Symfony/css-selector added to make writing web tests easier

Drupal's WebTestBase now includes a ::cssSelect method. This method leverages the Symfony CSS-selector component which translates CSS selectors into xpath.

Previously writing web-tests required the developer to use xpath to find and select elements on the page. Xpath is quite difficult to learn and hence created a barrier to writing tests for new contributors.

Most developers are familiar with CSS selectors so by adding Symfony's CssSelector component to core, it is hoped that the barrier to writing tests has been lowered.

To use the new functionality use the cssSelect method on your web-test.

Before

$elements = $this->xpath('//div[contains(concat(" ", normalize-space(@class), " "), :field_class)]/li[@data-id=:data_id and ./h2[contains(., :text)]]', array(
  ':field_class' => 'tours',
  ':data_id' => 'tour-test-1',
   ':text' => 'The first tip',
));

After

$elements = $this->cssSelect("div.tours > li[data-id=tour-test-1] h2:contains('The first tip')");