hook_libraries_info() doesn't work

Question

I have a custom almost empty module where I'm tring to insert a js file using hook_libraries_info(). But when I load the home I don't see my script inserted. It works when I use a simple drupal_add_js.
What I'm doing wrong? I've seen other examples like masonry and nivo-slider and those are similar. Do I need to init somehow? I'm new at module development, so probably is something simple.

DETAILS
Libraries module is enabled:
- Libraries 7.x-2.1

The location of the library folder is this:
- sites/all/libraries/test/test.js

test.module

<?php
//drupal_add_js('sites/all/libraries/test/test.js'); when uncommented it works

/**
 * Implements hook_libraries_info().
 */
function test_libraries_info() {  // it never works
  $libraries['test'] = array(
    'name' => 'Test', 
    'vendor url' => 'http://www.example.com/', 
    'download url' => 'http://www.example.com/', 
    'files' => array(
      'js' => array(
        'test.js',
      ),
    ), 

  );
  return $libraries;
}

Answer 1

hook_libraries_info(), documented in libraries.api.php, is just a hook that informs the Libraries API module of any existing external library. Its purpose is not loading those libraries when a Drupal page is shown; for that, the module needs to call libraries_load() (defined in libraries.module) when necessary.

libraries_load_files() is the function that actually load in the page the CSS and Javascript files, respectively with drupal_add_css() and drupal_add_js().

  // Load both the JavaScript and the CSS files.
  // The parameters for drupal_add_js() and drupal_add_css() require special
  // handling.
  // @see drupal_process_attached()
  foreach (array('js', 'css') as $type) {
    if (!empty($library['files'][$type])) {
      foreach ($library['files'][$type] as $data => $options) {
        // If the value is not an array, it's a filename and passed as first
        // (and only) argument.
        if (!is_array($options)) {
          $data = $options;
          $options = array();
        }
        // In some cases, the first parameter ($data) is an array. Arrays can't
        // be passed as keys in PHP, so we have to get $data from the value
        // array.
        if (is_numeric($data)) {
          $data = $options['data'];
          unset($options['data']);
        }
        // Prepend the library path to the file name.
        $data = "$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;
        }
        call_user_func('drupal_add_' . $type, $data, $options);
        $count++;
      }
    }
  }

Answer 2

You are missing the version part which is necessary:

version arguments' => array(
      'file' => 'readme.txt',
      // Best practice: Document the actual version strings for later reference.
      // 1.x: Version 1.0 
      'pattern' => '/Version (\d+)/', 
      'lines' => 5,
    ), 

http://drupalcontrib.org/api/drupal/contributions!libraries!libraries.api.php/function/hook_libraries_info/7