<?php

class AJAXTestCase extends DrupalWebTestCase {
  function setUp() {
    $modules = func_get_args();
    if (isset($modules[0]) && is_array($modules[0])) {
      $modules = $modules[0];
    }
    parent::setUp(array_unique(array_merge(array('ajax_test', 'ajax_forms_test'), $modules)));
  }

  /**
   * Assert that a command with the required properties exists within the array of Ajax commands returned by the server.
   *
   * The Ajax framework, via the ajax_deliver() and ajax_render() functions,
   * returns an array of commands. This array sometimes includes commands
   * automatically provided by the framework in addition to commands returned by
   * a particular page callback. During testing, we're usually interested that a
   * particular command is present, and don't care whether other commands
   * precede or follow the one we're interested in. Additionally, the command
   * we're interested in may include additional data that we're not interested
   * in. Therefore, this function simply asserts that one of the commands in
   * $haystack contains all of the keys and values in $needle. Furthermore, if
   * $needle contains a 'settings' key with an array value, we simply assert
   * that all keys and values within that array are present in the command we're
   * checking, and do not consider it a failure if the actual command contains
   * additional settings that aren't part of $needle.
   *
   * @param $haystack
   *   An array of Ajax commands returned by the server.
   * @param $needle
   *   Array of info we're expecting in one of those commands.
   * @param $message
   *   An assertion message.
   */
  protected function assertCommand($haystack, $needle, $message) {
    $found = FALSE;
    foreach ($haystack as $command) {
      // If the command has additional settings that we're not testing for, do
      // not consider that a failure.
      if (isset($command['settings']) && is_array($command['settings']) && isset($needle['settings']) && is_array($needle['settings'])) {
        $command['settings'] = array_intersect_key($command['settings'], $needle['settings']);
      }
      // If the command has additional data that we're not testing for, do not
      // consider that a failure. Also, == instead of ===, because we don't
      // require the key/value pairs to be in any particular order
      // (http://www.php.net/manual/en/language.operators.array.php).
      if (array_intersect_key($command, $needle) == $needle) {
        $found = TRUE;
        break;
      }
    }
    $this->assertTrue($found, $message);
  }
}

/**
 * Tests primary Ajax framework functions.
 */
class AJAXFrameworkTestCase extends AJAXTestCase {
  protected $profile = 'testing';

  public static function getInfo() {
    return array(
      'name' => 'AJAX framework',
      'description' => 'Performs tests on AJAX framework functions.',
      'group' => 'AJAX',
    );
  }

  /**
   * Test that ajax_render() returns JavaScript settings generated during the page request.
   *
   * @todo Add tests to ensure that ajax_render() returns commands for new CSS
   *   and JavaScript files to be loaded by the page. See
   *   http://drupal.org/node/561858.
   */
  function testAJAXRender() {
    $commands = $this->drupalGetAJAX('ajax-test/render');

    // Verify that there is a command to load settings added with
    // drupal_add_js().
    $expected = array(
      'command' => 'settings',
      'settings' => array('basePath' => base_path(), 'ajax' => 'test'),
    );
    $this->assertCommand($commands, $expected, t('ajax_render() loads settings added with drupal_add_js().'));

    // Verify that Ajax settings are loaded for #type 'link'.
    $this->drupalGet('ajax-test/link');
    $settings = $this->drupalGetSettings();
    $this->assertEqual($settings['ajax']['ajax-link']['url'], url('filter/tips'));
    $this->assertEqual($settings['ajax']['ajax-link']['wrapper'], 'block-system-main');
  }

  /**
   * Test behavior of ajax_render_error().
   */
  function testAJAXRenderError() {
    // Verify default error message.
    $commands = $this->drupalGetAJAX('ajax-test/render-error');
    $expected = array(
      'command' => 'alert',
      'text' => t('An error occurred while handling the request: The server received invalid input.'),
    );
    $this->assertCommand($commands, $expected, t('ajax_render_error() invokes alert command.'));

    // Verify custom error message.
    $edit = array(
      'message' => 'Custom error message.',
    );
    $commands = $this->drupalGetAJAX('ajax-test/render-error', array('query' => $edit));
    $expected = array(
      'command' => 'alert',
      'text' => $edit['message'],
    );
     $this->assertCommand($commands, $expected, t('Custom error message is output.'));
  }

