JavaScriptTest.php

<?php

/**
 * @file
 * Definition of Drupal\system\Tests\Common\JavaScriptTest.
 */
namespace Drupal\system\Tests\Common;

use Drupal\simpletest\WebTestBase;

/**
 * Tests the JavaScript system.
 */
class JavaScriptTest extends WebTestBase {

  /**
   * Enable Language and SimpleTest in the test environment.
   *
   * @var array
   */
  public static $modules = array(
    'language',
    'simpletest',
    'common_test',
    'path',
  );

  /**
   * Stores configured value for JavaScript preprocessing.
   */
  protected $preprocess_js = NULL;
  public static function getInfo() {
    return array(
      'name' => 'JavaScript',
      'description' => 'Tests the JavaScript system.',
      'group' => 'Common',
    );
  }
  function setUp() {
    parent::setUp();

    // Disable preprocessing
    $config = config('system.performance');
    $this->preprocess_js = $config
      ->get('js.preprocess');
    $config
      ->set('js.preprocess', 0);
    $config
      ->save();

    // Reset drupal_add_js() and drupal_add_library() statics before each test.
    drupal_static_reset('drupal_add_js');
    drupal_static_reset('drupal_add_library');
  }
  function tearDown() {

    // Restore configured value for JavaScript preprocessing.
    $config = config('system.performance');
    $config
      ->set('js.preprocess', $this->preprocess_js);
    $config
      ->save();
    parent::tearDown();
  }

  /**
   * Tests that default JavaScript is empty.
   */
  function testDefault() {
    $this
      ->assertEqual(array(), drupal_add_js(), 'Default JavaScript is empty.');
  }

  /**
   * Tests adding a JavaScript file.
   */
  function testAddFile() {
    $javascript = drupal_add_js('core/misc/collapse.js');
    $this
      ->assertTrue(array_key_exists('core/misc/collapse.js', $javascript), 'JavaScript files are correctly added.');
  }

  /**
   * Tests adding settings.
   */
  function testAddSetting() {

    // Add a file in order to test default settings.
    drupal_add_library('system', 'drupalSettings');
    $javascript = drupal_add_js();
    $last_settings = reset($javascript['settings']['data']);
    $this
      ->assertTrue($last_settings['currentPath'], 'The current path JavaScript setting is set correctly.');
    $javascript = drupal_add_js(array(
      'drupal' => 'rocks',
      'dries' => 280342800,
    ), 'setting');
    $last_settings = end($javascript['settings']['data']);
    $this
      ->assertEqual(280342800, $last_settings['dries'], 'JavaScript setting is set correctly.');
    $this
      ->assertEqual('rocks', $last_settings['drupal'], 'The other JavaScript setting is set correctly.');
  }

  /**
   * Tests adding an external JavaScript File.
   */
  function testAddExternal() {
    $path = 'http://example.com/script.js';
    $javascript = drupal_add_js($path, 'external');
    $this
      ->assertTrue(array_key_exists('http://example.com/script.js', $javascript), 'Added an external JavaScript file.');
  }

  /**
   * Tests adding JavaScript files with additional attributes.
   */
  function testAttributes() {
    $default_query_string = variable_get('css_js_query_string', '0');
    drupal_add_library('system', 'drupal');
    drupal_add_js('http://example.com/script.js', array(
      'attributes' => array(
        'defer' => 'defer',
      ),
    ));
    drupal_add_js('core/misc/collapse.js', array(
      'attributes' => array(
        'defer' => 'defer',
      ),
    ));
    $javascript = drupal_get_js();
    $expected_1 = '<script src="http://example.com/script.js?' . $default_query_string . '" defer="defer"></script>';
    $expected_2 = '<script src="' . file_create_url('core/misc/collapse.js') . '?' . $default_query_string . '" defer="defer"></script>';
    $this
      ->assertTrue(strpos($javascript, $expected_1) > 0, 'Rendered external JavaScript with correct defer attribute.');
    $this
      ->assertTrue(strpos($javascript, $expected_2) > 0, 'Rendered internal JavaScript with correct defer attribute.');
  }

