ffdn.org/sites/all/modules/captcha/image_captcha/image_captcha.test

<?php

/**
 * @file
 * Tests for the Image CAPTCHA module.
 */

class ImageCaptchaWebTestCase extends CaptchaBaseWebTestCase {

  public static function getInfo() {
    return array(
      'name' => 'General Image CAPTCHA functionality',
      'description' => 'Testing of the basic Image CAPTCHA functions.',
      'group' => 'CAPTCHA',
    );
  }

  public function setUp() {
    parent::setUp('image_captcha');
  }

  /**
   * Helper function to get the CAPTCHA image element from the current form.
   */
  protected function getCaptchaImageFromForm() {
    $elements = $this->xpath('//input[@name="captcha_sid"]/../img');
    return $elements[0];
  }

  /**
   * Helper function to get a CAPTCHA form.
   */
  protected function getImageCaptchaForm($form_id = 'user_login', $page = 'user') {
    // Set a CAPTCHA on supplied form.
    captcha_set_form_id_setting($form_id, 'image_captcha/Image');

    // Fetch the page and make sure that we got a CAPTCHA.
    $this->drupalGet($page);
    $this->assertCaptchaPresence(TRUE);
  }

  /**
   * Asserts that the image URL actually returns an image.
   */
  protected function assertNonEmptyImage() {
    $img = $this->getCaptchaImageFromForm();

    // Try to fetch the image.
    $this->drupalGet($this->getAbsoluteUrl($img['src']));
    $this->assertTrue($this->drupalGetHeader('Content-Length') > 0,
                      'Image CAPTCHA image is not empty.');
  }

  /**
   * Tests if the image URL actually returns an image with clean URLs enabled.
   */
  public function testNonEmptyImageCleanURLs() {
    variable_set('clean_url', 1);
    $this->getImageCaptchaForm();
    $this->assertNonEmptyImage();
  }

  /**
   * Tests if the image URL actually returns an image with clean URLs disabled.
   */
  public function testNonEmptyImageDirtyURLs() {
    variable_set('clean_url', 0);
    $this->getImageCaptchaForm();
    $this->assertNonEmptyImage();
  }

}