  /**
   * Test that new JavaScript and CSS files added during an AJAX request are returned.
   */
  function testLazyLoad() {
    $expected = array(
      'setting_name' => 'ajax_forms_test_lazy_load_form_submit',
      'setting_value' => 'executed',
      'css' => drupal_get_path('module', 'system') . '/system.admin.css',
      'js' => drupal_get_path('module', 'system') . '/system.js',
    );
    // @todo D8: Add a drupal_css_defaults() helper function.
    $expected_css_html = drupal_get_css(array($expected['css'] => array(
      'type' => 'file',
      'group' => CSS_DEFAULT,
      'weight' => 0,
      'every_page' => FALSE,
      'media' => 'all',
      'preprocess' => TRUE,
      'data' => $expected['css'],
      'browsers' => array('IE' => TRUE, '!IE' => TRUE),
    )), TRUE);
    $expected_js_html = drupal_get_js('header', array($expected['js'] => drupal_js_defaults($expected['js'])), TRUE);

    // Get the base page.
    $this->drupalGet('ajax_forms_test_lazy_load_form');
    $original_settings = $this->drupalGetSettings();
    $original_css = $original_settings['ajaxPageState']['css'];
    $original_js = $original_settings['ajaxPageState']['js'];

    // Verify that the base page doesn't have the settings and files that are to
    // be lazy loaded as part of the next requests.
    $this->assertTrue(!isset($original_settings[$expected['setting_name']]), t('Page originally lacks the %setting, as expected.', array('%setting' => $expected['setting_name'])));
    $this->assertTrue(!isset($original_settings[$expected['css']]), t('Page originally lacks the %css file, as expected.', array('%css' => $expected['css'])));
    $this->assertTrue(!isset($original_settings[$expected['js']]), t('Page originally lacks the %js file, as expected.', array('%js' => $expected['js'])));

    // Submit the AJAX request without triggering files getting added.
    $commands = $this->drupalPostAJAX(NULL, array('add_files' => FALSE), array('op' => t('Submit')));
    $new_settings = $this->drupalGetSettings();

    // Verify the setting was not added when not expected.
    $this->assertTrue(!isset($new_settings['setting_name']), t('Page still lacks the %setting, as expected.', array('%setting' => $expected['setting_name'])));
    // Verify a settings command does not add CSS or scripts to Drupal.settings
    // and no command inserts the corresponding tags on the page.
    $found_settings_command = FALSE;
    $found_markup_command = FALSE;
    foreach ($commands as $command) {
      if ($command['command'] == 'settings' && (array_key_exists('css', $command['settings']['ajaxPageState']) || array_key_exists('js', $command['settings']['ajaxPageState']))) {
        $found_settings_command = TRUE;
      }
      if (isset($command['data']) && ($command['data'] == $expected_js_html || $command['data'] == $expected_css_html)) {
        $found_markup_command = TRUE;
      }
    }
    $this->assertFalse($found_settings_command, t('Page state still lacks the %css and %js files, as expected.', array('%css' => $expected['css'], '%js' => $expected['js'])));
    $this->assertFalse($found_markup_command, t('Page still lacks the %css and %js files, as expected.', array('%css' => $expected['css'], '%js' => $expected['js'])));

    // Submit the AJAX request and trigger adding files.
    $commands = $this->drupalPostAJAX(NULL, array('add_files' => TRUE), array('op' => t('Submit')));
    $new_settings = $this->drupalGetSettings();
    $new_css = $new_settings['ajaxPageState']['css'];
    $new_js = $new_settings['ajaxPageState']['js'];

    // Verify the expected setting was added.
    $this->assertIdentical($new_settings[$expected['setting_name']], $expected['setting_value'], t('Page now has the %setting.', array('%setting' => $expected['setting_name'])));

    // Verify the expected CSS file was added, both to Drupal.settings, and as
    // an AJAX command for inclusion into the HTML.
    $this->assertEqual($new_css, $original_css + array($expected['css'] => 1), t('Page state now has the %css file.', array('%css' => $expected['css'])));
    $this->assertCommand($commands, array('data' => $expected_css_html), t('Page now has the %css file.', array('%css' => $expected['css'])));

