From ee9905d997dcae285dd3524ab1ebb4fd028aac17 Mon Sep 17 00:00:00 2001
From: Philipp Schneider <philosr@amazon.de>
Date: Thu, 5 Mar 2026 12:28:41 +0100
Subject: [PATCH 1/2] add warning in attribute-editor

---
 src/attribute-editor/internal.tsx | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/src/attribute-editor/internal.tsx b/src/attribute-editor/internal.tsx
index 7f9acd1006..048393b1fc 100644
--- a/src/attribute-editor/internal.tsx
+++ b/src/attribute-editor/internal.tsx
@@ -3,7 +3,7 @@
 import React, { useImperativeHandle, useRef, useState } from 'react';
 import clsx from 'clsx';
 
-import { useMergeRefs, useUniqueId } from '@cloudscape-design/component-toolkit/internal';
+import { useMergeRefs, useUniqueId, warnOnce } from '@cloudscape-design/component-toolkit/internal';
 
 import { ButtonProps } from '../button/interfaces';
 import { InternalButton } from '../button/internal';
@@ -92,6 +92,16 @@ const InternalAttributeEditor = React.forwardRef(
       // eslint-disable-next-line react-hooks/exhaustive-deps
     }, [items, i18nStrings?.itemRemovedAriaLive]);
 
+    for (const def of definition) {
+      if (!def.label) {
+        warnOnce(
+          'AttributeEditor',
+          'A `label` should be provided for each field definition. It is used as `aria-label` for accessibility.'
+        );
+        break;
+      }
+    }
+
     if (!gridLayout) {
       gridLayout = gridDefaults[definition.length];
       if (!gridLayout) {

From 93e44b69ebe6a49ae4ce73412a8cf633bdb24495 Mon Sep 17 00:00:00 2001
From: Philipp Schneider <philosr@amazon.de>
Date: Thu, 5 Mar 2026 12:40:16 +0100
Subject: [PATCH 2/2] added tesst

---
 .../__tests__/warnings.test.tsx               | 53 +++++++++++++++++++
 src/attribute-editor/internal.tsx             |  2 +-
 2 files changed, 54 insertions(+), 1 deletion(-)
 create mode 100644 src/attribute-editor/__tests__/warnings.test.tsx

diff --git a/src/attribute-editor/__tests__/warnings.test.tsx b/src/attribute-editor/__tests__/warnings.test.tsx
new file mode 100644
index 0000000000..0ad4b44e71
--- /dev/null
+++ b/src/attribute-editor/__tests__/warnings.test.tsx
@@ -0,0 +1,53 @@
+// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+// SPDX-License-Identifier: Apache-2.0
+import React from 'react';
+import { render } from '@testing-library/react';
+
+import AttributeEditor from '../../../lib/components/attribute-editor';
+
+jest.mock('@cloudscape-design/component-toolkit', () => ({
+  ...jest.requireActual('@cloudscape-design/component-toolkit'),
+  useContainerQuery: jest.fn().mockImplementation(() => ['m', () => {}]),
+}));
+
+let consoleWarnSpy: jest.SpyInstance;
+beforeEach(() => {
+  consoleWarnSpy = jest.spyOn(console, 'warn').mockImplementation();
+});
+afterEach(() => {
+  consoleWarnSpy?.mockRestore();
+});
+
+/**
+ * This test suite is in a separate file, because it needs a clean messageCache (inside `warnOnce()`).
+ * Otherwise, warnings would not appear at the expected time in the test, because they have been issued before.
+ */
+describe('AttributeEditor component', () => {
+  test('warns when a definition has no label', () => {
+    render(
+      <AttributeEditor
+        addButtonText="Add"
+        removeButtonText="Remove"
+        definition={[{ label: 'Key label', control: () => 'key' }]}
+        items={[{}]}
+        gridLayout={[{ rows: [[1]] }]}
+      />
+    );
+    expect(console.warn).not.toHaveBeenCalled();
+
+    render(
+      <AttributeEditor
+        addButtonText="Add"
+        removeButtonText="Remove"
+        definition={[{ label: 'Key label', control: () => 'key' }, { control: () => 'value' }]}
+        items={[{}]}
+        gridLayout={[{ rows: [[1, 1]] }]}
+      />
+    );
+
+    expect(console.warn).toHaveBeenCalledTimes(1);
+    expect(console.warn).toHaveBeenCalledWith(
+      '[AwsUi] [AttributeEditor] A `label` should be provided for each field definition. It is used as `aria-label` for accessibility.'
+    );
+  });
+});
diff --git a/src/attribute-editor/internal.tsx b/src/attribute-editor/internal.tsx
index 048393b1fc..24f3229736 100644
--- a/src/attribute-editor/internal.tsx
+++ b/src/attribute-editor/internal.tsx
@@ -93,7 +93,7 @@ const InternalAttributeEditor = React.forwardRef(
     }, [items, i18nStrings?.itemRemovedAriaLive]);
 
     for (const def of definition) {
-      if (!def.label) {
+      if (def && !def.label) {
         warnOnce(
           'AttributeEditor',
           'A `label` should be provided for each field definition. It is used as `aria-label` for accessibility.'