Adds skeleton of new integration test framework.

tools/chrome_proxy/webdriver/common.py

Index: tools/chrome_proxy/webdriver/common.py
diff --git a/tools/chrome_proxy/webdriver/common.py b/tools/chrome_proxy/webdriver/common.py
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+# 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.
+
+import argparse
+import json
+import os
+import shlex
+import sys
+import time
+import traceback
+
+sys.path.append(os.path.join(os.path.dirname(__file__), os.pardir, os.pardir,
+  os.pardir, 'third_party', 'webdriver', 'pylib'))
+from selenium import webdriver
+from selenium.webdriver.chrome.options import Options
+
+# TODO(robertogden) add logging
+
+
+def ParseFlags():
+  """
+  Parses the given command line arguments and returns an object with the flags
+  as properties.
+  """
+  parser = argparse.ArgumentParser()
+  parser.add_argument('--browser_args', nargs=1, type=str, help='Override '
+    'browser flags in code with these flags')
+  parser.add_argument('--via_header_matches', metavar='via_header', nargs=1,
+    default='1.1 Chrome-Compression-Proxy', help='What the via should match to '
+    'be considered valid')
+  parser.add_argument('--chrome_exec', nargs=1, type=str, help='The path to '
+    'the Chrome or Chromium executable')
+  parser.add_argument('chrome_driver', nargs=1, type=str, help='The path to '
+    'the ChromeDriver executable')
+  # TODO(robertogden) make this a logging statement
+  print 'DEBUG: Args=', json.dumps(vars(parser.parse_args(sys.argv[1:])))
+  return parser.parse_args(sys.argv[1:])
+
+def HandleException(test_name=None):
+  """
+  Writes the exception being handled and a stack trace to stderr.
+  """
+  sys.stderr.write("**************************************\n")
+  sys.stderr.write("**************************************\n")
+  sys.stderr.write("**                                  **\n")
+  sys.stderr.write("**       UNCAUGHT EXCEPTION         **\n")
+  sys.stderr.write("**                                  **\n")
+  sys.stderr.write("**************************************\n")
+  sys.stderr.write("**************************************\n")
+  if test_name:
+    sys.stderr.write("Failed test: %s" % test_name)
+  traceback.print_exception(*sys.exc_info())
+  sys.exit(1)
+
+class TestDriver:
+  """
+  This class is the tool that is used by every integration test to interact with
+  the Chromium browser and validate proper functionality. This class sits on top
+  of the Selenium Chrome Webdriver with added utility and helper functions for
+  Chrome-Proxy. This class should be used with Python's 'with' operator.
+  """
+
+  def __init__(self):
+    self._flags = ParseFlags()
+    self._driver = None
+    self.chrome_args = {}

[RyanSturm, 2016/11/29 19:31:46]

can this be a set instead of a dict? I don't see much value in setting the key
pair to value : true when you can just add value instead.

[Robert Ogden, 2016/11/29 22:39:36]

