Add a script to test Chrome with the NVDA screen reader.

tools/accessibility/nvda/nvda_chrome_tests.py

+#!/usr/bin/env python
+# Copyright 2014 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.
+
+"""Semi-automated tests of Chrome with NVDA.
+
+This file performs (semi) automated tests of Chrome with NVDA
+(NonVisual Desktop Access), a popular open-source screen reader for
+visually impaired users on Windows. It works by launching Chrome in a
+subprocess, then launching NVDA in a special environment that simulates
+speech rather than actually speaking, and ignores all events coming from
+processes other than a specific Chrome process ID. Each test automates
+Chrome with a series of actions and asserts that NVDA gives the expected
+feedback in response.
+
+The tests are "semi" automated in the sense that they are not intended to be
+run from any developer machine, or on a buildbot - it requires setting up the
+environment according to the instructions in README.txt, then running the
+test script, then filing bugs for any potential failures. If the environment
+is set up correctly, the actual tests should run automatically and unattended.
+"""
+
+import os
+import pywinauto
+import re
+import shutil
+import signal
+import subprocess
+import sys
+import tempfile
+import time
+import unittest
+
+CHROME_PROFILES_PATH = os.path.join(os.getcwd(), 'chrome_profiles')
+CHROME_PATH = os.path.join(os.environ['USERPROFILE'],
+                           'AppData',
+                           'Local',
+                           'Google',
+                           'Chrome SxS',
+                           'Application',
+                           'chrome.exe')
+NVDA_PATH = os.path.join(os.getcwd(),
+                         'nvdaPortable',
+                         'nvda_noUIAccess.exe')
+NVDA_PROCTEST_PATH = os.path.join(os.getcwd(),
+                                  'nvda-proctest')
+NVDA_LOGPATH = os.path.join(os.getcwd(),
+                            'nvda_log.txt')
+WAIT_FOR_SPEECH_TIMEOUT_SECS = 3.0
+
+class NvdaChromeTest(unittest.TestCase):
+  @classmethod
+  def setUpClass(cls):
+    print 'user data: %s' % CHROME_PROFILES_PATH
+    print 'chrome: %s' % CHROME_PATH
+    print 'nvda: %s' % NVDA_PATH
+    print 'nvda_proctest: %s' % NVDA_PROCTEST_PATH
+
+    print
+    print 'Clearing user data directory and log file from previous runs'
+    if os.access(NVDA_LOGPATH, os.F_OK):
+      os.remove(NVDA_LOGPATH)
+    if os.access(CHROME_PROFILES_PATH, os.F_OK):
+      shutil.rmtree(CHROME_PROFILES_PATH)
+    os.mkdir(CHROME_PROFILES_PATH, 0777)
+
+    def handler(signum, frame):
+      print 'Test interrupted, attempting to kill subprocesses.'
+      self.tearDown()
+      sys.exit()
+    signal.signal(signal.SIGINT, handler)
+
+  def setUp(self):
+    user_data_dir = tempfile.mkdtemp(dir = CHROME_PROFILES_PATH)
+    args = [CHROME_PATH,
+            '--user-data-dir=%s' % user_data_dir,
+            '--no-first-run',
+            'about:blank']
+    print
+    print ' '.join(args)
+    self._chrome_proc = subprocess.Popen(args)
+    self._chrome_proc.poll()
+    if self._chrome_proc.returncode is None:
+      print 'Chrome is running'
+    else:
+      print 'Chrome exited with code', self._chrome_proc.returncode
+      sys.exit()
+    print 'Chrome pid: %d' % self._chrome_proc.pid
+
+    os.environ['NVDA_SPECIFIC_PROCESS'] = str(self._chrome_proc.pid)
+
+    args = [NVDA_PATH,
+            '-m',
+            '-c',
+            NVDA_PROCTEST_PATH,
+            '-f',
+            NVDA_LOGPATH]
+    self._nvda_proc = subprocess.Popen(args)
+    self._nvda_proc.poll()
+    if self._nvda_proc.returncode is None:
+      print 'NVDA is running'
+    else:
+      print 'NVDA exited with code', self._nvda_proc.returncode
+      sys.exit()
+    print 'NVDA pid: %d' % self._nvda_proc.pid
+
+    app = pywinauto.application.Application()
+    app.connect_(process = self._chrome_proc.pid)
+    self._pywinauto_window = app.top_window_()
+
+    try:
+      self._WaitForSpeech(['Address and search bar edit', 'about:blank'])
+    except:
+      self.tearDown()
+
+  def tearDown(self):
+    print
+    print 'Shutting down'
+
+    self._chrome_proc.poll()
+    if self._chrome_proc.returncode is None:
+      print 'Killing Chrome subprocess'
+      self._chrome_proc.kill()
+    else:
+      print 'Chrome already died.'
