class DestinationTest

class DestinationTest extends BrowserTestBase {
  
  /**
   * {@inheritdoc}
   */
  protected static $modules = [
    'system_test',
  ];
  
  /**
   * {@inheritdoc}
   */
  protected $defaultTheme = 'stark';
  
  /**
   * Tests that $_GET/$_REQUEST['destination'] only contain internal URLs.
   */
  public function testDestination() {
    $http_client = $this->getHttpClient();
    $session = $this->getSession();
    $test_cases = [
      [
        'input' => 'node',
        'output' => 'node',
        'message' => "Standard internal example node path is present in the 'destination' parameter.",
      ],
      [
        'input' => '/example.com',
        'output' => '/example.com',
        'message' => 'Internal path with one leading slash is allowed.',
      ],
      [
        'input' => '//example.com/test',
        'output' => '',
        'message' => 'External URL without scheme is not allowed.',
      ],
      [
        'input' => 'example:test',
        'output' => 'example:test',
        'message' => 'Internal URL using a colon is allowed.',
      ],
      [
        'input' => 'http://example.com',
        'output' => '',
        'message' => 'External URL is not allowed.',
      ],
      [
        'input' => 'javascript:alert(0)',
        'output' => 'javascript:alert(0)',
        'message' => 'JavaScript URL is allowed because it is treated as an internal URL.',
      ],
    ];
    foreach ($test_cases as $test_case) {
      // Test $_GET['destination'].
      $this->drupalGet('system-test/get-destination', [
        'query' => [
          'destination' => $test_case['input'],
        ],
      ]);
      $this->assertSame($test_case['output'], $session->getPage()
        ->getContent(), $test_case['message']);
      // Test $_REQUEST['destination'].
      $post_output = $http_client->request('POST', $this->buildUrl('system-test/request-destination'), [
        'form_params' => [
          'destination' => $test_case['input'],
        ],
      ]);
      $this->assertSame($test_case['output'], (string) $post_output->getBody(), $test_case['message']);
    }
    // Make sure that 404 pages do not populate $_GET['destination'] with
    // external URLs.
    \Drupal::configFactory()->getEditable('system.site')
      ->set('page.404', '/system-test/get-destination')
      ->save();
    $this->drupalGet('http://example.com', [
      'external' => FALSE,
    ]);
    $this->assertSession()
      ->statusCodeEquals(404);
    $this->assertSame(Url::fromRoute('<front>')->toString(), $session->getPage()
      ->getContent(), 'External URL is not allowed on 404 pages.');
  }

}