title: Import `spyOn` function to get rid of 'not defined' eslint error
body: <p>I have a unit test that uses <code>spyOn</code> method from <code>jest</code>.</p>
  
  <pre><code>import React from 'react';
  import expect from 'jest-matchers';
  import PointsAwardingPage from '../PointsAwardingPage';
  import PointsAwardingForm from '../children/PointsAwardingForm';
  import { shallow } from 'enzyme';
  
  it("should call change method in form", () =&gt; {
    // given
    spyOn(PointsAwardingPage.prototype, 'change').and.callThrough();
    const form = shallow(&lt;PointsAwardingPage /&gt;).find('PointsAwardingForm');
  
    // when
    form.props().onChange();
  
    // then
    expect(PointsAwardingPage.prototype.change).toHaveBeenCalled();
  });
  </code></pre>
  
  <p>Everything works well. However, I see the following <code>eslint</code> error message regarding the <code>spyOn</code> function call.</p>
  
  <p><em><code>spyOn is not defined (no-undef)</code></em>.</p>
  
  <p>Which <code>import</code> statement can I use in order to get rid of this error?</p>