title: How to get yup.string() to require string of any length (including 0)
body: <p>I'm wondering if someone could advise me on how to get yup to validate strings of any length (including length 0).</p>
  <p>Just using</p>
  <pre><code>yup.string().required().validateSync(&quot;&quot;)
  </code></pre>
  <p>will throw an error on an empty string...</p>
  <p>In the past this was the recommended way to do it:</p>
  <pre><code>string().required().min(0) 
  </code></pre>
  <p>but that way no longer works.. (<a href="https://github.com/jquense/yup/issues/136#issuecomment-339235070" rel="nofollow noreferrer">https://github.com/jquense/yup/issues/136#issuecomment-339235070</a>)</p>
  <p>Can someone advise me on how to get yup to require that a string is sent, but to not error on length 0 strings?</p>
  <p>Thanks!</p>