--- /dev/null
+<?php
+
+namespace Drupal\views_test_data\Form;
+
+use Drupal\Core\Form\FormInterface;
+use Drupal\Core\Form\FormStateInterface;
+
+/**
+ * Implements a test form that has a validation error.
+ */
+class ViewsTestDataErrorForm implements FormInterface {
+
+ /**
+ * {@inheritdoc}
+ */
+ public function getFormId() {
+ return 'views_test_data_error_form';
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function buildForm(array $form, FormStateInterface $form_state) {
+ $form['text'] = [
+ '#type' => 'textfield',
+ ];
+ $form['submit'] = [
+ '#type' => 'submit',
+ '#value' => t('Submit'),
+ ];
+
+ return $form;
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function validateForm(array &$form, FormStateInterface $form_state) {
+ $form_state->setErrorByName('text', t('Form validation error'));
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function submitForm(array &$form, FormStateInterface $form_state) {
+ }
+
+}