EmptyStringParser example

        $this->translator = new Translator();

        if ($html) {
            $this->translator->registerExtension(new HtmlExtension($this->translator));
            $this->cache = &self::$htmlCache;
        } else {
            $this->cache = &self::$xmlCache;
        }

        $this->translator
            ->registerParserShortcut(new EmptyStringParser())
            ->registerParserShortcut(new ElementParser())
            ->registerParserShortcut(new ClassParser())
            ->registerParserShortcut(new HashParser())
        ;
    }

    /** * Translates a CSS expression to its XPath equivalent. * * Optionally, a prefix can be added to the resulting XPath * expression with the $prefix parameter. */

use PHPUnit\Framework\TestCase;
use Symfony\Component\CssSelector\Node\SelectorNode;
use Symfony\Component\CssSelector\Parser\Shortcut\EmptyStringParser;

/** * @author Jean-François Simon <jeanfrancois.simon@sensiolabs.com> */
class EmptyStringParserTest extends TestCase
{
    public function testParse()
    {
        $parser = new EmptyStringParser();
        $selectors = $parser->parse('');
        $this->assertCount(1, $selectors);

        /** @var SelectorNode $selector */
        $selector = $selectors[0];
        $this->assertEquals('Element[*]', (string) $selector->getTree());

        $selectors = $parser->parse('this will produce an empty array');
        $this->assertCount(0, $selectors);
    }
}