Add an accessibility audit test for WebUI pages

chrome/test/data/webui/a11y_audit_browsertest.js

+// Copyright (c) 2012 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.
+
+function WebUIA11yAuditBrowserTest() {}
+
+WebUIA11yAuditBrowserTest.prototype = {
+  __proto__: testing.Test.prototype,
+
+  browsePreload: 'chrome://terms',
+
+  runA11yChecks: true,
+  a11yIssuesAreErrors: true,
+
+  expectedA11yWarnings: null,

[dmazzoni, 2012/12/14 18:45:41]

It should be fine to use A11y here, for variables local to this file - maybe
define it once at the top.

[aboxhall, 2012/12/14 23:26:44]

SGTM.

+  expectedA11yErrors: null,
+
+  tearDown: function() {
+    if (this.expectedA11yErrors != null)
+      expectEquals(this.expectedA11yErrors, getA11yErrors().length);
+    if (this.expectedA11yWarnings != null)
+      assertEquals(this.expectedA11yWarnings, getA11yWarnings().length);
+    testing.Test.prototype.tearDown.call(this);
+  }
+};
+
+function addAuditFailures() {
+  // Contrast ratio
+  var style = document.createElement('style');
+  style.innerText = 'p { color: #ffffff }';
+  document.head.appendChild(style);
+
+  // Bad ARIA role
+  var div = document.createElement('div');
+  div.setAttribute('role', 'not-a-role');
+  document.body.appendChild(div);
+
+  // Unlabelled control
+  var input = document.createElement('input');
+  input.type = 'text';
+  document.body.appendChild(input);
+}
+
+function mockAudit() {

[dmazzoni, 2012/12/14 18:45:41]

How about createMockAudit?

[aboxhall, 2012/12/14 23:26:44]

Done.

+  function StubAudit() {};
+  StubAudit.prototype.run = function() {};
+  return mock(StubAudit);
+}
+
+function expectAuditWillNotRun() {
+  var audit = mockAudit();
+  audit.expects(never()).run();
+  axs.Audit = audit.proxy();
+}
+
+function expectAuditWillRun(times) {
+  var audit = mockAudit();
+  var realAudit = axs.Audit;
+  var expectedInvocation = audit.expects(exactly(times)).run();
+  var willArgs = [];
+  for (var i = 0; i < times; i++)
+    willArgs.push(callFunction(realAudit.run));
+  ExpectedInvocation.prototype.will.apply(expectedInvocation, willArgs);
+  axs.Audit = audit.proxy();
+}
+
+TEST_F('WebUIA11yAuditBrowserTest', 'testWithAuditFailures_shouldFail',
+       function() {
+  expectAuditWillRun(1);
+  addAuditFailures();
+});
+
+TEST_F('WebUIA11yAuditBrowserTest',
+       'testWithAuditFailures_a11yChecksDisabled',
+       function() {
+  expectAuditWillNotRun();
+  disableA11yChecks();
+  addAuditFailures();
+});
+
+function WebUIA11yAuditBrowserTest_TestsDisabledInFixture() {}
+
+WebUIA11yAuditBrowserTest_TestsDisabledInFixture.prototype = {
+  __proto__: WebUIA11yAuditBrowserTest.prototype,
+
+  runA11yChecks: false,
+  a11yIssuesAreErrors: true,
+};
+
+TEST_F('WebUIA11yAuditBrowserTest_TestsDisabledInFixture',
+       'testWithAuditFailures_shouldFail',
+       function() {
+  expectAuditWillRun(1);
+  enableA11yChecks();
+  addAuditFailures();
+});
+
+TEST_F('WebUIA11yAuditBrowserTest_TestsDisabledInFixture',
+       'testWithAuditFailures_a11yChecksNotEnabled',
+       function() {
+  expectAuditWillNotRun();
+  addAuditFailures();
+});
+
+TEST_F('WebUIA11yAuditBrowserTest_TestsDisabledInFixture',
+       'testRunningAuditManually_noErrors',
+       function() {
+  expectAuditWillRun(1);
+  expectAccessibilityOk();
+});
+
+TEST_F('WebUIA11yAuditBrowserTest_TestsDisabledInFixture',
+       'testRunningAuditManually_withErrors_shouldFail',
+       function() {
+  expectAuditWillRun(1);
+  addAuditFailures();
+  expectAccessibilityOk();
+});
+
+TEST_F('WebUIA11yAuditBrowserTest_TestsDisabledInFixture',
+       'testRunningAuditManuallySeveralTimes', function() {
+  expectAuditWillRun(2);
+  expectAccessibilityOk();
+  expectAccessibilityOk();
+});
+
+function WebUIA11yAuditBrowserTest_IssuesAreWarnings() {}
+
+WebUIA11yAuditBrowserTest_IssuesAreWarnings.prototype = {
+  __proto__: WebUIA11yAuditBrowserTest.prototype,
+
+  a11yIssuesAreErrors: false,
+};
+
+TEST_F('WebUIA11yAuditBrowserTest_IssuesAreWarnings',
+       'testWithAuditFailures',
+        function() {
+  expectAuditWillRun(1);
+  this.expectedA11yWarnings = 1;
+  this.expectedA11yErrors = 2;
+  enableA11yChecks();
+  addAuditFailures();
+});
+