Drupal Simpletest for Image Upload The following code is working fine for uploading images. The node is being created but the uploaded images (under /sites/default/files/simpletest) are getting deleted after each complete test suite run.
Here the sample code
public function testArticleCreate() {
  $edit = array();
  $edit['title'] = $this-&gt;randomName(8);
  $edit[&quot;field_description[und][0][value]&quot;] = $this-&gt;randomName(16);
  $field_name = 'field_image';
  $edit['files[' . $field_name . '_' . LANGUAGE_NONE . '_0]'] = 'sites/default/files/test-image.png'; // existed
  $this-&gt;drupalPost('node/add/article', $edit, t('Save'));
  $this-&gt;drupalGet(&quot;node/1/edit&quot;);
  }

Screenshot

Getting 404 not found for the image path (sites/default/files/simpletest/505284/test-image.png)
Any suggestions?
I came to know that it's by design but not a bug. We can do nothing with the uploaded images. The SimpleTest files will be deleted automatically after successful test suite run.