title: Using cypress-plugin-snapshots returns .toMatchSnapshot is not a function
body: <p>I'm trying to use cypress-plugin-snapshots to take some snapshots of JavaScript objects.</p>
  
  <p>I have followed the <em>Configure Cypress.io</em> instructions on <a href="https://www.npmjs.com/package/cypress-plugin-snapshots" rel="nofollow noreferrer">https://www.npmjs.com/package/cypress-plugin-snapshots</a> but when I run my test (below) I receive the following error</p>
  
  <p><code>1) Check snapshots Should match snapshot:
       TypeError: expectedData.toMatchSnapshot is not a function
        at Context.&lt;anonymous&gt; (https://www.bbc.com/__cypress/tests?p=cypress/integration/data_driven.js-917:24:18)</code></p>
  
  <p>My test file is:</p>
  
  <pre><code>describe('Check snapshots', function () {
      it('Should match snapshot', () =&gt; {
      const expectedData = {
        fonts: 
         [ { familyName: 'Helvetica', isCustomFont: false, glyphCount: 10 },
           { familyName: 'Gurmukhi MN', isCustomFont: false, glyphCount: 33 } ]
      }
  
        expectedData.toMatchSnapshot();
      });
    });
  </code></pre>
  
  <p>I'm relatively new to both JS (and Cypress) so I am not sure exactly what it is I am doing wrong. If anyone has experience sorting this issue out I'd be really grateful for some input.</p>