MD Bookmarks: Add a confirmation dialog before opening many tabs

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

 // Copyright 2017 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-command-manager>', function() {
   var commandManager;
   var store;
   var lastCommand;
   var lastCommandIds;
 
   suiteSetup(function() {
     // Overwrite bookmarkManagerPrivate APIs which will crash if called with
     // fake data.
     chrome.bookmarkManagerPrivate.copy = function() {};
     chrome.bookmarkManagerPrivate.removeTrees = function() {};
   });
 
   setup(function() {
+    var bulkChildren = [];
+    for (var i = 1; i <= 20; i++) {
+      var id = '3' + i;
+      bulkChildren.push(createItem(id, {url: `http://${id}/`}));
+    }
+
     store = new bookmarks.TestStore({
       nodes: testTree(
           createFolder(
               '1',
               [
                 createFolder(
                     '11',
                     [
                       createItem('111', {url: 'http://111/'}),
                     ]),
                 createFolder(
                     '12',
                     [
                       createItem('121', {url: 'http://121/'}),
                       createFolder(
                           '122',
                           [
                             createItem('1221'),
                           ]),
                     ]),
                 createItem('13', {url: 'http://13/'}),
               ]),
           createFolder(
               '2',
               [
                 createFolder('21', []),
-              ]))
+              ]),
+          createFolder('3', bulkChildren)),
     });
     store.replaceSingleton();
 
     commandManager = new TestCommandManager();
     replaceBody(commandManager);
     document.body.appendChild(
         document.createElement('bookmarks-toast-manager'));
 
     Polymer.dom.flush();
   });
@@ skipping 118 matching lines @@
   test('shift-enter does not trigger enter commands', function() {
     // Enter by itself performs an edit (Mac) or open (non-Mac). Ensure that
     // shift-enter doesn't trigger those commands.
     store.data.selection.items = new Set(['13']);
     store.notifyObservers();
 
     MockInteractions.pressAndReleaseKeyOn(document.body, 13, 'shift', 'Enter');
     commandManager.assertLastCommand(Command.OPEN_NEW_WINDOW);
   });
 
+  test('opening many items causes a confirmation dialog', function() {
+    var lastCreate = null;
+    chrome.windows.create = function(createConfig) {
+      lastCreate = createConfig;
+    };
+
+    var items = new Set(['3']);
+    assertTrue(commandManager.canExecute(Command.OPEN_NEW_WINDOW, items));
+
+    commandManager.handle(Command.OPEN_NEW_WINDOW, items);
+    // No window should be created right away.
+    assertEquals(null, lastCreate);
+
+    var dialog = commandManager.$.openDialog.getIfExists();
+    assertTrue(dialog.open);
+
+    // Pressing 'cancel' should not open the window.
+    MockInteractions.tap(dialog.querySelector('.cancel-button'));
+    assertFalse(dialog.open);
+    assertEquals(null, lastCreate);
+
+    commandManager.handle(Command.OPEN_NEW_WINDOW, items);
+    assertTrue(dialog.open);
+
+    // Pressing 'yes' will open all the URLs.
+    MockInteractions.tap(dialog.querySelector('.action-button'));
+    assertFalse(dialog.open);
+    assertEquals(20, lastCreate.url.length);
+  });
+
   test('cannot execute "Open in New Tab" on folders with no items', function() {
     var items = new Set(['2']);
     assertFalse(commandManager.canExecute(Command.OPEN_NEW_TAB, items));
 
     store.data.selection.items = items;
 
     commandManager.openCommandMenuAtPosition(0, 0);
     var commandItem = {};
     commandManager.root.querySelectorAll('.dropdown-item').forEach(element => {
       commandItem[element.getAttribute('command')] = element;
@@ skipping 112 matching lines @@
     assertOpenedTabs(['http://111/', 'http://12/']);
   });
 
   test('control-double click opens full selection', function() {
     customClick(items[0]);
     simulateDoubleClick(items[2], {ctrlKey: true});
 
     assertOpenedTabs(['http://111/', 'http://13/']);
   });
 });