Enable accessibility testing for the bookmark browser test.

chrome/test/base/in_process_browser_test.cc

 // 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.
 
 #include "chrome/test/base/in_process_browser_test.h"
 
 #include "base/auto_reset.h"
 #include "base/basictypes.h"
 #include "base/bind.h"
 #include "base/command_line.h"
@@ skipping 94 matching lines @@
   BrowserList::RemoveObserver(this);
 }
 
 void SingleDesktopTestObserver::OnBrowserAdded(Browser* browser) {
   CHECK(CalledOnValidThread());
   CHECK_EQ(browser->host_desktop_type(), allowed_desktop_);
 }
 
 }  // namespace
 
+// Library used for testing accessibility.
+const char kAXSTesting[] = "third_party/accessibility-audit/axs_testing.js";
+// JavaScript snippet to configure and run the accessibility audit.
+const char kAccessibilityTestString[] =
+    "var config = new axs.AuditConfiguration();"
+    "/* Disable warning about rules that cannot be checked. */"
+    "config.showUnsupportedRulesWarning = false;"
+    "config.auditRulesToIgnore = ["
+    "  /*"
+    "   * The 'elements with meaningful background image' accessibility"
+    "   * audit (AX_IMAGE_01) does not apply, since Chrome doesn't"
+    "   * disable background images in high-contrast mode like some"
+    "   * browsers do."
+    "   */"
+    "  'elementsWithMeaningfulBackgroundImage',"
+    "  /*"
+    "   * Most WebUI pages are inside an IFrame, so the 'web page should"
+    "   * have a title that describes topic or purpose' test (AX_TITLE_01)"
+    "   * generally does not apply."
+    "   */"
+    "  'pageWithoutTitle',"
+    "  /*"
+    "   * Enable when crbug.com/267035 is fixed."
+    "   * Until then it's just noise."
+    "   */"
+    "  'lowContrastElements'];"
+    "var result = axs.Audit.run(config);"
+    "for (var i = 0; i < result.length; ++i) {"
+    "  if (result[i].result == axs.constants.AuditResult.FAIL)"
+    "    domAutomationController.send(axs.Audit.createReport(result));"

[Jay Civelli, 2015/02/07 01:11:12]

Don't you need to return in that case?

[hcarmona, 2015/02/07 02:22:12]

Yes, now I'm wondering why this didn't fail on my machine when I ran it... Maybe
the messages are appended? Either way, this needs to return here. Done

+    "}"
+    "domAutomationController.send('');";
+
 InProcessBrowserTest::InProcessBrowserTest()
     : browser_(NULL),
       exit_when_last_browser_closes_(true),
       open_about_blank_on_browser_launch_(true),
       multi_desktop_test_(false)
 #if defined(OS_MACOSX)
       , autorelease_pool_(NULL)
 #endif  // OS_MACOSX
     {
 #if defined(OS_MACOSX)
@@ skipping 128 matching lines @@
 #endif
 
   // TODO(pkotwicz): Investigate if we can remove this switch.
   if (exit_when_last_browser_closes_)
     command_line->AppendSwitch(switches::kDisableZeroBrowsersOpenForTests);
 
   if (open_about_blank_on_browser_launch_ && command_line->GetArgs().empty())
     command_line->AppendArg(url::kAboutBlankURL);
 }
 
+bool InProcessBrowserTest::RunAccessibilityChecks(std::string* error_message) {
+  if (!browser()) {
+    *error_message = "browser is NULL";

[Jay Civelli, 2015/02/07 01:11:12]

Do we want to support |error_message| potentially be NULL?
I wonder if using ASSERT for these was not a better approach. Arguably when you
run this is to get the a11y errors and it's expected that you have an active
browser/tab/frame.

[hcarmona, 2015/02/07 02:22:12]

The error the audit returns is very descriptive about what elements are not
accessible and for what reason. Having |error_message| not populate would make
finding the cause of the error harder.
Should we just assume that all tests will have a browser/tab/frame? If a browser
test run is missing one or more of these does that mean it's in a bad state?

