/**
  * Tests the ::register() method.
  *
  * @covers ::register()
  * @covers ::load()
  * @covers ::registerDrupalPaths()
  * @covers ::registerPsr()
  */
 public function test_register()
 {
     $loader = m::mock('\\Composer\\Autoload\\ClassLoader');
     $loader->shouldReceive('add')->once();
     $loader->shouldReceive('addPsr4')->once();
     $loader->shouldReceive('getPrefixes')->once()->andReturn(['' => 'DRUPAL_ROOT/includes']);
     $loader->shouldReceive('getPrefixesPsr4')->once()->andReturn(['Drupal\\Composer\\ClassLoader\\' => '../src/', 'Drupal\\Composer\\ClassLoader\\Tests\\' => 'src/', '' => 'DRUPAL_ROOT/includes']);
     $autoloader = new AutoloaderBootstrap($loader, 'data/docroot/sites/all/modules/testmodule/composer.json');
     $autoloader->register();
     $this->assertTrue($autoloader->checkLoadedAutoloader());
     // Make sure that calling to register a second time does not fail.
     $autoloader->register();
     $this->assertTrue($autoloader->checkLoadedAutoloader());
 }
<?php

use Drupal\Composer\ClassLoader\AutoloaderBootstrap;
// Load Composer's autoloader.
$loader = (require __DIR__ . '/../../autoload.php');
$autoloader_init = new AutoloaderBootstrap($loader);
$autoloader_init->register();