  /**
   * Tests that attributes are maintained when JS aggregation is enabled.
   */
  function testAggregatedAttributes() {

    // Enable aggregation.
    config('system.performance')
      ->set('js.preprocess', 1)
      ->save();
    $default_query_string = variable_get('css_js_query_string', '0');
    drupal_add_library('system', 'drupal');
    drupal_add_js('http://example.com/script.js', array(
      'attributes' => array(
        'defer' => 'defer',
      ),
    ));
    drupal_add_js('core/misc/collapse.js', array(
      'attributes' => array(
        'defer' => 'defer',
      ),
    ));
    $javascript = drupal_get_js();
    $expected_1 = '<script src="http://example.com/script.js?' . $default_query_string . '" defer="defer"></script>';
    $expected_2 = '<script src="' . file_create_url('core/misc/collapse.js') . '?' . $default_query_string . '" defer="defer"></script>';
    $this
      ->assertTrue(strpos($javascript, $expected_1) > 0, 'Rendered external JavaScript with correct defer attribute with aggregation enabled.');
    $this
      ->assertTrue(strpos($javascript, $expected_2) > 0, 'Rendered internal JavaScript with correct defer attribute with aggregation enabled.');
  }

  /**
   * Tests drupal_get_js() for JavaScript settings.
   */
  function testHeaderSetting() {
    drupal_add_library('system', 'drupalSettings');
    $javascript = drupal_get_js('header');
    $this
      ->assertTrue(strpos($javascript, 'basePath') > 0, 'Rendered JavaScript header returns basePath setting.');
    $this
      ->assertTrue(strpos($javascript, 'scriptPath') > 0, 'Rendered JavaScript header returns scriptPath setting.');
    $this
      ->assertTrue(strpos($javascript, 'pathPrefix') > 0, 'Rendered JavaScript header returns pathPrefix setting.');
    $this
      ->assertTrue(strpos($javascript, 'currentPath') > 0, 'Rendered JavaScript header returns currentPath setting.');

    // Only the second of these two entries should appear in Drupal.settings.
    drupal_add_js(array(
      'commonTest' => 'commonTestShouldNotAppear',
    ), 'setting');
    drupal_add_js(array(
      'commonTest' => 'commonTestShouldAppear',
    ), 'setting');

    // All three of these entries should appear in Drupal.settings.
    drupal_add_js(array(
      'commonTestArray' => array(
        'commonTestValue0',
      ),
    ), 'setting');
    drupal_add_js(array(
      'commonTestArray' => array(
        'commonTestValue1',
      ),
    ), 'setting');
    drupal_add_js(array(
      'commonTestArray' => array(
        'commonTestValue2',
      ),
    ), 'setting');

    // Only the second of these two entries should appear in Drupal.settings.
    drupal_add_js(array(
      'commonTestArray' => array(
        'key' => 'commonTestOldValue',
      ),
    ), 'setting');
    drupal_add_js(array(
      'commonTestArray' => array(
        'key' => 'commonTestNewValue',
      ),
    ), 'setting');
    $javascript = drupal_get_js('header');

    // Test whether drupal_add_js can be used to override a previous setting.
    $this
      ->assertTrue(strpos($javascript, 'commonTestShouldAppear') > 0, 'Rendered JavaScript header returns custom setting.');
    $this
      ->assertTrue(strpos($javascript, 'commonTestShouldNotAppear') === FALSE, 'drupal_add_js() correctly overrides a custom setting.');

    // Test whether drupal_add_js can be used to add numerically indexed values
    // to an array.
    $array_values_appear = strpos($javascript, 'commonTestValue0') > 0 && strpos($javascript, 'commonTestValue1') > 0 && strpos($javascript, 'commonTestValue2') > 0;
    $this
      ->assertTrue($array_values_appear, 'drupal_add_js() correctly adds settings to the end of an indexed array.');

