Issue #3350607 by mcaddz, acbramley: Add Script form broken on Drupal 10

src/Entity/Script.php

@@ -88,14 +88,14 @@ class Script extends ConfigEntityBase implements ScriptInterface, EntityWithPlug
    * {@inheritdoc}
    */
   public function getSnippet(): string {
-    return $this->snippet;
+    return $this->snippet ?? '';
   }
 
   /**
    * {@inheritdoc}
    */
   public function getPosition(): string {
-    return $this->position;
+    return $this->position ?? '';
   }
 
   /**

tests/src/Functional/ScriptManagerAdminTest.php

+<?php
+
+declare(strict_types = 1);
+
+namespace Drupal\Tests\script_manager\Functional;
+
+use Drupal\Core\Url;
+use Drupal\script_manager\Entity\Script;
+use Drupal\script_manager\Entity\ScriptInterface;
+use Drupal\Tests\BrowserTestBase;
+
+/**
+ * Test the script manager admin UI.
+ *
+ * @group script_manager
+ */
+final class ScriptManagerAdminTest extends BrowserTestBase {
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $modules = [
+    'script_manager',
+    'block',
+  ];
+
+  /**
+   * {@inheritdoc}
+   */
+  protected $defaultTheme = 'stark';
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp(): void {
+    parent::setUp();
+    $this->drupalPlaceBlock('local_actions_block');
+  }
+
+  /**
+   * Test the admin UI.
+   */
+  public function testAdminUi(): void {
+    $this->drupalLogin($this->drupalCreateUser([
+      'administer scripts',
+    ]));
+
+    $collectionUrl = Url::fromRoute('entity.script.collection');
+    $this->drupalGet($collectionUrl);
+    $assert = $this->assertSession();
+    $assert->statusCodeEquals(200);
+    $assert->pageTextContains('There are no script entities yet');
+    $assert->linkExists('Add Script');
+    $this->clickLink('Add Script');
+    $assert->statusCodeEquals(200);
+
+    $this->submitForm([
+      'label' => 'Foo',
+      'id' => 'foo',
+      'position' => ScriptInterface::POSITION_TOP,
+      'snippet' => 'bar',
+    ], 'Save');
+
+    $script = Script::load('foo');
+    $assert->addressEquals($collectionUrl->toString());
+    $assert->pageTextContains('Foo');
+    $assert->linkByHrefExists($script->toUrl('edit-form')->toString());
+    $assert->linkByHrefExists($script->toUrl('delete-form')->toString());
+
+    $this->clickLink('Edit');
+    $assert->fieldValueEquals('label', 'Foo');
+    $assert->fieldValueEquals('position', ScriptInterface::POSITION_TOP);
+    $assert->fieldValueEquals('snippet', 'bar');
+
+    $this->drupalGet($script->toUrl('delete-form'));
+    $this->submitForm([], 'Delete');
+    $assert->pageTextContains('The script Foo has been deleted.');
+    $assert->pageTextContains('There are no script entities yet');
+  }
+
+}