code: @Test public void shouldApplyProcessorOnlyOnResourcesWithExtensionJs() throws Exception {
    final ResourcePreProcessor decoratedProcessor=new JSMinProcessor();
    final ResourcePreProcessor processor=ExtensionsAwareProcessorDecorator.decorate(decoratedProcessor).addExtension("js");
    WroTestUtils.createInjector().inject(processor);
    final URL url=ResourcePreProcessor.class.getResource("extensionAware");
    final File testFolder=new File(url.getFile(),"test");
    final File expectedFolder=new File(url.getFile(),"expected");
    WroTestUtils.compareFromDifferentFolders(testFolder,expectedFolder,processor);
  }
  