    // Test whether drupal_add_js can be used to override the entry for an
    // existing key in an associative array.
    $associative_array_override = strpos($javascript, 'commonTestNewValue') > 0 && strpos($javascript, 'commonTestOldValue') === FALSE;
    $this
      ->assertTrue($associative_array_override, 'drupal_add_js() correctly overrides settings within an associative array.');

    // Check in a rendered page.
    $this
      ->drupalGet('common-test/query-string');
    $this
      ->assertPattern('@<script>.+drupalSettings.+"currentPath":"common-test\\\\/query-string"@s', 'currentPath is in the JS settings');
    $path = array(
      'source' => 'common-test/query-string',
      'alias' => 'common-test/currentpath-check',
    );
    drupal_container()
      ->get('path.crud')
      ->save($path['source'], $path['alias']);
    $this
      ->drupalGet('common-test/currentpath-check');
    $this
      ->assertPattern('@<script>.+drupalSettings.+"currentPath":"common-test\\\\/query-string"@s', 'currentPath is in the JS settings for an aliased path');
  }

  /**
   * Tests to see if resetting the JavaScript empties the cache.
   */
  function testReset() {
    drupal_add_library('system', 'drupal');
    drupal_add_js('core/misc/collapse.js');
    drupal_static_reset('drupal_add_js');
    $this
      ->assertEqual(array(), drupal_add_js(), 'Resetting the JavaScript correctly empties the cache.');
  }

  /**
   * Tests adding inline scripts.
   */
  function testAddInline() {
    drupal_add_library('system', 'drupal');
    $inline = 'jQuery(function () { });';
    $javascript = drupal_add_js($inline, array(
      'type' => 'inline',
      'scope' => 'footer',
    ));
    $this
      ->assertTrue(array_key_exists('core/misc/jquery.js', $javascript), 'jQuery is added when inline scripts are added.');
    $data = end($javascript);
    $this
      ->assertEqual($inline, $data['data'], 'Inline JavaScript is correctly added to the footer.');
  }

  /**
   * Tests rendering an external JavaScript file.
   */
  function testRenderExternal() {
    drupal_add_library('system', 'drupal');
    $external = 'http://example.com/example.js';
    drupal_add_js($external, 'external');
    $javascript = drupal_get_js();

    // Local files have a base_path() prefix, external files should not.
    $this
      ->assertTrue(strpos($javascript, 'src="' . $external) > 0, 'Rendering an external JavaScript file.');
  }

  /**
   * Tests drupal_get_js() with a footer scope.
   */
  function testFooterHTML() {
    drupal_add_library('system', 'drupal');
    $inline = 'jQuery(function () { });';
    drupal_add_js($inline, array(
      'type' => 'inline',
      'scope' => 'footer',
    ));
    $javascript = drupal_get_js('footer');
    $this
      ->assertTrue(strpos($javascript, $inline) > 0, 'Rendered JavaScript footer returns the inline code.');
  }

  /**
   * Tests drupal_add_js() sets preproccess to FALSE when cache is also FALSE.
   */
  function testNoCache() {
    drupal_add_library('system', 'drupal');
    $javascript = drupal_add_js('core/misc/collapse.js', array(
      'cache' => FALSE,
    ));
    $this
      ->assertFalse($javascript['core/misc/collapse.js']['preprocess'], 'Setting cache to FALSE sets proprocess to FALSE when adding JavaScript.');
  }

  /**
   * Tests adding a JavaScript file with a different group.
   */
  function testDifferentGroup() {
    drupal_add_library('system', 'drupal');
    $javascript = drupal_add_js('core/misc/collapse.js', array(
      'group' => JS_THEME,
    ));
    $this
      ->assertEqual($javascript['core/misc/collapse.js']['group'], JS_THEME, 'Adding a JavaScript file with a different group caches the given group.');
  }

