1 files changed, 12 insertions, 1 deletions
diff --git a/web_src/js/features/common-button.test.ts b/web_src/js/features/common-button.test.ts
index f41bafbc79..4ae1f74897 100644
--- a/web_src/js/features/common-button.test.ts
+++ b/web_src/js/features/common-button.test.ts
@@ -1,12 +1,23 @@
-import {assignElementProperty} from './common-button.ts';
+import {assignElementProperty, type ElementWithAssignableProperties} from './common-button.ts';
 
 test('assignElementProperty', () => {
   const elForm = document.createElement('form');
   assignElementProperty(elForm, 'action', '/test-link');
   expect(elForm.action).contains('/test-link'); // the DOM always returns absolute URL
+  expect(elForm.getAttribute('action')).eq('/test-link');
   assignElementProperty(elForm, 'text-content', 'dummy');
   expect(elForm.textContent).toBe('dummy');
 
+  // mock a form with its property "action" overwritten by an input element
+  const elFormWithAction = new class implements ElementWithAssignableProperties {
+    action = document.createElement('input'); // now "form.action" is not string, but an input element
+    _attrs: Record<string, string> = {};
+    setAttribute(name: string, value: string) { this._attrs[name] = value }
+    getAttribute(name: string): string | null { return this._attrs[name] }
+  }();
+  assignElementProperty(elFormWithAction, 'action', '/bar');
+  expect(elFormWithAction.getAttribute('action')).eq('/bar');
+
   const elInput = document.createElement('input');
   expect(elInput.readOnly).toBe(false);
   assignElementProperty(elInput, 'read-only', 'true');