diff --git a/lib/Drupal/libraries/Tests/LibrariesWebTest.php b/lib/Drupal/libraries/Tests/LibrariesWebTest.php
index 95a31a1..7b83759 100644
--- a/lib/Drupal/libraries/Tests/LibrariesWebTest.php
+++ b/lib/Drupal/libraries/Tests/LibrariesWebTest.php
@@ -107,11 +107,14 @@ class LibrariesWebTest extends WebTestBase {
    */
   function testLibrariesScanInfoFiles() {
     $expected = array('example_info_file' => (object) array(
-      'uri' => drupal_get_path('module', 'libraries') . '/tests/example/example_info_file.libraries.info',
-      'filename' => 'example_info_file.libraries.info',
-      'name' => 'example_info_file.libraries',
+      'uri' => drupal_get_path('module', 'libraries') . '/tests/example/example_info_file.libraries.info.yml',
+      'filename' => 'example_info_file.libraries.info.yml',
+      'name' => 'example_info_file.libraries.info',
     ));
-    $this->assertEqual(libraries_scan_info_files(), $expected, 'libraries_scan_info_files() correctly finds the example info file.');
+    $actual = libraries_scan_info_files();
+    $this->verbose('Expected:<pre>' . var_export($expected, TRUE) . '</pre>');
+    $this->verbose('Actual:<pre>' . var_export($actual, TRUE) . '</pre>');
+    $this->assertEqual($actual, $expected, 'libraries_scan_info_files() correctly finds the example info file.');
     $this->verbose('<pre>' . var_export(libraries_scan_info_files(), TRUE) . '</pre>');
   }
 
@@ -140,7 +143,7 @@ class LibrariesWebTest extends WebTestBase {
     // Test a library specified with an .info file gets detected.
     $expected = array(
       'name' => 'Example info file',
-      'info file' => drupal_get_path('module', 'libraries_test') . '/example/example_info_file.libraries.info',
+      'info file' => drupal_get_path('module', 'libraries') . '/tests/example/example_info_file.libraries.info.yml',
     );
     libraries_info_defaults($expected, 'example_info_file');
     $library = libraries_info('example_info_file');
@@ -451,7 +454,7 @@ class LibrariesWebTest extends WebTestBase {
     // DOM.
     $html = array(
       'js' => array('<script src="', '"></script>'),
-      'css' => array('@import url("', '");'),
+      'css' => array('<link rel="stylesheet" href="', '" media="all" />'),
       // PHP files do not get added to the DOM directly.
       // @see _libraries_test_load()
       'php' => array('<li>', '</li>'),
@@ -459,7 +462,7 @@ class LibrariesWebTest extends WebTestBase {
 
     foreach ($names as $name => $expected) {
       foreach ($extensions as $extension) {
-        $filepath = drupal_get_path('module', 'libraries_test') . "/example/$name.$extension";
+        $filepath = drupal_get_path('module', 'libraries') . "/tests/example/$name.$extension";
         // JavaScript and CSS files appear as full URLs and with an appended
         // query string.
         if (in_array($extension, array('js', 'css'))) {
@@ -477,5 +480,4 @@ class LibrariesWebTest extends WebTestBase {
       }
     }
   }
-
 }
diff --git a/libraries.info b/libraries.info
deleted file mode 100644
index 1a95710..0000000
--- a/libraries.info
+++ /dev/null
@@ -1,3 +0,0 @@
-name = Libraries
-description = Allows version-dependent and shared usage of external libraries.
-core = 8.x
diff --git a/libraries.info.yml b/libraries.info.yml
new file mode 100644
index 0000000..1891a6f
--- /dev/null
+++ b/libraries.info.yml
@@ -0,0 +1,4 @@
+name: Libraries
+type: module
+description: Allows version-dependent and shared usage of external libraries.
+core: 8.x
diff --git a/libraries.install b/libraries.install
deleted file mode 100644
index 9d7dd00..0000000
--- a/libraries.install
+++ /dev/null
@@ -1,15 +0,0 @@
-<?php
-
-/**
- * @file
- * Install, uninstall, and update functions for libraries.module.
- */
-
-/**
- * Implements hook_schema().
- */
-function libraries_schema() {
-  $schema['cache_libraries'] = drupal_get_schema_unprocessed('system', 'cache');
-  $schema['cache_libraries']['description'] = 'Cache table to store library information.';
-  return $schema;
-}
diff --git a/libraries.module b/libraries.module
index c3b291f..0f837b8 100644
--- a/libraries.module
+++ b/libraries.module
@@ -128,7 +128,7 @@ function libraries_scan_info_files() {
   $files = array();
   foreach ($directories as $dir) {
     if (file_exists($dir)) {
-      $files = array_merge($files, file_scan_directory($dir, '@^[a-z0-9._-]+\.libraries\.info$@', array(
+      $files = array_merge($files, file_scan_directory($dir, '@^[a-z0-9._-]+\.libraries\.info\.yml$@', array(
         'key' => 'name',
         'recurse' => FALSE,
       )));
@@ -136,7 +136,7 @@ function libraries_scan_info_files() {
   }
 
   foreach ($files as $filename => $file) {
-    $files[basename($filename, '.libraries')] = $file;
+    $files[basename($filename, '.libraries.info')] = $file;
     unset($files[$filename]);
   }
 
@@ -276,7 +276,7 @@ function libraries_prepare_files(&$library, $version = NULL, $variant = NULL) {
 function libraries_detect_dependencies(&$library, $version = NULL, $variant = NULL) {
   if (isset($library['dependencies'])) {
     foreach ($library['dependencies'] as &$dependency_string) {
-      $dependency_info = drupal_parse_dependency($dependency_string);
+      $dependency_info = libraries_parse_dependency($dependency_string);
       $dependency = libraries_detect($dependency_info['name']);
       if (!$dependency['installed']) {
         $library['installed'] = FALSE;
@@ -683,7 +683,7 @@ function libraries_load_files($library) {
         $data = "$path/$data";
         // Apply the default group if the group isn't explicitly given.
         if (!isset($options['group'])) {
-          $options['group'] = ($type == 'js') ? JS_DEFAULT : CSS_DEFAULT;
+          $options['group'] = ($type == 'js') ? JS_DEFAULT : CSS_AGGREGATE_DEFAULT;
         }
         call_user_func('drupal_add_' . $type, $data, $options);
         $count++;
@@ -753,3 +753,60 @@ function libraries_get_version($library, $options) {
   }
   fclose($file);
 }
+
+/**
+ * Parses a dependency for comparison by drupal_check_incompatibility().
+ *
+ * @param $dependency
+ *   A dependency string, for example 'foo (>=7.x-4.5-beta5, 3.x)'.
+ *
+ * @return
+ *   An associative array with three keys:
+ *   - 'name' includes the name of the thing to depend on (e.g. 'foo').
+ *   - 'original_version' contains the original version string (which can be
+ *     used in the UI for reporting incompatibilities).
