title: Testing attaching a file with Dusk - works via Tinker but not from the Test
body: <p>I have a file uploader for which I have written the following test:</p>
  
  <pre><code>$browser-&gt;visit('/product/professional-photo-prints')
          -&gt;attach('photo', __DIR__.'/storage/app/public/testing/test_upload.jpg');
  </code></pre>
  
  <p>That doesn't upload the file. No error either.</p>
  
  <p>However, when I do this:</p>
  
  <pre><code>$browser-&gt;visit('/product/professional-photo-prints')
          -&gt;tinker();
  </code></pre>
  
  <p>and once in the Terminal launched by Tinker, when I enter the exact same file uploading command I am using in the test:</p>
  
  <pre><code>$browser-&gt;attach('photo', __DIR__.'/storage/app/public/testing/test_upload.jpg');
  </code></pre>
  
  <p>...it works. I can see my Chrome instance upload the file and all.</p>
  
  <p>I can't figure out for the life of me what could be the difference between that command being run from the test itself, or from Tinker.</p>
  
  <p>Any help would be greatly appreciated. Thank you.</p>
  
  <p>P.S. I am using Laravel 5.5 and Dusk 2.0</p>