Test case

Closes #3470867

tests/modules/csp_test/src/Controller/TestPageController.php

@@ -116,4 +116,17 @@ class TestPageController extends ControllerBase {
     ];
   }
 
+  /**
+   * Returns a test page that will have its attachments altered.
+   *
+   * @return array<string, mixed>
+   *   A render array.
+   */
+  public function testPageAttachmentsNonce(): array {
+    return [
+      '#title' => 'Test page',
+      '#markup' => 'Test page text.',
+    ];
+  }
+
 }