+ *   - 'versions' is a list of associative arrays, each containing the keys
+ *     'op' and 'version'. 'op' can be one of: '=', '==', '!=', '<>', '<',
+ *     '<=', '>', or '>='. 'version' is one piece like '4.5-beta3'.
+ *   Callers should pass this structure to drupal_check_incompatibility().
+ *
+ */
+function libraries_parse_dependency($dependency) {
+  // We use named subpatterns and support every op that version_compare
+  // supports. Also, op is optional and defaults to equals.
+  $p_op = '(?P<operation>!=|==|=|<|<=|>|>=|<>)?';
+  // Core version is always optional: 7.x-2.x and 2.x is treated the same.
+  $p_core = '(?:' . preg_quote(DRUPAL_CORE_COMPATIBILITY) . '-)?';
+  $p_major = '(?P<major>\d+)';
+  // By setting the minor version to x, branches can be matched.
+  $p_minor = '(?P<minor>(?:\d+|x)(?:-[A-Za-z]+\d+)?)';
+  $value = array();
+  $parts = explode('(', $dependency, 2);
+  $value['name'] = trim($parts[0]);
+  if (isset($parts[1])) {
+    $value['original_version'] = ' (' . $parts[1];
+    foreach (explode(',', $parts[1]) as $version) {
+      if (preg_match("/^\s*$p_op\s*$p_core$p_major\.$p_minor/", $version, $matches)) {
+        $op = !empty($matches['operation']) ? $matches['operation'] : '=';
+        if ($matches['minor'] == 'x') {
+          // Drupal considers "2.x" to mean any version that begins with
+          // "2" (e.g. 2.0, 2.9 are all "2.x"). PHP's version_compare(),
+          // on the other hand, treats "x" as a string; so to
+          // version_compare(), "2.x" is considered less than 2.0. This
+          // means that >=2.x and <2.x are handled by version_compare()
+          // as we need, but > and <= are not.
+          if ($op == '>' || $op == '<=') {
+            $matches['major']++;
+          }
+          // Equivalence can be checked by adding two restrictions.
+          if ($op == '=' || $op == '==') {
+            $value['versions'][] = array('op' => '<', 'version' => ($matches['major'] + 1) . '.x');
+            $op = '>=';
+          }
+        }
+        $value['versions'][] = array('op' => $op, 'version' => $matches['major'] . '.' . $matches['minor']);
+      }
+    }
+  }
+  return $value;
+}
\ No newline at end of file
diff --git a/libraries.services.yml b/libraries.services.yml
new file mode 100644
index 0000000..bedb0b7
--- /dev/null
+++ b/libraries.services.yml
@@ -0,0 +1,8 @@
+services:
+  cache.libraries:
+    class: Drupal\Core\Cache\CacheBackendInterface
+    tags:
+      - { name: cache.bin }
+    factory_method: get
+    factory_service: cache_factory
+    arguments: [library]
\ No newline at end of file
diff --git a/libraries_test/lib/Drupal/libraries_test/Controller/ExampleController.php b/libraries_test/lib/Drupal/libraries_test/Controller/ExampleController.php
new file mode 100644
index 0000000..2ddb0a1
--- /dev/null
+++ b/libraries_test/lib/Drupal/libraries_test/Controller/ExampleController.php
@@ -0,0 +1,97 @@
+<?php
+
+/**
+ * @file
+ * Provides any admin-specific functionality
+ */
+
+namespace Drupal\libraries_test\Controller;
+
+use Drupal\Core\Controller\ControllerInterface;
+use Symfony\Component\DependencyInjection\ContainerInterface;
+
+class ExampleController implements ControllerInterface {
+  /**
+   * Injects BookManager Service.
+   */
+  public static function create(ContainerInterface $container) {
+    return new static();
+  }
+
+  /**
+   * Loads a specified library (variant) for testing.
+   *
+   * JavaScript and CSS files can be checked directly by SimpleTest, so we only
+   * need to manually check for PHP files. We provide information about the loaded
+   * JavaScript and CSS files for easier debugging. See example/README.txt for
+   * more information.
+   */
+  private function buildPage($library, $variant = NULL) {
+    libraries_load($library, $variant);
+    // JavaScript and CSS files can be checked directly by SimpleTest, so we only
+    // need to manually check for PHP files.
+    $output = '';
+
+    // For easer debugging of JS loading, a text is shown that the JavaScript will
+    // replace.
+    $output .= '<h2>JavaScript</h2>';
+    $output .= '<div class="libraries-test-javascript">';
+    $output .= 'If this text shows up, no JavaScript test file was loaded.';
+    $output .= '</div>';
+
+    // For easier debugging of CSS loading, the loaded CSS files will color the
+    // following text.
+    $output .= '<h2>CSS</h2>';
+    $output .= '<div class="libraries-test-css">';
+    $output .= 'If one of the CSS test files has been loaded, this text will be colored:';
+    $output .= '<ul>';
+    // Do not reference the actual CSS files (i.e. including '.css'), because that
+    // breaks testing.
+    $output .= '<li>example_1: red</li>';
+    $output .= '<li>example_2: green</li>';
+    $output .= '<li>example_3: orange</li>';
+    $output .= '<li>example_4: blue</li>';
+    $output .= '<li>libraries_test: purple</li>';
+    $output .= '</ul>';
+    $output .= '</div>';
+
+    $output .= '<h2>PHP</h2>';
+    $output .= '<div class="libraries-test-php">';
+    $output .= 'The following is a list of all loaded test PHP files:';
+    $output .= '<ul>';
+    $files = get_included_files();
+    foreach ($files as $file) {
+      if ((strpos($file, 'libraries/test') || strpos($file, 'libraries_test')) && !strpos($file, 'libraries_test.module') && !strpos($file, 'lib/Drupal/libraries_test')) {
+        $output .= '<li>' . str_replace(DRUPAL_ROOT . '/', '', $file) . '</li>';
+      }
+    }
+    $output .= '</ul>';
+    $output .= '</div>';
+
+    return $output;
+  }
+
+  public function files() {
+    return $this->buildPage('example_files');
+  }
+
+  public function integration() {
+    return $this->buildPage('example_integration_files');
+  }
+  
+  public function versions() {
+    return $this->buildPage('example_versions');
+  }
+  
+  public function variant() {
+    return $this->buildPage('example_variant', 'example_variant');
+  }
+  
+  public function versionsAndVariants() {
+    return $this->buildPage('example_versions_and_variants', 'example_variant_2');
+  }
+  
+  public function cache() {
+    return $this->buildPage('example_callback');
+  }
+}
\ No newline at end of file
diff --git a/libraries_test/libraries_test.css b/libraries_test/libraries_test.css
new file mode 100644
index 0000000..3505281
--- /dev/null
+++ b/libraries_test/libraries_test.css
@@ -0,0 +1,12 @@
+
+/**
+ * @file
+ * Test CSS file for Libraries loading.
+ *
+ * Color the 'libraries-test-css' div purple. See README.txt for more
+ * information.
