MiniAsset\Factory::filterRegistry PHP Method

    public function filterRegistry()
    {
        $filters = [];
        foreach ($this->config->allFilters() as $name) {
            $filters[$name] = $this->buildFilter($name, $this->config->filterConfig($name));
        }
        return new FilterRegistry($filters);
    }

 /**
  * @expectedException RuntimeException
  * @expectedExceptionMessage Cannot load filter "Derp"
  */
 public function testFilterRegistryMissingFilter()
 {
     $this->config->filters('js', ['Derp']);
     $this->config->filterConfig('Derp', ['path' => '/test']);
     $factory = new Factory($this->config);
     $factory->filterRegistry();
 }