Created NotFound component

test/App.test.js

@@ -19,12 +19,17 @@ describe('<App />', () => {
 
   it('renders app main routes', () => {
     const routes = wrapper.find(Route);
-    const expectedRoutesCount = 3;
-    const second = 2;
+    const expectedRoutesCount = 4;
+    const expectedPaths = [
+      '/server/create',
+      '/',
+      '/server/:serverId',
+    ];
 
+    expect.assertions(expectedPaths.length + 1);
     expect(routes).toHaveLength(expectedRoutesCount);
-    expect(routes.at(0).prop('path')).toEqual('/server/create');
-    expect(routes.at(1).prop('path')).toEqual('/');
-    expect(routes.at(second).prop('path')).toEqual('/server/:serverId');
+    expectedPaths.forEach((path, index) => {
+      expect(routes.at(index).prop('path')).toEqual(path);
+    });
   });
 });

test/common/NotFound.test.js

@@ -0,0 +1,30 @@
+import React from 'react';
+import { shallow } from 'enzyme';
+import { Link } from 'react-router-dom';
+import NotFound from '../../src/common/NotFound';
+
+describe('<NotFound />', () => {
+  let wrapper;
+  let content;
+
+  beforeEach(() => {
+    wrapper = shallow(<NotFound />);
+    content = wrapper.text();
+  });
+
+  afterEach(() => wrapper.unmount());
+
+  it('shows expected error title', () => expect(content).toContain('Oops! We could not find requested route.'));
+
+  it('shows expected error message', () =>
+    expect(content).toContain(
+      'Use your browser\'s back button to navigate to the page you have previously come from, or just press this button.'
+    ));
+
+  it('shows a link to the home', () => {
+    const link = wrapper.find(Link);
+
+    expect(link.prop('to')).toEqual('/');
+    expect(link.prop('className')).toEqual('btn btn-outline-primary btn-lg');
+  });
+});