+ */
+
+.libraries-test-css {
+  color: purple;
+}
diff --git a/libraries_test/libraries_test.inc b/libraries_test/libraries_test.inc
new file mode 100644
index 0000000..c0cf0dc
--- /dev/null
+++ b/libraries_test/libraries_test.inc
@@ -0,0 +1,11 @@
+<?php
+
+/**
+ * @file
+ * Test PHP file for Libraries loading.
+
+/**
+ * Dummy function to see if this file was loaded.
+ */
+function _libraries_test_integration_file() {
+}
diff --git a/libraries_test/libraries_test.info.yml b/libraries_test/libraries_test.info.yml
new file mode 100644
index 0000000..94f35c1
--- /dev/null
+++ b/libraries_test/libraries_test.info.yml
@@ -0,0 +1,7 @@
+name: Libraries test module
+type: module
+description: Tests library detection and loading.
+core: 8.x
+dependencies:
+  - libraries
+hidden: TRUE
diff --git a/libraries_test/libraries_test.js b/libraries_test/libraries_test.js
new file mode 100644
index 0000000..25ac3ec
--- /dev/null
+++ b/libraries_test/libraries_test.js
@@ -0,0 +1,18 @@
+
+/**
+ * @file
+ * Test JavaScript file for Libraries loading.
+ *
+ * Replace the text in the 'libraries-test-javascript' div. See README.txt for
+ * more information.
+ */
+
+(function ($) {
+
+Drupal.behaviors.librariesTest = {
+  attach: function(context, settings) {
+    $('.libraries-test-javascript').text('If this text shows up, libraries_test.js was loaded successfully.')
+  }
+};
+
+})(jQuery);
diff --git a/libraries_test/libraries_test.module b/libraries_test/libraries_test.module
new file mode 100644
index 0000000..5c25d02
--- /dev/null
+++ b/libraries_test/libraries_test.module
@@ -0,0 +1,495 @@
+<?php
+
+/**
+ * @file
+ * Tests the library detection and loading.
+ */
+
+/**
+ * Implements hook_libraries_info().
+ */
+function libraries_test_libraries_info() {
+  // Test library detection.
+  $libraries['example_missing'] = array(
+    'name' => 'Example missing',
+    'library path' => drupal_get_path('module', 'libraries') . '/tests/missing',
+  );
+  $libraries['example_undetected_version'] = array(
+    'name' => 'Example undetected version',
+    'library path' => drupal_get_path('module', 'libraries') . '/tests',
+    'version callback' => '_libraries_test_return_version',
+    'version arguments' => array(FALSE),
+  );
+  $libraries['example_unsupported_version'] = array(
+    'name' => 'Example unsupported version',
+    'library path' => drupal_get_path('module', 'libraries') . '/tests',
+    'version callback' => '_libraries_test_return_version',
+    'version arguments' => array('1'),
+    'versions' => array(
+      '2' => array(),
+    ),
+  );
+
+  $libraries['example_supported_version'] = array(
+    'name' => 'Example supported version',
+    'library path' => drupal_get_path('module', 'libraries') . '/tests',
+    'version callback' => '_libraries_test_return_version',
+    'version arguments' => array('1'),
+    'versions' => array(
+      '1' => array(),
+    ),
+  );
+
+  // Test the default version callback.
+  $libraries['example_default_version_callback'] = array(
+    'name' => 'Example default version callback',
+    'library path' => drupal_get_path('module', 'libraries') . '/tests/example',
+    'version arguments' => array(
+      'file' => 'README.txt',
+      // Version 1
+      'pattern' => '/Version (\d+)/',
+      'lines' => 5,
+    ),
+  );
+
+  // Test a multiple-parameter version callback.
+  $libraries['example_multiple_parameter_version_callback'] = array(
+    'name' => 'Example multiple parameter version callback',
+    'library path' => drupal_get_path('module', 'libraries') . '/tests/example',
+    // Version 1
+    'version callback' => '_libraries_test_get_version',
+    'version arguments' => array('README.txt', '/Version (\d+)/', 5),
+  );
+
+  // Test a top-level files property.
+  $libraries['example_files'] = array(
+    'name' => 'Example files',
+    'library path' => drupal_get_path('module', 'libraries') . '/tests/example',
+    'version' => '1',
+    'files' => array(
+      'js' => array('example_1.js'),
+      'css' => array('example_1.css'),
+      'php' => array('example_1.php'),
+    ),
+  );
+
+  // Test loading of integration files.
+  // Normally added by the corresponding module via hook_libraries_info_alter(),
+  // these files should be automatically loaded when the library is loaded.
+  $libraries['example_integration_files'] = array(
+    'name' => 'Example integration files',
+    'library path' => drupal_get_path('module', 'libraries') . '/tests/example',
+    'version' => '1',
+    'integration files' => array(
+      'libraries_test' => array(
+        'js' => array('libraries_test.js'),
+        'css' => array('libraries_test.css'),
+        'php' => array('libraries_test.inc'),
+      ),
+    ),
+  );
+
+  // Test version overloading.
+  $libraries['example_versions'] = array(
+    'name' => 'Example versions',
+    'library path' => drupal_get_path('module', 'libraries') . '/tests/example',
+    'version' => '2',
+    'versions' => array(
+      '1' => array(
+        'files' => array(
+          'js' => array('example_1.js'),
+          'css' => array('example_1.css'),
+          'php' => array('example_1.php'),
+        ),
+      ),
+      '2' => array(
+        'files' => array(
+          'js' => array('example_2.js'),
+          'css' => array('example_2.css'),
+          'php' => array('example_2.php'),
+        ),
+      ),
+    ),
+  );
+
+  // Test variant detection.
+  $libraries['example_variant_missing'] = array(
+    'name' => 'Example variant missing',
+    'library path' => drupal_get_path('module', 'libraries') . '/tests/example',
+    'version' => '1',
+    'variants' => array(
+      'example_variant' => array(
+        'files' => array(
+          'js' => array('example_3.js'),
+          'css' => array('example_3.css'),
+          'php' => array('example_3.php'),
+        ),
+        'variant callback' => '_libraries_test_return_installed',
+        'variant arguments' => array(FALSE),
+      ),
+    ),
+  );
+
+  $libraries['example_variant'] = array(
+    'name' => 'Example variant',
+    'library path' => drupal_get_path('module', 'libraries') . '/tests/example',
+    'version' => '1',
+    'variants' => array(
+      'example_variant' => array(
+        'files' => array(
+          'js' => array('example_3.js'),
+          'css' => array('example_3.css'),
+          'php' => array('example_3.php'),
+        ),
+        'variant callback' => '_libraries_test_return_installed',
+        'variant arguments' => array(TRUE),
+      ),
+    ),
+  );
+
+  // Test correct behaviour with multiple versions and multiple variants.