  /**
   * Tests adding a JavaScript file with a different weight.
   */
  function testDifferentWeight() {
    $javascript = drupal_add_js('core/misc/collapse.js', array(
      'weight' => 2,
    ));
    $this
      ->assertEqual($javascript['core/misc/collapse.js']['weight'], 2, 'Adding a JavaScript file with a different weight caches the given weight.');
  }

  /**
   * Tests adding JavaScript within conditional comments.
   *
   * @see drupal_pre_render_conditional_comments()
   */
  function testBrowserConditionalComments() {
    $default_query_string = variable_get('css_js_query_string', '0');
    drupal_add_library('system', 'drupal');
    drupal_add_js('core/misc/collapse.js', array(
      'browsers' => array(
        'IE' => 'lte IE 8',
        '!IE' => FALSE,
      ),
    ));
    drupal_add_js('jQuery(function () { });', array(
      'type' => 'inline',
      'browsers' => array(
        'IE' => FALSE,
      ),
    ));
    $javascript = drupal_get_js();
    $expected_1 = "<!--[if lte IE 8]>\n" . '<script src="' . file_create_url('core/misc/collapse.js') . '?' . $default_query_string . '"></script>' . "\n<![endif]-->";
    $expected_2 = "<!--[if !IE]><!-->\n" . '<script>' . "\n<!--//--><![CDATA[//><!--\n" . 'jQuery(function () { });' . "\n//--><!]]>\n" . '</script>' . "\n<!--<![endif]-->";
    $this
      ->assertTrue(strpos($javascript, $expected_1) > 0, 'Rendered JavaScript within downlevel-hidden conditional comments.');
    $this
      ->assertTrue(strpos($javascript, $expected_2) > 0, 'Rendered JavaScript within downlevel-revealed conditional comments.');
  }

  /**
   * Tests JavaScript versioning.
   */
  function testVersionQueryString() {
    drupal_add_library('system', 'drupal');
    drupal_add_js('core/misc/collapse.js', array(
      'version' => 'foo',
    ));
    drupal_add_js('core/misc/ajax.js', array(
      'version' => 'bar',
    ));
    $javascript = drupal_get_js();
    $this
      ->assertTrue(strpos($javascript, 'core/misc/collapse.js?v=foo') > 0 && strpos($javascript, 'core/misc/ajax.js?v=bar') > 0, 'JavaScript version identifiers correctly appended to URLs');
  }

  /**
   * Tests JavaScript grouping and aggregation.
   */
  function testAggregation() {
    $default_query_string = variable_get('css_js_query_string', '0');

    // To optimize aggregation, items with the 'every_page' option are ordered
    // ahead of ones without. The order of JavaScript execution must be the
    // same regardless of whether aggregation is enabled, so ensure this
    // expected order, first with aggregation off.
    drupal_add_library('system', 'drupal');
    drupal_add_js('core/misc/ajax.js');
    drupal_add_js('core/misc/collapse.js', array(
      'every_page' => TRUE,
    ));
    drupal_add_js('core/misc/autocomplete.js');
    drupal_add_js('core/misc/batch.js', array(
      'every_page' => TRUE,
    ));
    $javascript = drupal_get_js();
    $expected = implode("\n", array(
      '<script src="' . file_create_url('core/misc/collapse.js') . '?' . $default_query_string . '"></script>',
      '<script src="' . file_create_url('core/misc/batch.js') . '?' . $default_query_string . '"></script>',
      '<script src="' . file_create_url('core/misc/ajax.js') . '?' . $default_query_string . '"></script>',
      '<script src="' . file_create_url('core/misc/autocomplete.js') . '?' . $default_query_string . '"></script>',
    ));
    $this
      ->assertTrue(strpos($javascript, $expected) > 0, 'Unaggregated JavaScript is added in the expected group order.');