    // Verify the expected JS file was added, both to Drupal.settings, and as
    // an AJAX command for inclusion into the HTML. By testing for an exact HTML
    // string containing the SCRIPT tag, we also ensure that unexpected
    // JavaScript code, such as a jQuery.extend() that would potentially clobber
    // rather than properly merge settings, didn't accidentally get added.
    $this->assertEqual($new_js, $original_js + array($expected['js'] => 1), t('Page state now has the %js file.', array('%js' => $expected['js'])));
    $this->assertCommand($commands, array('data' => $expected_js_html), t('Page now has the %js file.', array('%js' => $expected['js'])));
  }

  /**
   * Tests that overridden CSS files are not added during lazy load.
   */
  function testLazyLoadOverriddenCSS() {
    // The test theme overrides system.base.css without an implementation,
    // thereby removing it.
    theme_enable(array('test_theme'));
    variable_set('theme_default', 'test_theme');

    // This gets the form, and emulates an Ajax submission on it, including
    // adding markup to the HEAD and BODY for any lazy loaded JS/CSS files.
    $this->drupalPostAJAX('ajax_forms_test_lazy_load_form', array('add_files' => TRUE), array('op' => t('Submit')));

    // Verify that the resulting HTML does not load the overridden CSS file.
    // We add a "?" to the assertion, because Drupal.settings may include
    // information about the file; we only really care about whether it appears
    // in a LINK or STYLE tag, for which Drupal always adds a query string for
    // cache control.
    $this->assertNoText('system.base.css?', 'Ajax lazy loading does not add overridden CSS files.');
  }
}

/**
 * Tests Ajax framework commands.
 */
class AJAXCommandsTestCase extends AJAXTestCase {
  public static function getInfo() {
    return array(
      'name' => 'AJAX commands',
      'description' => 'Performs tests on AJAX framework commands.',
      'group' => 'AJAX',
    );
  }

  /**
   * Test the various Ajax Commands.
   */
  function testAJAXCommands() {
    $form_path = 'ajax_forms_test_ajax_commands_form';
    $web_user = $this->drupalCreateUser(array('access content'));
    $this->drupalLogin($web_user);

    $edit = array();

    // Tests the 'after' command.
    $commands = $this->drupalPostAJAX($form_path, $edit, array('op' => t("AJAX 'After': Click to put something after the div")));
    $expected = array(
      'command' => 'insert',
      'method' => 'after',
      'data' => 'This will be placed after',
    );
    $this->assertCommand($commands, $expected, "'after' AJAX command issued with correct data");

    // Tests the 'alert' command.
    $commands = $this->drupalPostAJAX($form_path, $edit, array('op' => t("AJAX 'Alert': Click to alert")));
    $expected = array(
      'command' => 'alert',
      'text' => 'Alert',
    );
    $this->assertCommand($commands, $expected, "'alert' AJAX Command issued with correct text");

    // Tests the 'append' command.
    $commands = $this->drupalPostAJAX($form_path, $edit, array('op' => t("AJAX 'Append': Click to append something")));
    $expected = array(
      'command' => 'insert',
      'method' => 'append',
      'data' => 'Appended text',
    );
    $this->assertCommand($commands, $expected, "'append' AJAX command issued with correct data");

    // Tests the 'before' command.
    $commands = $this->drupalPostAJAX($form_path, $edit, array('op' => t("AJAX 'before': Click to put something before the div")));
    $expected = array(
      'command' => 'insert',
      'method' => 'before',
      'data' => 'Before text',
    );
    $this->assertCommand($commands, $expected, "'before' AJAX command issued with correct data");

    // Tests the 'changed' command.
    $commands = $this->drupalPostAJAX($form_path, $edit, array('op' => t("AJAX changed: Click to mark div changed.")));
    $expected = array(
      'command' => 'changed',
      'selector' => '#changed_div',
    );
    $this->assertCommand($commands, $expected, "'changed' AJAX command issued with correct selector");

    // Tests the 'changed' command using the second argument.
    $commands = $this->drupalPostAJAX($form_path, $edit, array('op' => t("AJAX changed: Click to mark div changed with asterisk.")));
    $expected = array(
      'command' => 'changed',
      'selector' => '#changed_div',
      'asterisk' => '#changed_div_mark_this',
    );
    $this->assertCommand($commands, $expected, "'changed' AJAX command (with asterisk) issued with correct selector");

    // Tests the 'css' command.
    $commands = $this->drupalPostAJAX($form_path, $edit, array('op' => t("Set the '#box' div to be blue.")));
    $expected = array(
      'command' => 'css',
      'selector' => '#css_div',
      'argument' => array('background-color' => 'blue'),
    );
    $this->assertCommand($commands, $expected, "'css' AJAX command issued with correct selector");

