Converted Observatory library-nav-menu element

runtime/observatory/tests/observatory_ui/nav/library-menu/element_test.dart

+// Copyright (c) 2016, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+import 'dart:html';
+import 'package:unittest/unittest.dart';
+import 'package:observatory/mocks.dart';
+import 'package:observatory/src/elements/nav/library_menu.dart';
+
+main(){
+  NavLibraryMenuElement.tag.ensureRegistration();
+
+  final IsolateRefMock i_ref = const IsolateRefMock(id: 'i-id', name: 'i-name');
+  final LibraryRefMock l_ref = const LibraryRefMock(id: 'l-id', name: 'l-name');
+  test('instantiation', () {
+    final NavLibraryMenuElement e = new NavLibraryMenuElement(i_ref, l_ref);
+    expect(e, isNotNull, reason: 'element correctly created');
+    expect(e.isolate, equals(i_ref));
+    expect(e.library, equals(l_ref));
+  });
+  test('elements created after attachment', () async {
+    final NavLibraryMenuElement e = new NavLibraryMenuElement(i_ref, l_ref);
+    document.body.append(e);
+    await e.onRendered.first;
+    expect(e.shadowRoot.children.length, isNonZero, reason: 'has elements');
+    e.remove();
+    await e.onRendered.first;
+    expect(e.shadowRoot.children.length, isZero, reason: 'is empty');
+  });
+}