Created ErrorHandler test

src/common/ErrorHandler.js

@@ -14,7 +14,6 @@ const ErrorHandler = ({ location }) => class ErrorHandler extends React.Componen
   }
 
   static getDerivedStateFromError() {
-    // Update state so the next render will show the fallback UI.
     return { hasError: true };
   }
 

test/common/ErrorHandler.test.js

@@ -0,0 +1,36 @@
+import React from 'react';
+import { shallow } from 'enzyme';
+import { Button } from 'reactstrap';
+import createErrorHandler from '../../src/common/ErrorHandler';
+
+describe('<ErrorHandler />', () => {
+  const window = {
+    location: {
+      reload: jest.fn(),
+    },
+  };
+  let wrapper;
+
+  beforeEach(() => {
+    const ErrorHandler = createErrorHandler(window);
+
+    wrapper = shallow(<ErrorHandler children={<span>Foo</span>} />);
+  });
+
+  afterEach(() => wrapper.unmount());
+
+  it('renders children when no error has occurred', () => {
+    expect(wrapper.text()).toEqual('Foo');
+    expect(wrapper.find(Button)).toHaveLength(0);
+  });
+
+  it('renders error page when error has occurred', () => {
+    wrapper.setState({ hasError: true });
+
+    expect(wrapper.text()).toContain('Oops! This is awkward :S');
+    expect(wrapper.text()).toContain(
+      'It seems that something went wrong. Try refreshing the page or just click this button.'
+    );
+    expect(wrapper.find(Button)).toHaveLength(1);
+  });
+});