FormTestRequiredAttributeForm.php

<?php

namespace Drupal\form_test\Form;

use Drupal\Core\Form\FormBase;
use Drupal\Core\Form\FormStateInterface;

/**
 * Builds a form to test the required attribute.
 *
 * @internal
 */
class FormTestRequiredAttributeForm extends FormBase {
    
    /**
     * {@inheritdoc}
     */
    public function getFormId() {
        return 'form_test_required_attribute';
    }
    
    /**
     * {@inheritdoc}
     */
    public function buildForm(array $form, FormStateInterface $form_state) {
        foreach ([
            'textfield',
            'textarea',
            'password',
        ] as $type) {
            $form[$type] = [
                '#type' => $type,
                '#required' => TRUE,
                '#title' => $type,
            ];
        }
        $form['submit'] = [
            '#type' => 'submit',
            '#value' => 'Submit',
        ];
        return $form;
    }
    
    /**
     * {@inheritdoc}
     */
    public function submitForm(array &$form, FormStateInterface $form_state) {
    }

}