    // Tests the 'data' command.
    $commands = $this->drupalPostAJAX($form_path, $edit, array('op' => t("AJAX data command: Issue command.")));
    $expected = array(
      'command' => 'data',
      'name' => 'testkey',
      'value' => 'testvalue',
    );
    $this->assertCommand($commands, $expected, "'data' AJAX command issued with correct key and value");

    // Tests the 'invoke' command.
    $commands = $this->drupalPostAJAX($form_path, $edit, array('op' => t("AJAX invoke command: Invoke addClass() method.")));
    $expected = array(
      'command' => 'invoke',
      'method' => 'addClass',
      'arguments' => array('error'),
    );
    $this->assertCommand($commands, $expected, "'invoke' AJAX command issued with correct method and argument");

    // Tests the 'html' command.
    $commands = $this->drupalPostAJAX($form_path, $edit, array('op' => t("AJAX html: Replace the HTML in a selector.")));
    $expected = array(
      'command' => 'insert',
      'method' => 'html',
      'data' => 'replacement text',
    );
    $this->assertCommand($commands, $expected, "'html' AJAX command issued with correct data");

    // Tests the 'insert' command.
    $commands = $this->drupalPostAJAX($form_path, $edit, array('op' => t("AJAX insert: Let client insert based on #ajax['method'].")));
    $expected = array(
      'command' => 'insert',
      'data' => 'insert replacement text',
    );
    $this->assertCommand($commands, $expected, "'insert' AJAX command issued with correct data");

    // Tests the 'prepend' command.
    $commands = $this->drupalPostAJAX($form_path, $edit, array('op' => t("AJAX 'prepend': Click to prepend something")));
    $expected = array(
      'command' => 'insert',
      'method' => 'prepend',
      'data' => 'prepended text',
    );
    $this->assertCommand($commands, $expected, "'prepend' AJAX command issued with correct data");

    // Tests the 'remove' command.
    $commands = $this->drupalPostAJAX($form_path, $edit, array('op' => t("AJAX 'remove': Click to remove text")));
    $expected = array(
      'command' => 'remove',
      'selector' => '#remove_text',
    );
    $this->assertCommand($commands, $expected, "'remove' AJAX command issued with correct command and selector");

    // Tests the 'restripe' command.
    $commands = $this->drupalPostAJAX($form_path, $edit, array('op' => t("AJAX 'restripe' command")));
    $expected = array(
      'command' => 'restripe',
      'selector' => '#restripe_table',
    );
    $this->assertCommand($commands, $expected, "'restripe' AJAX command issued with correct selector");

    // Tests the 'settings' command.
    $commands = $this->drupalPostAJAX($form_path, $edit, array('op' => t("AJAX 'settings' command")));
    $expected = array(
      'command' => 'settings',
      'settings' => array('ajax_forms_test' => array('foo' => 42)),
    );
    $this->assertCommand($commands, $expected, "'settings' AJAX command issued with correct data");

    // Tests the 'add_css' command.
    $commands = $this->drupalPostAJAX($form_path, $edit, array('op' => t("AJAX 'add_css' command")));
    $expected = array(
      'command' => 'add_css',
      'data' => 'my/file.css',
    );
    $this->assertCommand($commands, $expected, "'add_css' AJAX command issued with correct data");
  }
}

/**
 * Test that $form_state['values'] is properly delivered to $ajax['callback'].
 */
class AJAXFormValuesTestCase extends AJAXTestCase {
  public static function getInfo() {
    return array(
      'name' => 'AJAX command form values',
      'description' => 'Tests that form values are properly delivered to AJAX callbacks.',
      'group' => 'AJAX',
    );
  }

  function setUp() {
    parent::setUp();

    $this->web_user = $this->drupalCreateUser(array('access content'));
    $this->drupalLogin($this->web_user);
  }

  /**
   * Create a simple form, then POST to system/ajax to change to it.
   */
  function testSimpleAJAXFormValue() {
    // Verify form values of a select element.
    foreach (array('red', 'green', 'blue') as $item) {
      $edit = array(
        'select' => $item,
      );
      $commands = $this->drupalPostAJAX('ajax_forms_test_get_form', $edit, 'select');
      $expected = array(
        'command' => 'data',
        'value' => $item,
      );
      $this->assertCommand($commands, $expected, "verification of AJAX form values from a selectbox issued with a correct value");
    }

