github-profile-readme-generator/src/components/__tests__/header.test.js

import React from 'react';
import { shallow } from 'enzyme';
import toJson from 'enzyme-to-json';

import Header from '../header';

describe('Header', () => {
  const component = shallow(<Header heading="heading" />);

  it('renders correctly', () => {
    expect(toJson(component)).toMatchSnapshot();
  });
});