    // Now ensure that with aggregation on, one file is made for the
    // 'every_page' files, and one file is made for the others.
    drupal_static_reset('drupal_add_js');
    $config = config('system.performance');
    $config
      ->set('js.preprocess', 1);
    $config
      ->save();
    drupal_add_library('system', 'drupal');
    drupal_add_js('core/misc/ajax.js');
    drupal_add_js('core/misc/collapse.js', array(
      'every_page' => TRUE,
    ));
    drupal_add_js('core/misc/autocomplete.js');
    drupal_add_js('core/misc/batch.js', array(
      'every_page' => TRUE,
    ));
    $js_items = drupal_add_js();
    $javascript = drupal_get_js();
    $expected = implode("\n", array(
      '<script src="' . file_create_url(drupal_build_js_cache(array(
        'core/misc/collapse.js' => $js_items['core/misc/collapse.js'],
        'core/misc/batch.js' => $js_items['core/misc/batch.js'],
      ))) . '"></script>',
      '<script src="' . file_create_url(drupal_build_js_cache(array(
        'core/misc/ajax.js' => $js_items['core/misc/ajax.js'],
        'core/misc/autocomplete.js' => $js_items['core/misc/autocomplete.js'],
      ))) . '"></script>',
    ));
    $this
      ->assertTrue(strpos($javascript, $expected) !== FALSE, 'JavaScript is aggregated in the expected groups and order.');
  }

  /**
   * Tests JavaScript aggregation when files are added to a different scope.
   */
  function testAggregationOrder() {

    // Enable JavaScript aggregation.
    config('system.performance')
      ->set('js.preprocess', 1)
      ->save();
    drupal_static_reset('drupal_add_js');

    // Add two JavaScript files to the current request and build the cache.
    drupal_add_library('system', 'drupal');
    drupal_add_js('core/misc/ajax.js');
    drupal_add_js('core/misc/autocomplete.js');
    $js_items = drupal_add_js();
    drupal_build_js_cache(array(
      'core/misc/ajax.js' => $js_items['core/misc/ajax.js'],
      'core/misc/autocomplete.js' => $js_items['core/misc/autocomplete.js'],
    ));

    // Store the expected key for the first item in the cache.
    $cache = array_keys(state()
      ->get('system.js_cache_files') ?: array());
    $expected_key = $cache[0];

    // Reset variables and add a file in a different scope first.
    state()
      ->delete('system.js_cache_files');
    drupal_static_reset('drupal_add_js');
    drupal_add_library('system', 'drupal');
    drupal_add_js('some/custom/javascript_file.js', array(
      'scope' => 'footer',
    ));
    drupal_add_js('core/misc/ajax.js');
    drupal_add_js('core/misc/autocomplete.js');

    // Rebuild the cache.
    $js_items = drupal_add_js();
    drupal_build_js_cache(array(
      'core/misc/ajax.js' => $js_items['core/misc/ajax.js'],
      'core/misc/autocomplete.js' => $js_items['core/misc/autocomplete.js'],
    ));

    // Compare the expected key for the first file to the current one.
    $cache = array_keys(state()
      ->get('system.js_cache_files') ?: array());
    $key = $cache[0];
    $this
      ->assertEqual($key, $expected_key, 'JavaScript aggregation is not affected by ordering in different scopes.');
  }

