telemetry/telemetry/testing/options_for_unittests.py

# Copyright 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.

"""This module provides the global variable options_for_unittests.

This is set to a BrowserOptions object by the test harness, or None
if unit tests are not running.

This allows multiple unit tests to use a specific
browser, in face of multiple options."""

import os

from telemetry.internal import story_runner
from telemetry.testing import fakes


_options = []


def Push(options):
  _options.append(options)


def Pop():
  return _options.pop()


def GetCopy():
  if not AreSet():
    return None
  return _options[-1].Copy()


def AreSet():
  return bool(_options)


def GetRunOptions(output_dir=None, fake_browser=False, benchmark_cls=None,
                  overrides=None, environment=None):
  """Get an options object filled in necessary defaults for the Run command.

  Args:
    output_dir: A directory to be used for writing outputs and artifacts.
      Usually the caller will create a temporary directory and pass its path
      here. Note that it is an error to leave the output_dir as None and pass
      the returned options object to results_options.CreateResults.
    fake_browser: Whether to create an options object that always "finds" a
      fakes.FakePossibleBrowser. The default is to instead use the browser
      selected on the command line of the test runner.
    benchmark_cls: An optional benchmark class. If given, the benchmark will
      also be given an oportunity to define and process additional arguments.
    overrides: An optional dictionary with option values to override *before*
      options are processed by benchmark and story runner. In most situations
      this should not be needed, in most cases tests can just adjust options on
      the returned object as they see fit. TODO(crbug.com/985712): This should
      not be required, ideally the processing of options should not change the
      internal state of Telemetry objects.
    environment: The ProjectConfig to run within.

  Returns:
    An options object with default values for all command line arguments.
  """
  if fake_browser:
    options = fakes.CreateBrowserFinderOptions()
  else:
    options = GetCopy()  # A copy of the unittest options.
  parser = options.CreateParser()
  if benchmark_cls is not None:
    benchmark_cls.AddCommandLineArgs(parser)
  story_runner.AddCommandLineArgs(parser)
  if benchmark_cls is not None:
    benchmark_cls.SetArgumentDefaults(parser)
  options.MergeDefaultValues(parser.get_default_values())
  if overrides:
    for name, value in overrides.items():
      if not hasattr(options, name):
        raise AttributeError('Options object has no attribute: %s' % name)
      setattr(options, name, value)
  if benchmark_cls is not None:
    benchmark_cls.ProcessCommandLineArgs(parser, options)
  story_runner.ProcessCommandLineArgs(parser, options, environment)
  options.suppress_gtest_report = True
  options.output_dir = output_dir
  if output_dir is not None:
    options.intermediate_dir = os.path.join(output_dir, 'artifacts')
  # TODO(crbug.com/928275): Remove these when Telemetry tests no longer
  # depend on any result processing options.
  options.output_formats = ['none']
  options.upload_results = False
  options.upload_bucket = None
  return options