+  $libraries['example_versions_and_variants'] = array(
+    'name' => 'Example versions and variants',
+    'library path' => drupal_get_path('module', 'libraries') . '/tests/example',
+    'version' => '2',
+    'versions' => array(
+      '1' => array(
+        'variants' => array(
+          'example_variant_1' => array(
+            'files' => array(
+              'js' => array('example_1.js'),
+              'css' => array('example_1.css'),
+              'php' => array('example_1.php'),
+            ),
+            'variant callback' => '_libraries_test_return_installed',
+            'variant arguments' => array(TRUE),
+          ),
+          'example_variant_2' => array(
+            'files' => array(
+              'js' => array('example_2.js'),
+              'css' => array('example_2.css'),
+              'php' => array('example_2.php'),
+            ),
+            'variant callback' => '_libraries_test_return_installed',
+            'variant arguments' => array(TRUE),
+          ),
+        ),
+      ),
+      '2' => array(
+        'variants' => array(
+          'example_variant_1' => array(
+            'files' => array(
+              'js' => array('example_3.js'),
+              'css' => array('example_3.css'),
+              'php' => array('example_3.php'),
+            ),
+            'variant callback' => '_libraries_test_return_installed',
+            'variant arguments' => array(TRUE),
+          ),
+          'example_variant_2' => array(
+            'files' => array(
+              'js' => array('example_4.js'),
+              'css' => array('example_4.css'),
+              'php' => array('example_4.php'),
+            ),
+            'variant callback' => '_libraries_test_return_installed',
+            'variant arguments' => array(TRUE),
+          ),
+        ),
+      ),
+    ),
+  );
+
+  // Test dependency loading.
+  // We add one file to each library to be able to verify if it was loaded with
+  // libraries_load().
+  // This library acts as a dependency for the libraries below.
+  $libraries['example_dependency'] = array(
+    'name' => 'Example dependency',
+    'library path' => drupal_get_path('module', 'libraries') . '/tests/example',
+    'version' => '1.1',
+    'files' => array('js' => array('example_1.js')),
+  );
+  $libraries['example_dependency_missing'] = array(
+    'name' => 'Example dependency missing',
+    'library path' => drupal_get_path('module', 'libraries') . '/tests/example',
+    'version' => '1',
+    'dependencies' => array('example_missing'),
+    'files' => array('js' => array('example_1.js')),
+  );
+  $libraries['example_dependency_incompatible'] = array(
+    'name' => 'Example dependency incompatible',
+    'library path' => drupal_get_path('module', 'libraries') . '/tests/example',
+    'version' => '1',
+    'dependencies' => array('example_dependency (>1.1)'),
+    'files' => array('js' => array('example_1.js')),
+  );
+  $libraries['example_dependency_compatible'] = array(
+    'name' => 'Example dependency compatible',
+    'library path' => drupal_get_path('module', 'libraries') . '/tests/example',
+    'version' => '1',
+    'dependencies' => array('example_dependency (>=1.1)'),
+    'files' => array('js' => array('example_1.js')),
+  );
+
+  // Test the applying of callbacks.
+  $libraries['example_callback'] = array(
+    'name' => 'Example callback',
+    'library path' => drupal_get_path('module', 'libraries') . '/tests/example',
+    'version' => '1',
+    'versions' => array(
+      '1' => array(
+        'variants' => array(
+          'example_variant' => array(
+            // These keys are for testing purposes only.
+            'info callback' => 'not applied',
+            'pre-detect callback' => 'not applied',
+            'post-detect callback' => 'not applied',
+            'pre-load callback' => 'not applied',
+            'post-load callback' => 'not applied',
+          ),
+        ),
+        // These keys are for testing purposes only.
+        'info callback' => 'not applied',
+        'pre-detect callback' => 'not applied',
+        'post-detect callback' => 'not applied',
+        'pre-load callback' => 'not applied',
+        'post-load callback' => 'not applied',
+      ),
+    ),
+    'variants' => array(
+      'example_variant' => array(
+        // These keys are for testing purposes only.
+        'info callback' => 'not applied',
+        'pre-detect callback' => 'not applied',
+        'post-detect callback' => 'not applied',
+        'pre-load callback' => 'not applied',
+        'post-load callback' => 'not applied',
+      ),
+    ),
+    'callbacks' => array(
+      'info' => array('_libraries_test_info_callback'),
+      'pre-detect' => array('_libraries_test_pre_detect_callback'),
+      'post-detect' => array('_libraries_test_post_detect_callback'),
+      'pre-load' => array('_libraries_test_pre_load_callback'),
+      'post-load' => array('_libraries_test_post_load_callback'),
+    ),
+    // These keys are for testing purposes only.
+    'info callback' => 'not applied',
+    'pre-detect callback' => 'not applied',
+    'post-detect callback' => 'not applied',
+    'pre-load callback' => 'not applied',
+    'post-load callback' => 'not applied',
+  );
+
+  return $libraries;
+}
+
+/**
+ * Implements hook_libraries_info_file_paths()
+ */
+function libraries_test_libraries_info_file_paths() {
+  return array(drupal_get_path('module', 'libraries') . '/tests/example');
+}
+
+/**
+ * Gets the version of an example library.
+ *
+ * Returns exactly the version string entered as the $version parameter. This
+ * function cannot be collapsed with _libraries_test_return_installed(), because
+ * of the different arguments that are passed automatically.
+ */
+function _libraries_test_return_version($library, $version) {
+  return $version;
+}
+
+/**
+ * Gets the version information from an arbitrary library.
+ *
+ * Test function for a version callback with multiple arguments. This is an
+ * exact copy of libraries_get_version(), which uses a single $option argument,
+ * except for the fact that it uses multiple arguments. Since we support both
+ * type of version callbacks, detecting the version of a test library with this
+ * function ensures that the arguments are passed correctly. This function might
+ * be a useful reference for a custom version callback that uses multiple
+ * parameters.
+ *
+ * @param $library
+ *   An associative array containing all information about the library.
+ * @param $file
+ *   The filename to parse for the version, relative to the library path. For
+ *   example: 'docs/changelog.txt'.
+ * @param pattern
+ *   A string containing a regular expression (PCRE) to match the library
+ *   version. For example: '/@version (\d+)\.(\d+)/'.
+ * @param lines
+ *   (optional) The maximum number of lines to search the pattern in. Defaults
+ *   to 20.
+ * @param cols
+ *   (optional) The maximum number of characters per line to take into account.
+ *   Defaults to 200. In case of minified or compressed files, this prevents
+ *   reading the entire file into memory.
+ *
+ * @return
+ *   A string containing the version of the library.
+ *
+ * @see libraries_get_version()
+ */
+function _libraries_test_get_version($library, $file, $pattern, $lines = 20, $cols = 200) {
+
+  $file = DRUPAL_ROOT . '/' . $library['library path'] . '/' . $file;
+  if (!file_exists($file)) {
+    return;
+  }
+  $file = fopen($file, 'r');
+  while ($lines && $line = fgets($file, $cols)) {
+    if (preg_match($pattern, $line, $version)) {
+      fclose($file);
+      return $version[1];
+    }
+    $lines--;
+  }
+  fclose($file);
+}
+
+/**
+ * Detects the variant of an example library.
