/credentials/credentials_list/credentials_list.tsx
@@ -4,7 +4,7 @@
  * you may not use this file except in compliance with the Elastic License.
  */
 
-import React from 'react';
+import React, { useMemo } from 'react';
 import { EuiBasicTable, EuiBasicTableColumn, EuiButtonIcon, EuiCopy } from '@elastic/eui';
 import { CriteriaWithPagination } from '@elastic/eui/src/components/basic_table/basic_table';
 import { useActions, useValues } from 'kea';
@@ -22,7 +22,7 @@ export const CredentialsList: React.FC = () => {
 
   const { apiTokens, meta } = useValues(CredentialsLogic);
 
-  const items = apiTokens.slice().sort(apiTokenSort);
+  const items = useMemo(() => apiTokens.slice().sort(apiTokenSort), [apiTokens]);
 
   const columns: Array<EuiBasicTableColumn<IApiToken>> = [
     {
