[MD Bookmarks] Add keyboard navigation to sidebar.

chrome/test/data/webui/md_bookmarks/folder_node_test.js

 // Copyright 2016 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.
 
 suite('<bookmarks-folder-node>', function() {
   var rootNode;
   var store;
 
+  function getFolderNode(id) {
+    return findFolderNode(rootNode, id);
+  }
+
   setup(function() {
     store = new bookmarks.TestStore({
       nodes: testTree(
           createFolder(
               '1',
               [
                 createFolder(
                     '2',
                     [
                       createFolder('3', []),
                       createFolder('4', []),
                     ]),
                 createItem('5'),
               ]),
           createFolder('7', [])),
+      selectedFolder: '1',
     });
     bookmarks.Store.instance_ = store;
 
     rootNode = document.createElement('bookmarks-folder-node');
     rootNode.itemId = '0';
     rootNode.depth = -1;
     replaceBody(rootNode);
     Polymer.dom.flush();
   });
 
@@ skipping 34 matching lines @@
     });
     Array.prototype.forEach.call(secondGen, function(f) {
       assertEquals(2, f.depth);
       assertEquals('2', f.style.getPropertyValue('--node-depth'));
     });
   });
 
   test('doesn\'t highlight selected folder while searching', function() {
     var rootFolders = rootNode.root.querySelectorAll('bookmarks-folder-node');
 
-    store.data.selectedFolder = '1';
-    store.notifyObservers();
-
     assertEquals('1', rootFolders['0'].itemId);
     assertTrue(rootFolders['0'].isSelectedFolder_);
 
     store.data.search = {
       term: 'test',
       inProgress: false,
       results: ['3'],
     };
     store.notifyObservers();
 
     assertFalse(rootFolders['0'].isSelectedFolder_);
   });
+
+  test('last visible descendant', function() {
+    assertEquals('7', rootNode.getLastVisibleDescendant_().itemId);
+    assertEquals('4', getFolderNode('1').getLastVisibleDescendant_().itemId);
+
+    store.data.closedFolders = new Set('2');
+    store.notifyObservers();
+
+    assertEquals('2', getFolderNode('1').getLastVisibleDescendant_().itemId);
+  });
+
+  test('get node parent', function() {
+    assertEquals(getFolderNode('0'), getFolderNode('1').getParentFolderNode_());
+    assertEquals(getFolderNode('2'), getFolderNode('4').getParentFolderNode_());
+    assertEquals(null, getFolderNode('0').getParentFolderNode_());
+  });
+
+  test('next/previous folder nodes', function() {
+    function getNextChild(parentId, targetId, reverse) {
+      return getFolderNode(parentId).getNextChild_(
+          reverse, getFolderNode(targetId));
+    }
+
+    // Forwards.
+    assertEquals('4', getNextChild('2', '3', false).itemId);
+    assertEquals(null, getNextChild('2', '4', false));
+
+    // Backwards.
+    assertEquals(null, getNextChild('1', '2', true));
+    assertEquals('3', getNextChild('2', '4', true).itemId);
+    assertEquals('4', getNextChild('0', '7', true).itemId);
+
+    // Skips closed folders.
+    store.data.closedFolders = new Set('2');
+    store.notifyObservers();
+
+    assertEquals(null, getNextChild('1', '2', false));
+    assertEquals('2', getNextChild('0', '7', true).itemId);
+  });
 });