+ *
+ * Returns exactly the value of $installed, either TRUE or FALSE. This function
+ * cannot be collapsed with _libraries_test_return_version(), because of the
+ * different arguments that are passed automatically.
+ */
+function _libraries_test_return_installed($library, $name, $installed) {
+  return $installed;
+}
+
+/**
+ * Sets the 'info callback' key.
+ *
+ * This function is used as a test callback for the 'info' callback group.
+ *
+ * @see _libraries_test_callback()
+ */
+function _libraries_test_info_callback(&$library, $version, $variant) {
+  _libraries_test_callback($library, $version, $variant, 'info');
+}
+
+/**
+ * Sets the 'pre-detect callback' key.
+ *
+ * This function is used as a test callback for the 'pre-detect' callback group.
+ *
+ * @see _libraries_test_callback()
+ */
+function _libraries_test_pre_detect_callback(&$library, $version, $variant) {
+  _libraries_test_callback($library, $version, $variant, 'pre-detect');
+}
+
+/**
+ * Sets the 'post-detect callback' key.
+ *
+ * This function is used as a test callback for the 'post-detect callback group.
+ *
+ * @see _libraries_test_callback()
+ */
+function _libraries_test_post_detect_callback(&$library, $version, $variant) {
+  _libraries_test_callback($library, $version, $variant, 'post-detect');
+}
+
+/**
+ * Sets the 'pre-load callback' key.
+ *
+ * This function is used as a test callback for the 'pre-load' callback group.
+ *
+ * @see _libraries_test_callback()
+ */
+function _libraries_test_pre_load_callback(&$library, $version, $variant) {
+  _libraries_test_callback($library, $version, $variant, 'pre-load');
+}
+
+/**
+ * Sets the 'post-load callback' key.
+ *
+ * This function is used as a test callback for the 'post-load' callback group.
+ *
+ * @see _libraries_test_callback()
+ */
+function _libraries_test_post_load_callback(&$library, $version, $variant) {
+  _libraries_test_callback($library, $version, $variant, 'post-load');
+}
+
+/**
+ * Sets the '[group] callback' key, where [group] is prepare, detect, or load.
+ *
+ * This function is used as a test callback for the all callback groups.
+ *
+ * It sets the '[group] callback' (see above) key to 'applied ([part])' where
+ * [part] is either 'top-level', 'version x.y' (where x.y is the passed-in
+ * version string), 'variant example' (where example is the passed-in variant
+ * name), or 'version x.y, variant example' (see above), depending on the part
+ * of the library the passed-in library information belongs to.
+ *
+ * @param $library
+ *   An array of library information, which may be version- or variant-specific.
+ *   Passed by reference.
+ * @param $version
+ *   The version the library information passed in $library belongs to, or NULL
+ *   if the passed library information is not version-specific.
+ * @param $variant
+ *   The variant the library information passed in $library belongs to, or NULL
+ *   if the passed library information is not variant-specific.
+ */
+function _libraries_test_callback(&$library, $version, $variant, $group) {
+  $string = 'applied';
+  if (isset($version) && isset($variant)) {
+    $string .= " (version $version, variant $variant)";
+  }
+  elseif (isset($version)) {
+    $string .= " (version $version)";
+  }
+  elseif (isset($variant)) {
+    $string .= " (variant $variant)";
+  }
+  else {
+    $string .= ' (top-level)';
+  }
+  $library["$group callback"] = $string;
+
+  // The following is used to test caching of library information.
+  // Only set the message for the top-level library to prevent confusing,
+  // duplicate messages.
+  if (!isset($version) && !isset($variant) && variable_get('libraries_test_cache', FALSE)) {
+    drupal_set_message("The <em>$group</em> callback group was invoked.");
+  }
+}
+
+/**
+ * Implements hook_menu().
+ */
+function libraries_test_menu() {
+  $items['libraries_test/files'] = array(
+    'title' => 'Test files',
+    'route_name' => 'libraries_test_files',
+  );
+  $items['libraries_test/integration_files'] = array(
+    'title' => 'Test integration files',
+    'route_name' => 'libraries_test_integration_files',
+  );
+  $items['libraries_test/versions'] = array(
+    'title' => 'Test version loading',
+    'route_name' => 'libraries_test_versions',
+  );
+  $items['libraries_test/variant'] = array(
+    'title' => 'Test variant loading',
+    'route_name' => 'libraries_test_variant',
+  );
+  $items['libraries_test/versions_and_variants'] = array(
+    'title' => 'Test concurrent version and variant loading',
+    'route_name' => 'libraries_test_versions_and_variants',
+  );
+  $items['libraries_test/cache'] = array(
+    'title' => 'Test caching of library information',
+    'route_name' => 'libraries_test_cache',
+  );
+  return $items;
+}
diff --git a/libraries_test/libraries_test.routing.yml b/libraries_test/libraries_test.routing.yml
new file mode 100644
index 0000000..fe7dac4
--- /dev/null
+++ b/libraries_test/libraries_test.routing.yml
@@ -0,0 +1,36 @@
+libraries_test_files:
+  pattern: '/libraries_test/files'
+  defaults:
+    _content: Drupal\libraries_test\Controller\ExampleController::files
+  requirements:
+    _access: 'TRUE'
+libraries_test_integration_files:
+  pattern: '/libraries_test/integration_files'
+  defaults:
+    _content: Drupal\libraries_test\Controller\ExampleController::integration
+  requirements:
+    _access: 'TRUE'
+libraries_test_versions:
+  pattern: '/libraries_test/versions'
+  defaults:
+    _content: Drupal\libraries_test\Controller\ExampleController::versions
+  requirements:
+    _access: 'TRUE'
+libraries_test_variant:
+  pattern: '/libraries_test/variant'
+  defaults:
+    _content: Drupal\libraries_test\Controller\ExampleController::variant
+  requirements:
+    _access: 'TRUE'
+libraries_test_versions_and_variants:
+  pattern: '/libraries_test/versions_and_variants'
+  defaults:
+    _content: Drupal\libraries_test\Controller\ExampleController::versionsAndVariants
+  requirements:
+    _access: 'TRUE'
+libraries_test_cache:
+  pattern: '/libraries_test/cache'
+  defaults:
+    _content: Drupal\libraries_test\Controller\ExampleController::cache
+  requirements:
+    _access: 'TRUE'
diff --git a/tests/example/example_info_file.libraries.info b/tests/example/example_info_file.libraries.info
deleted file mode 100644
index ec255d4..0000000
--- a/tests/example/example_info_file.libraries.info
+++ /dev/null
@@ -1,4 +0,0 @@
-
-; This is an example info file of a library used for testing purposes.
-name = Example info file
-
diff --git a/tests/example/example_info_file.libraries.info.yml b/tests/example/example_info_file.libraries.info.yml
new file mode 100644
index 0000000..26086f4
--- /dev/null
+++ b/tests/example/example_info_file.libraries.info.yml
@@ -0,0 +1,4 @@
+
+# This is an example info file of a library used for testing purposes.