+
+    self._nvda_proc.poll()
+    if self._nvda_proc.returncode is None:
+      print 'Killing NVDA subprocess'
+      self._nvda_proc.kill()
+    else:
+      print 'NVDA already died.'
+
+  def _GetSpeechFromNvdaLogFile(self):
+    """Return everything NVDA would have spoken as a list of strings.
+
+    Parses lines like this from NVDA's log file:
+      Speaking [LangChangeCommand ('en'), u'Google Chrome', u'window']
+      Speaking character u'slash'
+
+    Returns a single list of strings like this:
+      [u'Google Chrome', u'window', u'slash']
+    """
+    if not os.access(NVDA_LOGPATH, os.F_OK):
+      return []
+    lines = open(NVDA_LOGPATH).readlines()
+    regex = re.compile(r"u'((?:[^\'\\]|\\.)*)\'")
+    result = []
+    for line in lines:
+      for m in regex.finditer(line):
+        speech_with_whitespace = m.group(1)
+        speech_stripped = re.sub(r'\s+', ' ', speech_with_whitespace).strip()
+        result.append(speech_stripped)
+    return result
+
+  def _WaitForSpeech(self, expected):
+    """Block until the last speech in NVDA's log file is the given string(s).
+
+    Repeatedly parses the log file until the last speech line(s) in the
+    log file match the given strings, or it times out.
+
+    Args:
+      expected: string or a list of string - only succeeds if these are the last
+        strings spoken, in order.
+
+    Returns when those strings are spoken, or throws an error if it times out
+      waiting for those strings.
+    """
+    if type(expected) is type(''):
+      expected = [expected]
+    start_time = time.time()
+    while True:
+      lines = self._GetSpeechFromNvdaLogFile()
+      if (lines[-len(expected):] == expected):
+        break
+
+      if time.time() - start_time >= WAIT_FOR_SPEECH_TIMEOUT_SECS:
+        print '** Speech from NVDA so far:'
+        for line in lines:
+          print '"%s"' % line
+        print '** Was waiting for:'
+        for line in expected:
+          print '"%s"' % line
+        raise Exception('Timed out')
+      time.sleep(0.1)
+
+  #
+  # Tests
+  #
+
+  def testTypingInOmnibox(self):
+    # Ctrl+A: Select all.
+    self._pywinauto_window.TypeKeys('^A')
+    self._WaitForSpeech('selecting about:blank')
+
+    # Type three characters.
+    self._pywinauto_window.TypeKeys('xyz')
+    self._WaitForSpeech(['x', 'y', 'z'])
+
+    # Arrow back over two characters.
+    self._pywinauto_window.TypeKeys('{LEFT}')
+    self._WaitForSpeech(['z', 'z', 'unselecting'])
+
+    self._pywinauto_window.TypeKeys('{LEFT}')
+    self._WaitForSpeech('y')
+
+  def testFocusToolbarButton(self):
+    # Alt+Shift+T.
+    self._pywinauto_window.TypeKeys('%+T')
+    self._WaitForSpeech('Reload button Reload this page')
+
+  def testReadAllOnPageLoad(self):
+    # Ctrl+A: Select all
+    self._pywinauto_window.TypeKeys('^A')
+    self._WaitForSpeech('selecting about:blank')
+
+    # Load data url.
+    self._pywinauto_window.TypeKeys('data:text/html,Hello<p>World.')
+    self._WaitForSpeech('dot')
+    self._pywinauto_window.TypeKeys('{ENTER}')
+    self._WaitForSpeech(
+        ['document',
+         'Hello',
+         'World.'])
+
+if __name__ == '__main__':
+  unittest.main()
+