Add feature user-admin

Change-Id: Idcdc718ee502fd803a96409e67109cdac5b8b806

tests/features/user-admin/DefaultPage.test.js

@@ -0,0 +1,19 @@
+import React from 'react';
+import { shallow } from 'enzyme';
+import { DefaultPage } from '../../../src/features/user-admin/DefaultPage';
+
+describe('user-admin/DefaultPage', () => {
+  it('renders node with correct class name', () => {
+    const props = {
+      userAdmin: {},
+      actions: {},
+    };
+    const renderedComponent = shallow(
+      <DefaultPage {...props} />
+    );
+
+    expect(
+      renderedComponent.find('.user-admin-default-page').length
+    ).toBe(1);
+  });
+});

tests/features/user-admin/redux/reducer.test.js

@@ -0,0 +1,14 @@
+import reducer from '../../../../src/features/user-admin/redux/reducer';
+
+describe('user-admin/redux/reducer', () => {
+  it('does nothing if no matched action', () => {
+    const prevState = {};
+    const state = reducer(
+      prevState,
+      { type: '__UNKNOWN_ACTION_TYPE__' }
+    );
+    expect(state).toBe(prevState);
+  });
+
+  // TODO: add global reducer test if needed.
+});