Issue #2958635 by dww, mpp, mariacha1, VladimirAus: Restore link to add a...

        '#suffix' => '</p>',

      ];

    }

    $form['url_redirects']['actions'] = [

      '#theme' => 'links',

      '#links' => [],

      '#attributes' => ['class' => ['action-links']],

    ];

    $form['url_redirects']['actions']['#links']['add'] = [

      'title' => t('Add URL redirect'),

      'url' => Url::fromRoute('redirect.add', [

        'redirect' => $node->toUrl()->getInternalPath(),

        'destination' => \Drupal::destination()->get(),

      ]),

      'attributes' => [

        'class' => 'button',

        'target' => '_blank',

      ],

    ];

  }

}

<?php

namespace Drupal\Tests\redirect\Functional;

use Drupal\Tests\BrowserTestBase;

/**

 * Test the redirect functionality on node forms.

 *

 * @group redirect

 */

class RedirectNodeFormTest extends BrowserTestBase {

  /**

   * A normal logged in user.

   *

   * @var \Drupal\user\UserInterface

   */

  protected $webUser;

  /**

   * A user with permission to bypass content access checks, and add redirects.

   *

   * @var \Drupal\user\UserInterface

   */

  protected $adminUser;

  /**

   * Modules to enable.

   *

   * @var array

   */

  public static $modules = ['node', 'redirect'];

  /**

   * {@inheritdoc}

   */

  protected function setUp() {

    parent::setUp();

    // Create Basic page node type.

    if ($this->profile != 'standard') {

      $this->drupalCreateContentType([

        'type' => 'page',

        'name' => 'Basic page',

        'display_submitted' => FALSE,

      ]);

    }

    $this->webUser = $this->drupalCreateUser([

      'access content',

      'create page content',

      'edit own page content',

    ]);

    $this->adminUser = $this->drupalCreateUser([

      'access content',

      'administer redirects',

      'bypass node access',

    ]);

  }

  /**

   * Test redirect functionality on the node edit form.

   */

  public function testNodeForm() {

    // Login as a regular user.

    $this->drupalLogin($this->webUser);

    // Create "Basic page" content with title.

    $settings = [

      'title' => $this->randomMachineName(8),

    ];

    $node = $this->drupalCreateNode($settings);

    // Load the node edit form.

    $this->drupalGet('node/' . $node->id() . '/edit');

    // Make sure the redirect add button is not visible to this regular user.

    $this->assertNoRaw('Add URL redirect');

    // Now edit the same node as an admin user.

    $this->drupalLogin($this->adminUser);

    $this->drupalGet('node/' . $node->id() . '/edit');

    // Make sure the redirect add button is visible for the admin user.

    $this->assertRaw('Add URL redirect');

    // Make sure the link works as expected.

    $this->clickLink('Add URL redirect');

    $this->assertUrl('admin/config/search/redirect/add');

    $this->assertFieldsByValue($this->xpath("//input[@id = 'edit-redirect-redirect-0-uri']"), '/node/' . $node->id(), 'To: field correctly pre-filled.');

  }

}