Issue #3259603 by beagaliana: Add a fuctional test that checks the form is saved as expected

<?php

namespace Drupal\Tests\whatsapp\Functional;

namespace Drupal\onlyone\Utility;

use Drupal\Tests\BrowserTestBase;

/**

 * WhatsApp functional test.

 *

 * @group whatsapp

 */

class WhatsappFormTest extends BrowserTestBase

{

  /**

   * {@inheritdoc}

   */

  protected static $modules = ['whatsapp', 'whatsapp_test', 'key', 'user'];

  /**

   * {@inheritdoc}

   */

  protected $defaultTheme = 'stable';

  /**

   * {@inheritdoc}

   */

  protected function setUp(): void {

    parent::setUp();

    $this->adminUser = $this->drupalCreateUser(['whatsapp configuration form',

      'administer keys',

    ]);

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

  }

  /**

   * Tests the config form.

   */

  public function testSettingsForm() {

    // Add a key with a 4 characters.

    $this->drupalGet('admin/config/system/keys/add');

    $testingKey = [

      'id' => 'testing_key',

      'label' => 'Testing Key',

      'key_type' => 'authentication',

      'key_input_settings[key_value]' => str_pad('', 4, 'z'),

    ];

    $this->submitForm($testingKey, 'Save');

    $assert_session = $this->assertSession();

    $edit = [

      'id' => 'testing_key',

    ];

    $this->drupalGet('admin/config/services/whatsapp');

    $this->submitForm($edit, 'Save configuration');

    $assert_session->statusCodeEquals(200);

    $assert_session->pageTextNotContains('No keys are available.');

  }

}