title: Unexpected block statement surrounding arrow body with ESLint
body: <p>The following code has this warning in console:</p>
  <p><strong>Unexpected block statement surrounding arrow body; move the returned value immediately after the =`  arrow-body-style</strong></p>
  <pre><code> blobToDataURL = blob =&gt; {
      return new Promise((resolve, reject) =&gt; {
        const reader = new FileReader();
        reader.onerror = reject;
        reader.onload = e =&gt; resolve(reader.result);
        reader.readAsDataURL(blob);
      });
    };
  </code></pre>
  <p>What does it mean?</p>