    // Verify form values of a checkbox element.
    foreach (array(FALSE, TRUE) as $item) {
      $edit = array(
        'checkbox' => $item,
      );
      $commands = $this->drupalPostAJAX('ajax_forms_test_get_form', $edit, 'checkbox');
      $expected = array(
        'command' => 'data',
        'value' => (int) $item,
      );
      $this->assertCommand($commands, $expected, "verification of AJAX form values from a checkbox issued with a correct value");
    }
  }
}

/**
 * Tests that Ajax-enabled forms work when multiple instances of the same form are on a page.
 */
class AJAXMultiFormTestCase extends AJAXTestCase {
  public static function getInfo() {
    return array(
      'name' => 'AJAX multi form',
      'description' => 'Tests that AJAX-enabled forms work when multiple instances of the same form are on a page.',
      'group' => 'AJAX',
    );
  }

  function setUp() {
    parent::setUp(array('form_test'));

    // Create a multi-valued field for 'page' nodes to use for Ajax testing.
    $field_name = 'field_ajax_test';
    $field = array(
      'field_name' => $field_name,
      'type' => 'text',
      'cardinality' => FIELD_CARDINALITY_UNLIMITED,
    );
    field_create_field($field);
    $instance = array(
      'field_name' => $field_name,
      'entity_type' => 'node',
      'bundle' => 'page',
    );
    field_create_instance($instance);

    // Login a user who can create 'page' nodes.
    $this->web_user = $this->drupalCreateUser(array('create page content'));
    $this->drupalLogin($this->web_user);
  }

  /**
   * Test that a page with the 'page_node_form' included twice works correctly.
   */
  function testMultiForm() {
    // HTML IDs for elements within the field are potentially modified with
    // each Ajax submission, but these variables are stable and help target the
    // desired elements.
    $field_name = 'field_ajax_test';
    $field_xpaths = array(
      'page-node-form' => '//form[@id="page-node-form"]//div[contains(@class, "field-name-field-ajax-test")]',
      'page-node-form--2' => '//form[@id="page-node-form--2"]//div[contains(@class, "field-name-field-ajax-test")]',
    );
    $button_name = $field_name . '_add_more';
    $button_value = t('Add another item');
    $button_xpath_suffix = '//input[@name="' . $button_name . '"]';
    $field_items_xpath_suffix = '//input[@type="text"]';

    // Ensure the initial page contains both node forms and the correct number
    // of field items and "add more" button for the multi-valued field within
    // each form.
    $this->drupalGet('form-test/two-instances-of-same-form');
    foreach ($field_xpaths as $form_html_id => $field_xpath) {
      $this->assert(count($this->xpath($field_xpath . $field_items_xpath_suffix)) == 1, t('Found the correct number of field items on the initial page.'));
      $this->assertFieldByXPath($field_xpath . $button_xpath_suffix, NULL, t('Found the "add more" button on the initial page.'));
    }
    $this->assertNoDuplicateIds(t('Initial page contains unique IDs'), 'Other');

    // Submit the "add more" button of each form twice. After each corresponding
    // page update, ensure the same as above.
    foreach ($field_xpaths as $form_html_id => $field_xpath) {
      for ($i = 0; $i < 2; $i++) {
        $this->drupalPostAJAX(NULL, array(), array($button_name => $button_value), 'system/ajax', array(), array(), $form_html_id);
        $this->assert(count($this->xpath($field_xpath . $field_items_xpath_suffix)) == $i+2, t('Found the correct number of field items after an AJAX submission.'));
        $this->assertFieldByXPath($field_xpath . $button_xpath_suffix, NULL, t('Found the "add more" button after an AJAX submission.'));
        $this->assertNoDuplicateIds(t('Updated page contains unique IDs'), 'Other');
      }
    }
  }
}