+name: Example info file
+
diff --git a/tests/libraries_test.css b/tests/libraries_test.css
deleted file mode 100644
index 3505281..0000000
--- a/tests/libraries_test.css
+++ /dev/null
@@ -1,12 +0,0 @@
-
-/**
- * @file
- * Test CSS file for Libraries loading.
- *
- * Color the 'libraries-test-css' div purple. See README.txt for more
- * information.
- */
-
-.libraries-test-css {
-  color: purple;
-}
diff --git a/tests/libraries_test.inc b/tests/libraries_test.inc
deleted file mode 100644
index c0cf0dc..0000000
--- a/tests/libraries_test.inc
+++ /dev/null
@@ -1,11 +0,0 @@
-<?php
-
-/**
- * @file
- * Test PHP file for Libraries loading.
-
-/**
- * Dummy function to see if this file was loaded.
- */
-function _libraries_test_integration_file() {
-}
diff --git a/tests/libraries_test.info b/tests/libraries_test.info
deleted file mode 100644
index 0f34b66..0000000
--- a/tests/libraries_test.info
+++ /dev/null
@@ -1,5 +0,0 @@
-name = Libraries test module
-description = Tests library detection and loading.
-core = 8.x
-dependencies[] = libraries
-hidden = TRUE
diff --git a/tests/libraries_test.js b/tests/libraries_test.js
deleted file mode 100644
index 25ac3ec..0000000
--- a/tests/libraries_test.js
+++ /dev/null
@@ -1,18 +0,0 @@
-
-/**
- * @file
- * Test JavaScript file for Libraries loading.
- *
- * Replace the text in the 'libraries-test-javascript' div. See README.txt for
- * more information.
- */
-
-(function ($) {
-
-Drupal.behaviors.librariesTest = {
-  attach: function(context, settings) {
-    $('.libraries-test-javascript').text('If this text shows up, libraries_test.js was loaded successfully.')
-  }
-};
-
-})(jQuery);
diff --git a/tests/libraries_test.module b/tests/libraries_test.module
deleted file mode 100644
index 67ed7f7..0000000
--- a/tests/libraries_test.module
+++ /dev/null
@@ -1,552 +0,0 @@
-<?php
-
-/**
- * @file
- * Tests the library detection and loading.
- */
-
-/**
- * Implements hook_libraries_info().
- */
-function libraries_test_libraries_info() {
-  // Test library detection.
-  $libraries['example_missing'] = array(
-    'name' => 'Example missing',
-    'library path' => drupal_get_path('module', 'libraries') . '/tests/missing',
-  );
-  $libraries['example_undetected_version'] = array(
-    'name' => 'Example undetected version',
-    'library path' => drupal_get_path('module', 'libraries') . '/tests',
-    'version callback' => '_libraries_test_return_version',
-    'version arguments' => array(FALSE),
-  );
-  $libraries['example_unsupported_version'] = array(
-    'name' => 'Example unsupported version',
-    'library path' => drupal_get_path('module', 'libraries') . '/tests',
-    'version callback' => '_libraries_test_return_version',
-    'version arguments' => array('1'),
-    'versions' => array(
-      '2' => array(),
-    ),
-  );
-
-  $libraries['example_supported_version'] = array(
-    'name' => 'Example supported version',
-    'library path' => drupal_get_path('module', 'libraries') . '/tests',
-    'version callback' => '_libraries_test_return_version',
-    'version arguments' => array('1'),
-    'versions' => array(
-      '1' => array(),
-    ),
-  );
-
-  // Test the default version callback.
-  $libraries['example_default_version_callback'] = array(
-    'name' => 'Example default version callback',
-    'library path' => drupal_get_path('module', 'libraries') . '/tests/example',
-    'version arguments' => array(
-      'file' => 'README.txt',
-      // Version 1
-      'pattern' => '/Version (\d+)/',
-      'lines' => 5,
-    ),
-  );
-
-  // Test a multiple-parameter version callback.
-  $libraries['example_multiple_parameter_version_callback'] = array(
-    'name' => 'Example multiple parameter version callback',
-    'library path' => drupal_get_path('module', 'libraries') . '/tests/example',
-    // Version 1
-    'version callback' => '_libraries_test_get_version',
-    'version arguments' => array('README.txt', '/Version (\d+)/', 5),
-  );
-
-  // Test a top-level files property.
-  $libraries['example_files'] = array(
-    'name' => 'Example files',
-    'library path' => drupal_get_path('module', 'libraries') . '/tests/example',
-    'version' => '1',
-    'files' => array(
-      'js' => array('example_1.js'),
-      'css' => array('example_1.css'),
-      'php' => array('example_1.php'),
-    ),
-  );
-
-  // Test loading of integration files.
-  // Normally added by the corresponding module via hook_libraries_info_alter(),
-  // these files should be automatically loaded when the library is loaded.
-  $libraries['example_integration_files'] = array(
-    'name' => 'Example integration files',
-    'library path' => drupal_get_path('module', 'libraries') . '/tests/example',
-    'version' => '1',
-    'integration files' => array(
-      'libraries_test' => array(
-        'js' => array('libraries_test.js'),
-        'css' => array('libraries_test.css'),
-        'php' => array('libraries_test.inc'),
-      ),
-    ),
-  );
-
-  // Test version overloading.
-  $libraries['example_versions'] = array(
-    'name' => 'Example versions',
-    'library path' => drupal_get_path('module', 'libraries') . '/tests/example',
-    'version' => '2',
-    'versions' => array(
-      '1' => array(
-        'files' => array(
-          'js' => array('example_1.js'),
-          'css' => array('example_1.css'),
-          'php' => array('example_1.php'),
-        ),
-      ),
-      '2' => array(
-        'files' => array(
-          'js' => array('example_2.js'),
-          'css' => array('example_2.css'),
-          'php' => array('example_2.php'),
-        ),
-      ),
-    ),
-  );
-
-  // Test variant detection.
-  $libraries['example_variant_missing'] = array(
-    'name' => 'Example variant missing',
-    'library path' => drupal_get_path('module', 'libraries') . '/tests/example',
-    'version' => '1',
-    'variants' => array(
-      'example_variant' => array(
-        'files' => array(
-          'js' => array('example_3.js'),
-          'css' => array('example_3.css'),
-          'php' => array('example_3.php'),
-        ),
-        'variant callback' => '_libraries_test_return_installed',
-        'variant arguments' => array(FALSE),
-      ),
-    ),
-  );
-
-  $libraries['example_variant'] = array(
-    'name' => 'Example variant',
-    'library path' => drupal_get_path('module', 'libraries') . '/tests/example',
-    'version' => '1',
-    'variants' => array(
-      'example_variant' => array(
-        'files' => array(
-          'js' => array('example_3.js'),
-          'css' => array('example_3.css'),
-          'php' => array('example_3.php'),
-        ),
-        'variant callback' => '_libraries_test_return_installed',
-        'variant arguments' => array(TRUE),
-      ),
-    ),
-  );
-
-  // Test correct behaviour with multiple versions and multiple variants.
