class UserPassRehashTest

class UserPassRehashTest extends KernelTestBase {
  use UserCreationTrait;
  
  /**
   * {@inheritdoc}
   */
  protected static $modules = [
    'user',
  ];
  
  /**
   * Tests uniqueness of hashes when no password is set.
   */
  public function testUniqueHashNoPasswordValue() : void {
    $this->installEntitySchema('user');
    $timestamp = \Drupal::time()->getRequestTime();
    $user_a = $this->createUser([], NULL, FALSE, [
      'uid' => 12,
      'mail' => '3user@example.com',
      'login' => $timestamp - 1000,
    ]);
    $user_b = $this->createUser([], NULL, FALSE, [
      'uid' => 123,
      'mail' => 'user@example.com',
      'login' => $timestamp - 1000,
    ]);
    // Unset passwords after the users are created in order to avoid
    // (different) password hashes being generated for the empty strings.
    $user_a->setPassword('');
    $user_b->setPassword('');
    $hash_a = user_pass_rehash($user_a, $timestamp);
    $hash_b = user_pass_rehash($user_b, $timestamp);
    $this->assertNotEquals($hash_a, $hash_b);
  }

}