Done in follow up CL

+    self._url = ''
+
+  def __enter__(self):
+    return self
+
+  def __exit__(self, exc_type, exc_value, tb):
+    if self._driver:
+      self._StopDriver()
+
+  def _OverrideChromeArgs(self):
+    """
+    Overrides any given flags in the code with those given on the command line.
+    """
+    if self._flags.browser_args and len(self._flags.browser_args) > 0:
+      for a in shlex.split(self._flags.browser_args):
+        self.chrome_args[a] = True
+
+  def _StartDriver(self):
+    """
+    Parses the flags to pass to Chromium, then starts the ChromeDriver.
+    """
+    opts = Options()
+    for a in self.chrome_args:
+      opts.add_argument(a)
+    caps = {'loggingPrefs': {'performance': 'INFO'}}
+    if self._flags.chrome_exec:
+      caps['chrome.binary'] = self._flags.chrome_exec
+    driver = webdriver.Chrome(executable_path=self._flags.chrome_driver[0],
+      chrome_options=opts, desired_capabilities=caps)
+    driver.command_executor._commands.update({
+      'getAvailableLogTypes': ('GET', '/session/$sessionId/log/types'),
+      'getLog': ('POST', '/session/$sessionId/log')})
+    self._driver = driver
+
+  def _StopDriver(self):
+    """
+    Nicely stops the ChromeDriver.
+    """
+    self._driver.quit()
+    del self._driver
+
+  def AddChromeArgs(self, args):
+    """
+    Adds multiple arguments that will be passed to Chromium at start.
+    """
+    if not self.chrome_args:
+      self.chrome_args = {}
+    for a in args:
+      self.chrome_args[a] = True
+
+  def AddChromeArg(self, arg):
+    """
+    Adds a single argument that will be passed to Chromium at start.
+    """
+    if not self.chrome_args:
+      self.chrome_args = {}
+    self.chrome_args[arg] = True
+
+  def RemoveChromeArgs(self, args):
+    """
+    Removes multiple arguments that will no longer be passed to Chromium at
+    start.
+    """
+    if not self.chrome_args:
+      self.chrome_args = {}
+      return
+    for a in args:
+      del self.chrome_args[a]
+
+  def RemoveChromeArg(self, arg):
+    """
+    Removes a single argument that will no longer be passed to Chromium at
+    start.
+    """
+    if not self.chrome_args:
+      self.chrome_args = {}
+      return
+    del self.chrome_args[arg]
+
+  def ClearChromeArgs(self):
+    """
+    Removes all arguments from Chromium at start.
+    """
+    self.chrome_args = {}
+
+  def ClearCache(self):
+    """
+    Clears the browser cache. Important note: ChromeDriver automatically starts
+    a clean copy of Chrome on every instantiation.
+    """
+    self.ExecuteJavascript('if(window.chrome && chrome.benchmarking && '
+      'chrome.benchmarking.clearCache){chrome.benchmarking.clearCache(); '
+      'chrome.benchmarking.clearPredictorCache();chrome.benchmarking.'
+      'clearHostResolverCache();}')
+
+  # TODO(robertogden) use a smart page instead
+  def SetURL(self, url):
+    """
+    Sets the URL that the browser will navigate to during the test.
+    """
+    self._url = url
+
+  # TODO(robertogden) add timeout
+  def LoadPage(self):
+    """
+    Starts Chromium with any arguments previously given and navigates to the
+    previously given URL.
+    """
+    if not self._driver:
+      self._StartDriver()
+    self._driver.get(self._url)
+
+  # TODO(robertogden) add timeout
+  def ExecuteJavascript(self, script):
+    """
+    Executes the given javascript in the browser's current page as if it were on
+    the console. Returns a string of whatever the evaluation was.
+    """
+    if not self._driver:
+      self._StartDriver()
+    return self._driver.execute_script("return " + script)

[RyanSturm, 2016/11/29 19:31:46]

What happens if LoadPage was not called (i.e., _StartDriver was just called)?

[Robert Ogden, 2016/11/29 22:39:36]

Chrome would start but would stay on a blank page.

+
+
+class IntegrationTest:
+  """
+  A parent class for all integration tests with utility and assertion methods.
+  All methods starting with the word 'test' (ignoring case) will be called with
+  the RunAllTests() method which can be used in place of a main method.
+  """
+  def RunAllTests(self):
+    """
+    Runs all methods starting with the word 'test' (ignoring case) in the class.
+    Can be used in place of a main method to run all tests in a class.
+    """
+    methodList = [method for method in dir(self) if callable(getattr(self,
+      method)) and method.lower().startswith('test')]
+    for method in methodList:
+      try:
+        getattr(self, method)()
+      except Exception as e:
+        HandleException(method)
+
+  # TODO(robertogden) add some nice assertion functions
+
+  def Fail(self, msg):
+    sys.stderr.write("**************************************\n")
+    sys.stderr.write("**************************************\n")
+    sys.stderr.write("**                                  **\n")
+    sys.stderr.write("**          TEST FAILURE            **\n")
+    sys.stderr.write("**                                  **\n")
+    sys.stderr.write("**************************************\n")
+    sys.stderr.write("**************************************\n")
+    sys.stderr.write(msg, '\n')
+    sys.exit(1)