-  $libraries['example_versions_and_variants'] = array(
-    'name' => 'Example versions and variants',
-    'library path' => drupal_get_path('module', 'libraries') . '/tests/example',
-    'version' => '2',
-    'versions' => array(
-      '1' => array(
-        'variants' => array(
-          'example_variant_1' => array(
-            'files' => array(
-              'js' => array('example_1.js'),
-              'css' => array('example_1.css'),
-              'php' => array('example_1.php'),
-            ),
-            'variant callback' => '_libraries_test_return_installed',
-            'variant arguments' => array(TRUE),
-          ),
-          'example_variant_2' => array(
-            'files' => array(
-              'js' => array('example_2.js'),
-              'css' => array('example_2.css'),
-              'php' => array('example_2.php'),
-            ),
-            'variant callback' => '_libraries_test_return_installed',
-            'variant arguments' => array(TRUE),
-          ),
-        ),
-      ),
-      '2' => array(
-        'variants' => array(
-          'example_variant_1' => array(
-            'files' => array(
-              'js' => array('example_3.js'),
-              'css' => array('example_3.css'),
-              'php' => array('example_3.php'),
-            ),
-            'variant callback' => '_libraries_test_return_installed',
-            'variant arguments' => array(TRUE),
-          ),
-          'example_variant_2' => array(
-            'files' => array(
-              'js' => array('example_4.js'),
-              'css' => array('example_4.css'),
-              'php' => array('example_4.php'),
-            ),
-            'variant callback' => '_libraries_test_return_installed',
-            'variant arguments' => array(TRUE),
-          ),
-        ),
-      ),
-    ),
-  );
-
-  // Test dependency loading.
-  // We add one file to each library to be able to verify if it was loaded with
-  // libraries_load().
-  // This library acts as a dependency for the libraries below.
-  $libraries['example_dependency'] = array(
-    'name' => 'Example dependency',
-    'library path' => drupal_get_path('module', 'libraries') . '/tests/example',
-    'version' => '1.1',
-    'files' => array('js' => array('example_1.js')),
-  );
-  $libraries['example_dependency_missing'] = array(
-    'name' => 'Example dependency missing',
-    'library path' => drupal_get_path('module', 'libraries') . '/tests/example',
-    'version' => '1',
-    'dependencies' => array('example_missing'),
-    'files' => array('js' => array('example_1.js')),
-  );
-  $libraries['example_dependency_incompatible'] = array(
-    'name' => 'Example dependency incompatible',
-    'library path' => drupal_get_path('module', 'libraries') . '/tests/example',
-    'version' => '1',
-    'dependencies' => array('example_dependency (>1.1)'),
-    'files' => array('js' => array('example_1.js')),
-  );
-  $libraries['example_dependency_compatible'] = array(
-    'name' => 'Example dependency compatible',
-    'library path' => drupal_get_path('module', 'libraries') . '/tests/example',
-    'version' => '1',
-    'dependencies' => array('example_dependency (>=1.1)'),
-    'files' => array('js' => array('example_1.js')),
-  );
-
-  // Test the applying of callbacks.
-  $libraries['example_callback'] = array(
-    'name' => 'Example callback',
-    'library path' => drupal_get_path('module', 'libraries') . '/tests/example',
-    'version' => '1',
-    'versions' => array(
-      '1' => array(
-        'variants' => array(
-          'example_variant' => array(
-            // These keys are for testing purposes only.
-            'info callback' => 'not applied',
-            'pre-detect callback' => 'not applied',
-            'post-detect callback' => 'not applied',
-            'pre-load callback' => 'not applied',
-            'post-load callback' => 'not applied',
-          ),
-        ),
-        // These keys are for testing purposes only.
-        'info callback' => 'not applied',
-        'pre-detect callback' => 'not applied',
-        'post-detect callback' => 'not applied',
-        'pre-load callback' => 'not applied',
-        'post-load callback' => 'not applied',
-      ),
-    ),
-    'variants' => array(
-      'example_variant' => array(
-        // These keys are for testing purposes only.
-        'info callback' => 'not applied',
-        'pre-detect callback' => 'not applied',
-        'post-detect callback' => 'not applied',
-        'pre-load callback' => 'not applied',
-        'post-load callback' => 'not applied',
-      ),
-    ),
-    'callbacks' => array(
-      'info' => array('_libraries_test_info_callback'),
-      'pre-detect' => array('_libraries_test_pre_detect_callback'),
-      'post-detect' => array('_libraries_test_post_detect_callback'),
-      'pre-load' => array('_libraries_test_pre_load_callback'),
-      'post-load' => array('_libraries_test_post_load_callback'),
-    ),
-    // These keys are for testing purposes only.
-    'info callback' => 'not applied',
-    'pre-detect callback' => 'not applied',
-    'post-detect callback' => 'not applied',
-    'pre-load callback' => 'not applied',
-    'post-load callback' => 'not applied',
-  );
-
-  return $libraries;
-}
-
-/**
- * Implements hook_libraries_info_file_paths()
- */
-function libraries_test_libraries_info_file_paths() {
-  return array(drupal_get_path('module', 'libraries_test') . '/example');
-}
-
-/**
- * Gets the version of an example library.
- *
- * Returns exactly the version string entered as the $version parameter. This
- * function cannot be collapsed with _libraries_test_return_installed(), because
- * of the different arguments that are passed automatically.
- */
-function _libraries_test_return_version($library, $version) {
-  return $version;
-}
-
-/**
- * Gets the version information from an arbitrary library.
- *
- * Test function for a version callback with multiple arguments. This is an
- * exact copy of libraries_get_version(), which uses a single $option argument,
- * except for the fact that it uses multiple arguments. Since we support both
- * type of version callbacks, detecting the version of a test library with this
- * function ensures that the arguments are passed correctly. This function might
- * be a useful reference for a custom version callback that uses multiple
- * parameters.
- *
- * @param $library
- *   An associative array containing all information about the library.
- * @param $file
- *   The filename to parse for the version, relative to the library path. For
- *   example: 'docs/changelog.txt'.
- * @param pattern
- *   A string containing a regular expression (PCRE) to match the library
- *   version. For example: '/@version (\d+)\.(\d+)/'.
- * @param lines
- *   (optional) The maximum number of lines to search the pattern in. Defaults
- *   to 20.
- * @param cols
- *   (optional) The maximum number of characters per line to take into account.
- *   Defaults to 200. In case of minified or compressed files, this prevents
- *   reading the entire file into memory.
- *
- * @return
- *   A string containing the version of the library.
- *
- * @see libraries_get_version()
- */
-function _libraries_test_get_version($library, $file, $pattern, $lines = 20, $cols = 200) {
-
-  $file = DRUPAL_ROOT . '/' . $library['library path'] . '/' . $file;
-  if (!file_exists($file)) {
-    return;
-  }
-  $file = fopen($file, 'r');
-  while ($lines && $line = fgets($file, $cols)) {
-    if (preg_match($pattern, $line, $version)) {
-      fclose($file);
-      return $version[1];
-    }
-    $lines--;
-  }
-  fclose($file);
-}
-
-/**
- * Detects the variant of an example library.
