function testRegistrationEmailDuplicates() {
// Don't require e-mail verification and allow registration by site visitors
// without administrator approval.
config('user.settings')
->set('verify_mail', FALSE)
->set('register', USER_REGISTER_VISITORS)
->save();
// Set up a user to check for duplicates.
$duplicate_user = $this
->drupalCreateUser();
$edit = array();
$edit['name'] = $this
->randomName();
$edit['mail'] = $duplicate_user->mail;
// Attempt to create a new account using an existing e-mail address.
$this
->drupalPost('user/register', $edit, t('Create new account'));
$this
->assertText(t('The e-mail address @email is already registered.', array(
'@email' => $duplicate_user->mail,
)), 'Supplying an exact duplicate email address displays an error message');
// Attempt to bypass duplicate email registration validation by adding spaces.
$edit['mail'] = ' ' . $duplicate_user->mail . ' ';
$this
->drupalPost('user/register', $edit, t('Create new account'));
$this
->assertText(t('The e-mail address @email is already registered.', array(
'@email' => $duplicate_user->mail,
)), 'Supplying a duplicate email address with added whitespace displays an error message');
}