  /**
   * Tests JavaScript ordering.
   */
  function testRenderOrder() {

    // Add a bunch of JavaScript in strange ordering.
    drupal_add_js('(function($){alert("Weight 5 #1");})(jQuery);', array(
      'type' => 'inline',
      'scope' => 'footer',
      'weight' => 5,
    ));
    drupal_add_js('(function($){alert("Weight 0 #1");})(jQuery);', array(
      'type' => 'inline',
      'scope' => 'footer',
    ));
    drupal_add_js('(function($){alert("Weight 0 #2");})(jQuery);', array(
      'type' => 'inline',
      'scope' => 'footer',
    ));
    drupal_add_js('(function($){alert("Weight -8 #1");})(jQuery);', array(
      'type' => 'inline',
      'scope' => 'footer',
      'weight' => -8,
    ));
    drupal_add_js('(function($){alert("Weight -8 #2");})(jQuery);', array(
      'type' => 'inline',
      'scope' => 'footer',
      'weight' => -8,
    ));
    drupal_add_js('(function($){alert("Weight -8 #3");})(jQuery);', array(
      'type' => 'inline',
      'scope' => 'footer',
      'weight' => -8,
    ));
    drupal_add_js('http://example.com/example.js?Weight -5 #1', array(
      'type' => 'external',
      'scope' => 'footer',
      'weight' => -5,
    ));
    drupal_add_js('(function($){alert("Weight -8 #4");})(jQuery);', array(
      'type' => 'inline',
      'scope' => 'footer',
      'weight' => -8,
    ));
    drupal_add_js('(function($){alert("Weight 5 #2");})(jQuery);', array(
      'type' => 'inline',
      'scope' => 'footer',
      'weight' => 5,
    ));
    drupal_add_js('(function($){alert("Weight 0 #3");})(jQuery);', array(
      'type' => 'inline',
      'scope' => 'footer',
    ));

    // Construct the expected result from the regex.
    $expected = array(
      "-8 #1",
      "-8 #2",
      "-8 #3",
      "-8 #4",
      "-5 #1",
      // The external script.
      "0 #1",
      "0 #2",
      "0 #3",
      "5 #1",
      "5 #2",
    );

    // Retrieve the rendered JavaScript and test against the regex.
    $js = drupal_get_js('footer');
    $matches = array();
    if (preg_match_all('/Weight\\s([-0-9]+\\s[#0-9]+)/', $js, $matches)) {
      $result = $matches[1];
    }
    else {
      $result = array();
    }
    $this
      ->assertIdentical($result, $expected, 'JavaScript is added in the expected weight order.');
  }

  /**
   * Tests rendering the JavaScript with a file's weight above jQuery's.
   */
  function testRenderDifferentWeight() {

    // JavaScript files are sorted first by group, then by the 'every_page'
    // flag, then by weight (see drupal_sort_css_js()), so to test the effect of
    // weight, we need the other two options to be the same.
    drupal_add_library('system', 'jquery');
    drupal_add_js('core/misc/collapse.js', array(
      'group' => JS_LIBRARY,
      'every_page' => TRUE,
      'weight' => -21,
    ));
    $javascript = drupal_get_js();
    $this
      ->assertTrue(strpos($javascript, 'core/misc/collapse.js') < strpos($javascript, 'core/misc/jquery.js'), 'Rendering a JavaScript file above jQuery.');
  }

  /**
   * Tests altering a JavaScript's weight via hook_js_alter().
   *
   * @see simpletest_js_alter()
   */
  function testAlter() {

    // Add both tableselect.js and simpletest.js, with a larger weight on SimpleTest.
    drupal_add_js('core/misc/tableselect.js');
    drupal_add_js(drupal_get_path('module', 'simpletest') . '/simpletest.js', array(
      'weight' => 9999,
    ));

    // Render the JavaScript, testing if simpletest.js was altered to be before
    // tableselect.js. See simpletest_js_alter() to see where this alteration
    // takes place.
    $javascript = drupal_get_js();
    $this
      ->assertTrue(strpos($javascript, 'simpletest.js') < strpos($javascript, 'core/misc/tableselect.js'), 'Altering JavaScript weight through the alter hook.');
  }

