Issue #3165010 by dpi, acbramley, tim.plunkett, larowlan: Using the layout...

Issue #3165010 by dpi, acbramley, tim.plunkett, larowlan: Using the layout builder discard changes button should ignore any input and skip validation

(cherry picked from commit db43eba8)

core/modules/layout_builder/src/Form/OverridesEntityForm.php

@@ -198,6 +198,8 @@ protected function actions(array $form, FormStateInterface $form_state) {
       '#value' => $this->t('Discard changes'),
       '#submit' => ['::redirectOnSubmit'],
       '#redirect' => 'discard_changes',
+      // Discard is not dependent on form input.
+      '#limit_validation_errors' => [],
     ];
     // @todo This button should be conditionally displayed, see
     //   https://www.drupal.org/node/2917777.

core/modules/layout_builder/tests/src/Functional/LayoutBuilderFormModeTest.php

+<?php
+
+namespace Drupal\Tests\layout_builder\Functional;
+
+use Drupal\Core\Entity\Entity\EntityFormDisplay;
+use Drupal\Core\Entity\Entity\EntityFormMode;
+use Drupal\entity_test\Entity\EntityTest;
+use Drupal\field\Entity\FieldConfig;
+use Drupal\field\Entity\FieldStorageConfig;
+use Drupal\layout_builder\Entity\LayoutBuilderEntityViewDisplay;
+use Drupal\Tests\BrowserTestBase;
+
+/**
+ * Tests Layout Builder forms.
+ *
+ * @group layout_builder
+ */
+class LayoutBuilderFormModeTest extends BrowserTestBase {
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $modules = [
+    'field',
+    'entity_test',
+    'layout_builder',
+  ];
+
+  /**
+   * {@inheritdoc}
+   */
+  protected $defaultTheme = 'classy';
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp(): void {
+    parent::setUp();
+
+    // Set up a field with a validation constraint.
+    $field_storage = FieldStorageConfig::create([
+      'field_name' => 'foo',
+      'entity_type' => 'entity_test',
+      'type' => 'string',
+    ]);
+    $field_storage->save();
+
+    FieldConfig::create([
+      'field_storage' => $field_storage,
+      'bundle' => 'entity_test',
+      // Expecting required value.
+      'required' => TRUE,
+    ])->save();
+
+    // Enable layout builder custom layouts.
+    LayoutBuilderEntityViewDisplay::create([
+      'targetEntityType' => 'entity_test',
+      'bundle' => 'entity_test',
+      'mode' => 'default',
+      'status' => TRUE,
+    ])
+      ->enable()
+      ->enableLayoutBuilder()
+      ->setOverridable()
+      ->save();
+
+    // Add the form mode and show the field with a constraint.
+    EntityFormMode::create([
+      'id' => 'entity_test.layout_builder',
+      'targetEntityType' => 'entity_test',
+    ])->save();
+    EntityFormDisplay::create([
+      'targetEntityType' => 'entity_test',
+      'bundle' => 'entity_test',
+      'mode' => 'layout_builder',
+      'status' => TRUE,
+    ])
+      ->setComponent('foo', [
+        'type' => 'string_textfield',
+      ])
+      ->save();
+
+    $this->drupalLogin($this->drupalCreateUser([
+      'view test entity',
+      'configure any layout',
+      'configure all entity_test entity_test layout overrides',
+    ]));
+
+    EntityTest::create()->setName($this->randomMachineName())->save();
+  }
+
+  /**
+   * Tests that the 'Discard changes' button skips validation and ignores input.
+   */
+  public function testDiscardValidation() {
+    $page = $this->getSession()->getPage();
+    $assert_session = $this->assertSession();
+
+    // When submitting the form normally, a validation error should be shown.
+    $this->drupalGet('entity_test/1/layout');
+    $assert_session->fieldExists('foo[0][value]');
+    $assert_session->elementAttributeContains('named', ['field', 'foo[0][value]'], 'required', 'required');
+    $page->pressButton('Save layout');
+    $assert_session->pageTextContains('foo field is required.');
+
+    // When Discarding changes, a validation error will not be shown.
+    // Reload the form for fresh state.
+    $this->drupalGet('entity_test/1/layout');
+    $page->pressButton('Discard changes');
+    $assert_session->pageTextNotContains('foo field is required.');
+    $assert_session->addressEquals('entity_test/1/layout/discard-changes');
+
+    // Submit the form to ensure no invalid form state retained.
+    $page->pressButton('Confirm');
+    $assert_session->pageTextContains('The changes to the layout have been discarded.');
+  }
+
+}