add more tests for header toolbar

__tests__/components/PageHeaderToolbar.test.jsx

@@ -1,16 +1,48 @@
 import React from 'react';
+import { MemoryRouter } from 'react-router-dom';
 import { mount } from 'enzyme';
 
 import { I18nProvider } from '@lingui/react';
 import PageHeaderToolbar from '../../src/components/PageHeaderToolbar';
 
 describe('PageHeaderToolbar', () => {
-  test('renders the expected content', () => {
-  const wrapper = mount(
-    <I18nProvider>
-      <PageHeaderToolbar />
-    </I18nProvider>
-  );
-  expect(wrapper.find('Toolbar')).toHaveLength(1);
+  const pageHelpDropdownSelector = 'Dropdown QuestionCircleIcon';
+  const pageUserDropdownSelector = 'Dropdown UserIcon';
+
+  test('expected content is rendered on initialization', () => {
+    const wrapper = mount(<I18nProvider><PageHeaderToolbar/></I18nProvider>);
+
+    expect(wrapper.find(pageHelpDropdownSelector)).toHaveLength(1);
+    expect(wrapper.find(pageUserDropdownSelector)).toHaveLength(1);
+  });
+
+  test('dropdowns have expected items and callbacks', () => {
+    const onAboutClick = jest.fn();
+    const onLogoutClick = jest.fn();
+    const wrapper = mount(
+      <MemoryRouter>
+        <I18nProvider>
+          <PageHeaderToolbar
+            onAboutClick={onAboutClick}
+            onLogoutClick={onLogoutClick}
+          />
+        </I18nProvider>
+      </MemoryRouter>
+    );
+    expect(wrapper.find('DropdownItem')).toHaveLength(0);
+    wrapper.find(pageHelpDropdownSelector).simulate('click');
+    expect(wrapper.find('DropdownItem')).toHaveLength(2);
+
+    const about = wrapper.find('DropdownItem li button');
+    about.simulate('click');
+    expect(onAboutClick).toHaveBeenCalled();
+
+    expect(wrapper.find('DropdownItem')).toHaveLength(0);
+    wrapper.find(pageUserDropdownSelector).simulate('click');
+    expect(wrapper.find('DropdownItem')).toHaveLength(2);
+
+    const logout = wrapper.find('DropdownItem li button');
+    logout.simulate('click');
+    expect(onLogoutClick).toHaveBeenCalled();
   });
 });