  /**
   * Adds a library to the page and tests for both its JavaScript and its CSS.
   */
  function testLibraryRender() {
    $result = drupal_add_library('system', 'jquery.farbtastic');
    $this
      ->assertTrue($result !== FALSE, 'Library was added without errors.');
    $scripts = drupal_get_js();
    $styles = drupal_get_css();
    $this
      ->assertTrue(strpos($scripts, 'core/misc/farbtastic/farbtastic.js'), 'JavaScript of library was added to the page.');
    $this
      ->assertTrue(strpos($styles, 'core/misc/farbtastic/farbtastic.css'), 'Stylesheet of library was added to the page.');
  }

  /**
   * Adds a JavaScript library to the page and alters it.
   *
   * @see common_test_library_info_alter()
   */
  function testLibraryAlter() {

    // Verify that common_test altered the title of Farbtastic.
    $library = drupal_get_library('system', 'jquery.farbtastic');
    $this
      ->assertEqual($library['title'], 'Farbtastic: Altered Library', 'Registered libraries were altered.');

    // common_test_library_info_alter() also added a dependency on jQuery Form.
    drupal_add_library('system', 'jquery.farbtastic');
    $scripts = drupal_get_js();
    $this
      ->assertTrue(strpos($scripts, 'core/misc/jquery.form.js'), 'Altered library dependencies are added to the page.');
  }

  /**
   * Tests that multiple modules can implement the same library.
   *
   * @see common_test_library_info()
   */
  function testLibraryNameConflicts() {
    $farbtastic = drupal_get_library('common_test', 'jquery.farbtastic');
    $this
      ->assertEqual($farbtastic['title'], 'Custom Farbtastic Library', 'Alternative libraries can be added to the page.');
  }

  /**
   * Tests non-existing libraries.
   */
  function testLibraryUnknown() {
    $result = drupal_get_library('unknown', 'unknown');
    $this
      ->assertFalse($result, 'Unknown library returned FALSE.');
    drupal_static_reset('drupal_get_library');
    $result = drupal_add_library('unknown', 'unknown');
    $this
      ->assertFalse($result, 'Unknown library returned FALSE.');
    $scripts = drupal_get_js();
    $this
      ->assertTrue(strpos($scripts, 'unknown') === FALSE, 'Unknown library was not added to the page.');
  }

  /**
   * Tests the addition of libraries through the #attached['library'] property.
   */
  function testAttachedLibrary() {
    $element['#attached']['library'][] = array(
      'system',
      'jquery.farbtastic',
    );
    drupal_render($element);
    $scripts = drupal_get_js();
    $this
      ->assertTrue(strpos($scripts, 'core/misc/farbtastic/farbtastic.js'), 'The attached_library property adds the additional libraries.');
  }

  /**
   * Tests retrieval of libraries via drupal_get_library().
   */
  function testGetLibrary() {

    // Retrieve all libraries registered by a module.
    $libraries = drupal_get_library('common_test');
    $this
      ->assertTrue(isset($libraries['jquery.farbtastic']), 'Retrieved all module libraries.');

    // Retrieve all libraries for a module not implementing hook_library_info().
    // Note: This test installs language module.
    $libraries = drupal_get_library('language');
    $this
      ->assertEqual($libraries, array(), 'Retrieving libraries from a module not implementing hook_library_info() returns an emtpy array.');

    // Retrieve a specific library by module and name.
    $farbtastic = drupal_get_library('common_test', 'jquery.farbtastic');
    $this
      ->assertEqual($farbtastic['version'], '5.3', 'Retrieved a single library.');

    // Retrieve a non-existing library by module and name.
    $farbtastic = drupal_get_library('common_test', 'foo');
    $this
      ->assertIdentical($farbtastic, FALSE, 'Retrieving a non-existing library returns FALSE.');
  }

  /**
   * Tests JavaScript files that have querystrings attached get added right.
   */
  function testAddJsFileWithQueryString() {
    $this
      ->drupalGet('common-test/query-string');
    $query_string = variable_get('css_js_query_string', '0');
    $this
      ->assertRaw(drupal_get_path('module', 'node') . '/node.js?' . $query_string, 'Query string was appended correctly to js.');
  }

}