Merge branch 'main' into avm99963-monorail

Merged commit cd4b3b336f1f14afa02990fdc2eec5d9467a827e

GitOrigin-RevId: e67bbf185d5538e1472bb42e0abb2a141f88bac1
diff --git a/static_src/elements/issue-detail/mr-issue-page/mr-migrated-banner.test.js b/static_src/elements/issue-detail/mr-issue-page/mr-migrated-banner.test.js
new file mode 100644
index 0000000..4cceb2b
--- /dev/null
+++ b/static_src/elements/issue-detail/mr-issue-page/mr-migrated-banner.test.js
@@ -0,0 +1,43 @@
+// Copyright 2022 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+import {assert} from 'chai';
+import {MrMigratedBanner} from './mr-migrated-banner.js';
+
+let element;
+
+describe('mr-migrated-banner', () => {
+  beforeEach(() => {
+    element = document.createElement('mr-migrated-banner');
+    document.body.appendChild(element);
+  });
+
+  afterEach(() => {
+    document.body.removeChild(element);
+  });
+
+  it('initializes', () => {
+    assert.instanceOf(element, MrMigratedBanner);
+  });
+
+  it('hides element by default', async () => {
+    await element.updateComplete;
+
+    assert.isTrue(element.hasAttribute('hidden'));
+  });
+
+  it('hides element when migratedId is empty', async () => {
+    element.migratedId = '';
+    await element.updateComplete;
+
+    assert.isTrue(element.hasAttribute('hidden'));
+  });
+
+  it('shows element when migratedId is set', async () => {
+    element.migratedId = '1234';
+    await element.updateComplete;
+
+    assert.isFalse(element.hasAttribute('hidden'));
+  });
+});