ElementsFieldsetTest.php

<?php

declare (strict_types=1);
namespace Drupal\Tests\system\Kernel\Form;

use Drupal\Core\Form\FormInterface;
use Drupal\Core\Form\FormState;
use Drupal\Core\Form\FormStateInterface;
use Drupal\KernelTests\KernelTestBase;

/**
 * Tests fieldset element rendering and description placement.
 *
 * @group Form
 */
class ElementsFieldsetTest extends KernelTestBase implements FormInterface {
    
    /**
     * {@inheritdoc}
     */
    protected static $modules = [
        'system',
    ];
    
    /**
     * {@inheritdoc}
     */
    public function getFormId() {
        return 'form_test_fieldset_element';
    }
    
    /**
     * {@inheritdoc}
     */
    public function buildForm(array $form, FormStateInterface $form_state) {
        $form['fieldset_default'] = [
            '#type' => 'fieldset',
            '#title' => 'Fieldset title for default description display',
            '#description' => 'Fieldset description for default description display.',
        ];
        $form['meta_default'] = [
            '#type' => 'container',
            '#title' => 'Group element',
            '#group' => 'fieldset_default',
        ];
        $form['meta_default']['element'] = [
            '#type' => 'textfield',
            '#title' => 'Nested text field inside meta_default element',
        ];
        $form['fieldset_before'] = [
            '#type' => 'fieldset',
            '#title' => 'Fieldset title for description displayed before element',
            '#description' => 'Fieldset description for description displayed before element.',
            '#description_display' => 'before',
        ];
        $form['meta_before'] = [
            '#type' => 'container',
            '#title' => 'Group element',
            '#group' => 'fieldset_before',
        ];
        $form['meta_before']['element'] = [
            '#type' => 'textfield',
            '#title' => 'Nested text field inside meta_before element',
        ];
        $form['fieldset_after'] = [
            '#type' => 'fieldset',
            '#title' => 'Fieldset title for description displayed after element',
            '#description' => 'Fieldset description for description displayed after element.',
            '#description_display' => 'after',
        ];
        $form['meta_after'] = [
            '#type' => 'container',
            '#title' => 'Group element',
            '#group' => 'fieldset_after',
        ];
        $form['meta_after']['element'] = [
            '#type' => 'textfield',
            '#title' => 'Nested text field inside meta_after element',
        ];
        $form['fieldset_invisible'] = [
            '#type' => 'fieldset',
            '#title' => 'Fieldset title for description displayed as visually hidden element',
            '#description' => 'Fieldset description for description displayed as visually hidden element.',
            '#description_display' => 'invisible',
        ];
        $form['meta_invisible'] = [
            '#type' => 'container',
            '#title' => 'Group element',
            '#group' => 'fieldset_invisible',
        ];
        $form['meta_invisible']['element'] = [
            '#type' => 'textfield',
            '#title' => 'Nested text field inside meta_invisible element',
        ];
        return $form;
    }
    
    /**
     * {@inheritdoc}
     */
    public function submitForm(array &$form, FormStateInterface $form_state) {
    }
    
    /**
     * {@inheritdoc}
     */
    public function validateForm(array &$form, FormStateInterface $form_state) {
    }
    
    /**
     * Tests different display options for fieldset element descriptions.
     */
    public function testFieldsetDescriptions() : void {
        $form_state = new FormState();
        $form = \Drupal::formBuilder()->getForm($this);
        $this->render($form);
        // Check #description placement with #description_display not set. By
        // default, the #description should appear after any fieldset elements.
        $field_id = 'edit-fieldset-default';
        $description_id = $field_id . '--description';
        $elements = $this->xpath('//fieldset[@id="' . $field_id . '" and @aria-describedby="' . $description_id . '"]//div[@id="edit-meta-default"]/following-sibling::div[@id="' . $description_id . '"]');
        $this->assertCount(1, $elements);
        // Check #description placement with #description_display set to 'before'.
        $field_id = 'edit-fieldset-before';
        $description_id = $field_id . '--description';
        $elements = $this->xpath('//fieldset[@id="' . $field_id . '" and @aria-describedby="' . $description_id . '"]//div[@id="edit-meta-before"]/preceding-sibling::div[@id="' . $description_id . '"]');
        $this->assertCount(1, $elements);
        // Check #description placement with #description_display set to 'after'.
        $field_id = 'edit-fieldset-after';
        $description_id = $field_id . '--description';
        $elements = $this->xpath('//fieldset[@id="' . $field_id . '" and @aria-describedby="' . $description_id . '"]//div[@id="edit-meta-after"]/following-sibling::div[@id="' . $description_id . '"]');
        $this->assertCount(1, $elements);
        // Check if the 'visually-hidden' class is set on the fieldset description
        // with #description_display set to 'invisible'. Also check that the
        // description is placed after the form element.
        $field_id = 'edit-fieldset-invisible';
        $description_id = $field_id . '--description';
        $elements = $this->xpath('//fieldset[@id="' . $field_id . '" and @aria-describedby="' . $description_id . '"]//div[@id="edit-meta-invisible"]/following-sibling::div[contains(@class, "visually-hidden")]');
        $this->assertCount(1, $elements);
        \Drupal::formBuilder()->submitForm($this, $form_state);
        $errors = $form_state->getErrors();
        $this->assertEmpty($errors);
    }

}