[I-Spy] Add support for rebaselining expectations from the web UI.

chrome/test/functional/ispy/client/chrome_utils.py

-# Copyright 2013 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 json
-import logging
-import os
-import time
-from distutils.version import LooseVersion
-from PIL import Image
-
-from ..common import cloud_bucket
-from ..common import ispy_utils
-
-
-class ChromeUtils(object):
-  """A utility for using ISpy with Chrome."""
-
-  def __init__(self, cloud_bucket, version_file, screenshot_func):
-    """Initializes the utility class.
-
-    Args:
-      cloud_bucket: a BaseCloudBucket in which to the version file,
-          expectations and results are to be stored.
-      version_file: path to the version file in the cloud bucket. The version
-          file contains a json list of ordered Chrome versions for which
-          expectations exist.
-      screenshot_func: a function that returns a PIL.Image.
-    """
-    self._cloud_bucket = cloud_bucket
-    self._version_file = version_file
-    self._screenshot_func = screenshot_func
-    self._ispy = ispy_utils.ISpyUtils(self._cloud_bucket)
-    with open(
-        os.path.join(os.path.dirname(__file__), 'wait_on_ajax.js'), 'r') as f:
-      self._wait_for_unchanging_dom_script = f.read()
-
-  def UpdateExpectationVersion(self, chrome_version):
-    """Updates the most recent expectation version to the Chrome version.
-
-    Should be called after generating a new set of expectations.
-
-    Args:
-      chrome_version: the chrome version as a string of the form "31.0.123.4".
-    """
-    insert_pos = 0
-    expectation_versions = []
-    try:
-      expectation_versions = self._GetExpectationVersionList()
-      if expectation_versions:
-        try:
-          version = self._GetExpectationVersion(
-              chrome_version, expectation_versions)
-          if version == chrome_version:
-            return
-          insert_pos = expectation_versions.index(version)
-        except:
-          insert_pos = len(expectation_versions)
-    except cloud_bucket.FileNotFoundError:
-      pass
-    expectation_versions.insert(insert_pos, chrome_version)
-    logging.info('Updating expectation version...')
-    self._cloud_bucket.UploadFile(
-        self._version_file, json.dumps(expectation_versions),
-        'application/json')
-
-  def _GetExpectationVersion(self, chrome_version, expectation_versions):
-    """Returns the expectation version for the given Chrome version.
-
-    Args:
-      chrome_version: the chrome version as a string of the form "31.0.123.4".
-      expectation_versions: Ordered list of Chrome versions for which
-        expectations exist, as stored in the version file.
-
-    Returns:
-      Expectation version string.
-    """
-    # Find the closest version that is not greater than the chrome version.
-    for version in expectation_versions:
-      if LooseVersion(version) <= LooseVersion(chrome_version):
-        return version
-    raise Exception('No expectation exists for Chrome %s' % chrome_version)
-
-  def _GetExpectationVersionList(self):
-    """Gets the list of expectation versions from google storage."""
-    return json.loads(self._cloud_bucket.DownloadFile(self._version_file))
-
-  def _GetExpectationNameWithVersion(self, device_type, expectation,
-                                     chrome_version):
-    """Get the expectation to be used with the current Chrome version.
-
-    Args:
-      device_type: string identifier for the device type.
-      expectation: name for the expectation to generate.
-      chrome_version: the chrome version as a string of the form "31.0.123.4".
-
-    Returns:
-      Version as an integer.
-    """
-    version = self._GetExpectationVersion(
-        chrome_version, self._GetExpectationVersionList())
-    return self._CreateExpectationName(device_type, expectation, version)
-
-  def _CreateExpectationName(self, device_type, expectation, version):
-    """Create the full expectation name from the expectation and version.
-
-    Args:
-      device_type: string identifier for the device type, example: mako
-      expectation: base name for the expectation, example: google.com
-      version: expectation version, example: 31.0.23.1
-
-    Returns:
-      Full expectation name as a string, example: mako:google.com(31.0.23.1)
-    """
-    return '%s:%s(%s)' % (device_type, expectation, version)
-
-  def GenerateExpectation(self, device_type, expectation, chrome_version):
-    """Take screenshots and store as an expectation in I-Spy.
-
-    Args:
-      device_type: string identifier for the device type.
-      expectation: name for the expectation to generate.
-      chrome_version: the chrome version as a string of the form "31.0.123.4".
-    """
-    # https://code.google.com/p/chromedriver/issues/detail?id=463
-    time.sleep(1)
-    expectation_with_version = self._CreateExpectationName(
-        device_type, expectation, chrome_version)
-    if self._ispy.ExpectationExists(expectation_with_version):
-      logging.warning(
-          'I-Spy expectation \'%s\' already exists, overwriting.',
-          expectation_with_version)
-    screenshots = [self._screenshot_func() for _ in range(8)]
-    logging.info('Generating I-Spy expectation...')
-    self._ispy.GenerateExpectation(expectation_with_version, screenshots)
-
-  def PerformComparison(self, test_run, device_type, expectation,
-                        chrome_version):
-    """Take a screenshot and compare it with the given expectation in I-Spy.
-
-    Args:
-      test_run: name for the test run.
-      device_type: string identifier for the device type.
-      expectation: name for the expectation to compare against.
-      chrome_version: the chrome version as a string of the form "31.0.123.4".
-    """
-    # https://code.google.com/p/chromedriver/issues/detail?id=463
-    time.sleep(1)
-    screenshot = self._screenshot_func()
-    logging.info('Performing I-Spy comparison...')
-    self._ispy.PerformComparison(
-        test_run,
-        self._GetExpectationNameWithVersion(
-            device_type, expectation, chrome_version),
-        screenshot)
-
-  def GetScriptToWaitForUnchangingDOM(self):
-    """Returns a JavaScript script that waits for the DOM to stop changing."""
-    return self._wait_for_unchanging_dom_script
-