protected function getBootstrapSassJavascripts()
  {
    $process = new Process("gem which bootstrap-sass");
    $process->run();
    if (!$process->isSuccessful()) {
      throw new WatcherCompileException(
        "`bootstrap-sass` gem was not found\n\n" . $process->getOutput()
      );
    }

    $gemPath = trim($process->getOutput());
    $bjsRootPath = dirname(dirname($gemPath)) . "/assets/javascripts";
    $bjsPath = $bjsRootPath . "/bootstrap-sprockets.js";
    $bjs = file_get_contents($bjsPath);

    $inputs = array();
    $matches = array();
    if (preg_match_all("/\/\/= require (.*)/i", $bjs, $matches)) {
      foreach ($matches[1] as $asset) {
        $inputs[] = $bjsRootPath . "/" . $asset . ".js";
      }
    } else {
      $inputs[] = $bjsPath;
    }
    return $inputs;
  }