WebUI: For cr-dialog, make Enter click the action-button, if it exists.

chrome/test/data/webui/cr_elements/cr_dialog_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('cr-dialog', function() {
   setup(function() {
     PolymerTest.clearBody();
   });
 
   test('focuses title on show', function() {
     document.body.innerHTML = `
       <dialog is="cr-dialog">
         <div class="title">title</div>
         <div class="body"><button>button</button></div>
       </dialog>`;
 
     var dialog = document.body.querySelector('dialog');
     var button = document.body.querySelector('button');
 
     assertNotEquals(dialog, document.activeElement);
     assertNotEquals(button, document.activeElement);
 
     dialog.showModal();
 
     expectEquals(dialog, document.activeElement);
     expectNotEquals(button, document.activeElement);
   });
 
+  test('enter key clicks action button', function() {
+    document.body.innerHTML = `
+      <dialog is="cr-dialog">
+        <div class="title">title</div>
+        <div class="body">
+          <button class="action-button" disabled>button</button>
+          <button id="other-button">other button</button>
+        </div>
+      </dialog>`;
+
+    var dialog = document.body.querySelector('dialog');
+    var actionButton = document.body.querySelector('.action-button');
+
+    dialog.showModal();
+
+    // MockInteractions triggers event listeners synchronously.
+    var clickedCounter = 0;
+    actionButton.addEventListener('click', function() {
+      clickedCounter += 1;
+    });
+
+    // Enter key should ignore disabled buttons.
+    MockInteractions.keyEventOn(dialog, 'keypress', 13, undefined, 'Enter');
+    assertEquals(0, clickedCounter);
+
+    // Enter key should trigger enabled buttons.
+    actionButton.disabled = false;
+    MockInteractions.keyEventOn(dialog, 'keypress', 13, undefined, 'Enter');
+    assertEquals(1, clickedCounter);
+
+    // Enter keys on other buttons should be ignored.
+    clickedCounter = 0;
+    var otherButton = document.body.querySelector('#other-button');
+    assertTrue(!!otherButton);
+    MockInteractions.keyEventOn(
+        otherButton, 'keypress', 13, undefined, 'Enter');
+    assertEquals(0, clickedCounter);
+
+    // Enter key on the action button should only fire the click handler once.
+    MockInteractions.tap(actionButton, 'keypress', 13, undefined, 'Enter');
+    assertEquals(1, clickedCounter);
+  });
+
   test('focuses [autofocus] instead of title when present', function() {
     document.body.innerHTML = `
       <dialog is="cr-dialog">
         <div class="title">title</div>
         <div class="body"><button autofocus>button</button></div>
       </dialog>`;
 
     var dialog = document.body.querySelector('dialog');
     var button = document.body.querySelector('button');
 
@@ skipping 33 matching lines @@
       }
     });
     observer.observe(bodyContainer, {attributes: true});
 
     // Height is normally set via CSS, but mixin doesn't work with innerHTML.
     bodyContainer.style.height = '1px';
     bodyContainer.scrollTop = 100;
     dialog.showModal();  // Attach the dialog for the first time here.
   });
 });