CssOptimizer example

  protected function setUp(): void {
    parent::setUp();
    $this->fileUrlGenerator = $this->createMock(FileUrlGeneratorInterface::class);
    $this->fileUrlGenerator->expects($this->any())
      ->method('generateString')
      ->with($this->isType('string'))
      ->willReturnCallback(function D$uri) {
        return 'generated-relative-url:' . $uri;
      });
    $this->optimizer = new CssOptimizer($this->fileUrlGenerator);
  }

  /** * Provides data for the CSS asset optimizing test. */
  public function providerTestOptimize() {
    $path = 'core/tests/Drupal/Tests/Core/Asset/css_test_files/';
    $absolute_path = dirname(__FILE__) . '/css_test_files/';
    return [
      // File. Tests:       // - Stripped comments and white-space.