/**
 * Test Ajax forms when page caching for anonymous users is turned on.
 */
class AJAXFormPageCacheTestCase extends AJAXTestCase {
  protected $profile = 'testing';

  public static function getInfo() {
    return array(
      'name' => 'AJAX forms on cached pages',
      'description' => 'Tests that AJAX forms work properly for anonymous users on cached pages.',
      'group' => 'AJAX',
    );
  }

  public function setUp() {
    parent::setUp();

    variable_set('cache', TRUE);
  }

  /**
   * Return the build id of the current form.
   */
  protected function getFormBuildId() {
    $build_id_fields = $this->xpath('//input[@name="form_build_id"]');
    $this->assertEqual(count($build_id_fields), 1, 'One form build id field on the page');
    return (string) $build_id_fields[0]['value'];
  }

  /**
   * Create a simple form, then POST to system/ajax to change to it.
   */
  public function testSimpleAJAXFormValue() {
    $this->drupalGet('ajax_forms_test_get_form');
    $this->assertEqual($this->drupalGetHeader('X-Drupal-Cache'), 'MISS', 'Page was not cached.');
    $build_id_initial = $this->getFormBuildId();

    $edit = array('select' => 'green');
    $commands = $this->drupalPostAJAX(NULL, $edit, 'select');
    $build_id_first_ajax = $this->getFormBuildId();
    $this->assertNotEqual($build_id_initial, $build_id_first_ajax, 'Build id is changed in the simpletest-DOM on first AJAX submission');
    $expected = array(
      'command' => 'updateBuildId',
      'old' => $build_id_initial,
      'new' => $build_id_first_ajax,
    );
    $this->assertCommand($commands, $expected, 'Build id change command issued on first AJAX submission');

    $edit = array('select' => 'red');
    $commands = $this->drupalPostAJAX(NULL, $edit, 'select');
    $build_id_second_ajax = $this->getFormBuildId();
    $this->assertEqual($build_id_first_ajax, $build_id_second_ajax, 'Build id remains the same on subsequent AJAX submissions');

    // Repeat the test sequence but this time with a page loaded from the cache.
    $this->drupalGet('ajax_forms_test_get_form');
    $this->assertEqual($this->drupalGetHeader('X-Drupal-Cache'), 'HIT', 'Page was cached.');
    $build_id_from_cache_initial = $this->getFormBuildId();
    $this->assertEqual($build_id_initial, $build_id_from_cache_initial, 'Build id is the same as on the first request');

    $edit = array('select' => 'green');
    $commands = $this->drupalPostAJAX(NULL, $edit, 'select');
    $build_id_from_cache_first_ajax = $this->getFormBuildId();
    $this->assertNotEqual($build_id_from_cache_initial, $build_id_from_cache_first_ajax, 'Build id is changed in the simpletest-DOM on first AJAX submission');
    $this->assertNotEqual($build_id_first_ajax, $build_id_from_cache_first_ajax, 'Build id from first user is not reused');
    $expected = array(
      'command' => 'updateBuildId',
      'old' => $build_id_from_cache_initial,
      'new' => $build_id_from_cache_first_ajax,
    );
    $this->assertCommand($commands, $expected, 'Build id change command issued on first AJAX submission');

    $edit = array('select' => 'red');
    $commands = $this->drupalPostAJAX(NULL, $edit, 'select');
    $build_id_from_cache_second_ajax = $this->getFormBuildId();
    $this->assertEqual($build_id_from_cache_first_ajax, $build_id_from_cache_second_ajax, 'Build id remains the same on subsequent AJAX submissions');
  }
}


/**
 * Miscellaneous Ajax tests using ajax_test module.
 */
class AJAXElementValidation extends AJAXTestCase {
  public static function getInfo() {
    return array(
      'name' => 'Miscellaneous AJAX tests',
      'description' => 'Various tests of AJAX behavior',
      'group' => 'AJAX',
    );
  }

  /**
   * Try to post an Ajax change to a form that has a validated element.
   *
   * The drivertext field is Ajax-enabled. An additional field is not, but
   * is set to be a required field. In this test the required field is not
   * filled in, and we want to see if the activation of the "drivertext"
   * Ajax-enabled field fails due to the required field being empty.
   */
  function testAJAXElementValidation() {
    $web_user = $this->drupalCreateUser();
    $edit = array('drivertext' => t('some dumb text'));

    // Post with 'drivertext' as the triggering element.
    $post_result = $this->drupalPostAJAX('ajax_validation_test', $edit, 'drivertext');
    // Look for a validation failure in the resultant JSON.
    $this->assertNoText(t('Error message'), "No error message in resultant JSON");
    $this->assertText('ajax_forms_test_validation_form_callback invoked', 'The correct callback was invoked');
  }
}