- *
- * Returns exactly the value of $installed, either TRUE or FALSE. This function
- * cannot be collapsed with _libraries_test_return_version(), because of the
- * different arguments that are passed automatically.
- */
-function _libraries_test_return_installed($library, $name, $installed) {
-  return $installed;
-}
-
-/**
- * Sets the 'info callback' key.
- *
- * This function is used as a test callback for the 'info' callback group.
- *
- * @see _libraries_test_callback()
- */
-function _libraries_test_info_callback(&$library, $version, $variant) {
-  _libraries_test_callback($library, $version, $variant, 'info');
-}
-
-/**
- * Sets the 'pre-detect callback' key.
- *
- * This function is used as a test callback for the 'pre-detect' callback group.
- *
- * @see _libraries_test_callback()
- */
-function _libraries_test_pre_detect_callback(&$library, $version, $variant) {
-  _libraries_test_callback($library, $version, $variant, 'pre-detect');
-}
-
-/**
- * Sets the 'post-detect callback' key.
- *
- * This function is used as a test callback for the 'post-detect callback group.
- *
- * @see _libraries_test_callback()
- */
-function _libraries_test_post_detect_callback(&$library, $version, $variant) {
-  _libraries_test_callback($library, $version, $variant, 'post-detect');
-}
-
-/**
- * Sets the 'pre-load callback' key.
- *
- * This function is used as a test callback for the 'pre-load' callback group.
- *
- * @see _libraries_test_callback()
- */
-function _libraries_test_pre_load_callback(&$library, $version, $variant) {
-  _libraries_test_callback($library, $version, $variant, 'pre-load');
-}
-
-/**
- * Sets the 'post-load callback' key.
- *
- * This function is used as a test callback for the 'post-load' callback group.
- *
- * @see _libraries_test_callback()
- */
-function _libraries_test_post_load_callback(&$library, $version, $variant) {
-  _libraries_test_callback($library, $version, $variant, 'post-load');
-}
-
-/**
- * Sets the '[group] callback' key, where [group] is prepare, detect, or load.
- *
- * This function is used as a test callback for the all callback groups.
- *
- * It sets the '[group] callback' (see above) key to 'applied ([part])' where
- * [part] is either 'top-level', 'version x.y' (where x.y is the passed-in
- * version string), 'variant example' (where example is the passed-in variant
- * name), or 'version x.y, variant example' (see above), depending on the part
- * of the library the passed-in library information belongs to.
- *
- * @param $library
- *   An array of library information, which may be version- or variant-specific.
- *   Passed by reference.
- * @param $version
- *   The version the library information passed in $library belongs to, or NULL
- *   if the passed library information is not version-specific.
- * @param $variant
- *   The variant the library information passed in $library belongs to, or NULL
- *   if the passed library information is not variant-specific.
- */
-function _libraries_test_callback(&$library, $version, $variant, $group) {
-  $string = 'applied';
-  if (isset($version) && isset($variant)) {
-    $string .= " (version $version, variant $variant)";
-  }
-  elseif (isset($version)) {
-    $string .= " (version $version)";
-  }
-  elseif (isset($variant)) {
-    $string .= " (variant $variant)";
-  }
-  else {
-    $string .= ' (top-level)';
-  }
-  $library["$group callback"] = $string;
-
-  // The following is used to test caching of library information.
-  // Only set the message for the top-level library to prevent confusing,
-  // duplicate messages.
-  if (!isset($version) && !isset($variant) && variable_get('libraries_test_cache', FALSE)) {
-    drupal_set_message("The <em>$group</em> callback group was invoked.");
-  }
-}
-
-/**
- * Implements hook_menu().
- */
-function libraries_test_menu() {
-  $base = array(
-    'page callback' => '_libraries_test_load',
-    'access callback' => TRUE,
-  );
-  $items['libraries_test/files'] = $base + array(
-    'title' => 'Test files',
-    'page arguments' => array('example_files'),
-  );
-  $items['libraries_test/integration_files'] = $base + array(
-    'title' => 'Test integration files',
-    'page arguments' => array('example_integration_files'),
-  );
-  $items['libraries_test/versions'] = $base + array(
-    'title' => 'Test version loading',
-    'page arguments' => array('example_versions'),
-  );
-  $items['libraries_test/variant'] = $base + array(
-    'title' => 'Test variant loading',
-    'page arguments' => array('example_variant', 'example_variant'),
-  );
-  $items['libraries_test/versions_and_variants'] = $base + array(
-    'title' => 'Test concurrent version and variant loading',
-    'page arguments' => array('example_versions_and_variants', 'example_variant_2'),
-  );
-  $items['libraries_test/cache'] = $base + array(
-    'title' => 'Test caching of library information',
-    'page arguments' => array('example_callback'),
-  );
-  return $items;
-}
-
-/**
- * Loads a specified library (variant) for testing.
- *
- * JavaScript and CSS files can be checked directly by SimpleTest, so we only
- * need to manually check for PHP files. We provide information about the loaded
- * JavaScript and CSS files for easier debugging. See example/README.txt for
- * more information.
- */
-function _libraries_test_load($library, $variant = NULL) {
-  libraries_load($library, $variant);
-  // JavaScript and CSS files can be checked directly by SimpleTest, so we only
-  // need to manually check for PHP files.
-  $output = '';
-
-  // For easer debugging of JS loading, a text is shown that the JavaScript will
-  // replace.
-  $output .= '<h2>JavaScript</h2>';
-  $output .= '<div class="libraries-test-javascript">';
-  $output .= 'If this text shows up, no JavaScript test file was loaded.';
-  $output .= '</div>';
-
-  // For easier debugging of CSS loading, the loaded CSS files will color the
-  // following text.
-  $output .= '<h2>CSS</h2>';
-  $output .= '<div class="libraries-test-css">';
-  $output .= 'If one of the CSS test files has been loaded, this text will be colored:';
-  $output .= '<ul>';
-  // Do not reference the actual CSS files (i.e. including '.css'), because that
-  // breaks testing.
-  $output .= '<li>example_1: red</li>';
-  $output .= '<li>example_2: green</li>';
-  $output .= '<li>example_3: orange</li>';
-  $output .= '<li>example_4: blue</li>';
-  $output .= '<li>libraries_test: purple</li>';
-  $output .= '</ul>';
-  $output .= '</div>';
-
-  $output .= '<h2>PHP</h2>';
-  $output .= '<div class="libraries-test-php">';
-  $output .= 'The following is a list of all loaded test PHP files:';
-  $output .= '<ul>';
-  $files = get_included_files();
-  foreach ($files as $file) {
-    if (strpos($file, 'libraries/test') && !strpos($file, 'libraries_test.module')) {
-      $output .= '<li>' . str_replace(DRUPAL_ROOT . '/', '', $file) . '</li>';
-    }
-  }
-  $output .= '</ul>';
-  $output .= '</div>';
-
-  return $output;
-}