We can also move the asserts up a level to where this method is called and pass
in |web_contents| and |focus_frame|

+    return false;
+  }
+  auto tab_strip = browser()->tab_strip_model();
+  if (!tab_strip) {
+    *error_message = "tab_strip is NULL";
+    return false;
+  }
+  auto web_contents = tab_strip->GetActiveWebContents();
+  if (!web_contents) {
+    *error_message = "web_contents is NULL";
+    return false;
+  }
+  auto focused_frame = web_contents->GetFocusedFrame();
+  if (!focused_frame) {
+    *error_message = "focused_frame is NULL";
+    return false;
+  }
+
+  // Load accessibility library.
+  base::FilePath src_dir;
+  if (!PathService::Get(base::DIR_SOURCE_ROOT, &src_dir)) {
+    *error_message = "PathService::Get failed";
+    return false;
+  }
+  base::FilePath script_path = src_dir.Append(kAXSTesting);
+  std::string script;
+  if (!base::ReadFileToString(script_path, &script)) {
+    *error_message = "Could not read " + script_path.value();
+    return false;
+  }
+  if (!content::ExecuteScript(web_contents, script)) {
+    *error_message = "Failed to load accessibility library";
+    return false;
+  }
+
+  // Run accessibility audit.
+  if (!content::ExecuteScriptAndExtractString(focused_frame,
+                                              kAccessibilityTestString,
+                                              error_message)) {
+    *error_message = "Failed to run accessibility audit";
+    return false;
+  }
+
+  // Test result should be empty if there are no errors.
+  return !error_message->compare("");

[Jay Civelli, 2015/02/07 01:11:12]

Shouldn't we just return true? If someone called this with a non empty
|error_message| then this would return false when it should not.

[hcarmona, 2015/02/07 02:22:12]

We can't return true because running the audit populates |error_message| and we
don't know if the test passed or failed until we check if it's empty.

A non-empty |error_message| will be cleared because running the audit will
overwrite it.

[Jay Civelli, 2015/02/07 02:36:35]

Oh, right.
Nit: you could do return !error_message->empty();

[hcarmona, 2015/02/09 22:55:32]

Done.

+}
+
 bool InProcessBrowserTest::CreateUserDataDirectory() {
   base::CommandLine* command_line = base::CommandLine::ForCurrentProcess();
   base::FilePath user_data_dir =
       command_line->GetSwitchValuePath(switches::kUserDataDir);
   if (user_data_dir.empty()) {
     if (temp_user_data_dir_.CreateUniqueTempDir() &&
         temp_user_data_dir_.IsValid()) {
       user_data_dir = temp_user_data_dir_.path();
     } else {
       LOG(ERROR) << "Could not create temporary user data directory \""
@@ skipping 154 matching lines @@
   // deallocation via an autorelease pool (such as browser window closure and
   // browser shutdown). To avoid this, the following pool is recycled after each
   // time code is directly executed.
   autorelease_pool_ = new base::mac::ScopedNSAutoreleasePool;
 #endif
 
   // Pump any pending events that were created as a result of creating a
   // browser.
   content::RunAllPendingInMessageLoop();
 
+  // run_accessibility_checks_for_test_case_ must be set before calling
+  // SetUpOnMainThread or RunTestOnMainThread so that one or all tests can
+  // enable/disable the accessibility audit.
+  run_accessibility_checks_for_test_case_ = false;
+
   SetUpOnMainThread();
 #if defined(OS_MACOSX)
   autorelease_pool_->Recycle();
 #endif
 
   if (!HasFatalFailure())
     RunTestOnMainThread();
 #if defined(OS_MACOSX)
   autorelease_pool_->Recycle();
 #endif
 
+  if (run_accessibility_checks_for_test_case_) {
+    std::string error_message;
+    EXPECT_TRUE(RunAccessibilityChecks(&error_message));
+    EXPECT_EQ("", error_message);
+  }
+
   // Invoke cleanup and quit even if there are failures. This is similar to
   // gtest in that it invokes TearDown even if Setup fails.
   TearDownOnMainThread();
 #if defined(OS_MACOSX)
   autorelease_pool_->Recycle();
 #endif
 
   // Sometimes tests leave Quit tasks in the MessageLoop (for shame), so let's
   // run all pending messages here to avoid preempting the QuitBrowsers tasks.
   // TODO(jbates) Once crbug.com/134753 is fixed, this can be removed because it
@@ skipping 30 matching lines @@
   // On the Mac, this eventually reaches
   // -[BrowserWindowController windowWillClose:], which will post a deferred
   // -autorelease on itself to ultimately destroy the Browser object. The line
   // below is necessary to pump these pending messages to ensure all Browsers
   // get deleted.
   content::RunAllPendingInMessageLoop();
   delete autorelease_pool_;
   autorelease_pool_ = NULL;
 #endif
 }