add more test for icon and aggregated view

Signed-off-by: yujin-emma <yujin.emma.work@gmail.com>

src/plugins/data_source_management/public/components/custom_database_icon/empty_icon.test.tsx

@@ -0,0 +1,15 @@
+/*
+ * Copyright OpenSearch Contributors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { shallow } from 'enzyme';
+import React from 'react';
+import { EmptyIcon } from './empty_icon';
+
+describe('Test on empty icon', () => {
+  it('should render the component normally', () => {
+    const component = shallow(<EmptyIcon />);
+    expect(component).toMatchSnapshot();
+  });
+});

src/plugins/data_source_management/public/components/custom_database_icon/error_icon.test.tsx

@@ -0,0 +1,15 @@
+/*
+ * Copyright OpenSearch Contributors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { shallow } from 'enzyme';
+import React from 'react';
+import { ErrorIcon } from './error_icon';
+
+describe('Test on empty icon', () => {
+  it('should render the component normally', () => {
+    const component = shallow(<ErrorIcon />);
+    expect(component).toMatchSnapshot();
+  });
+});