title: How to use dynamic url's with testcafe fixture/tests
body: <p>Taking this fixture I would like to set the <code>checkoutId</code> based on the result from the API call in the <code>before</code> fixture hook so I can use it to set the page on my tests </p>
  
  <pre><code>let checkoutId;
  fixture`Check out as guest user`
    .page`localhost:3001/checkout/start/${checkoutId}`
    .before(async () =&gt; {
        await checkout.getCheckoutId(sampleData.cart)
        .then(id =&gt; (checkoutId = id));
  });
  
  // and here the rest of my tests based on the page
  </code></pre>
  
  <p>I tried <a href="http://devexpress.github.io/testcafe/documentation/test-api/test-code-structure.html#initialization-and-clean-up" rel="nofollow noreferrer">fixture hooks</a>, <a href="http://devexpress.github.io/testcafe/documentation/test-api/test-code-structure.html#sharing-variables-between-fixture-hooks-and-test-code" rel="nofollow noreferrer">sharing variables</a> but I can't get it to work, checkoutId is undefined when requesting the page.</p>
  
  <p>Is this scenario even possible? </p>