tools/perf/measurements/v8_detached_context_age_in_gc_unittest.py

# Copyright 2015 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.

from telemetry.internal.results import page_test_results
from telemetry.page import page as page_module
from telemetry.testing import options_for_unittests
from telemetry.testing import page_test_test_case
from telemetry.util import wpr_modes

from measurements import v8_detached_context_age_in_gc


class FakePage(page_module.Page):

  def __init__(self, url):
    super(FakePage, self).__init__(url=url)

  @property
  def is_file(self):
    return self._url.startswith('file://')


class FakeTab(object):

  def __init__(self, histograms):
    self.histograms = histograms
    self.current_histogram_index = 0

  def EvaluateJavaScript(self, script):
    if 'V8.DetachedContextAgeInGC' in script:
      self.current_histogram_index += 1
      return self.histograms[self.current_histogram_index - 1]
    return '{}'

  def CollectGarbage(self):
    pass


def _MeasureFakePage(histograms):
  results = page_test_results.PageTestResults()
  page = FakePage('file://blank.html')
  tab = FakeTab(histograms)
  metric = v8_detached_context_age_in_gc.V8DetachedContextAgeInGC()
  results.WillRunPage(page)
  metric.DidNavigateToPage(page, tab)
  metric.ValidateAndMeasurePage(page, tab, results)
  results.DidRunPage(page)
  return results


def _ActualValues(results):
  return dict((v.name, v) for v in results.all_page_specific_values)


class SimplePage(page_module.Page):

  def __init__(self, page_set):
    super(SimplePage, self).__init__(
        'file://host.html', page_set, page_set.base_dir)

  def RunPageInteractions(self, action_runner):
    # Reload the page to detach the previous context.
    action_runner.ReloadPage()


class V8DetachedContextAgeInGCTests(page_test_test_case.PageTestTestCase):

  def setUp(self):
    self._options = options_for_unittests.GetCopy()
    self._options.browser_options.wpr_mode = wpr_modes.WPR_OFF

  def testWithNoData(self):
    histograms = [
        """{"count": 0, "buckets": []}""",
        """{"count": 0, "buckets": []}"""
    ]
    results = _MeasureFakePage(histograms)
    actual = _ActualValues(results)
    self.assertTrue('skip' in actual)
    self.assertFalse('V8_DetachedContextAgeInGC' in actual)

  def testWithData(self):
    histograms = [
        """{"count": 3, "buckets": [{"low": 1, "high": 2, "count": 1},
                                    {"low": 2, "high": 3, "count": 2}]}""",
        """{"count": 4, "buckets": [{"low": 1, "high": 2, "count": 2},
                                    {"low": 2, "high": 3, "count": 2}]}""",
    ]
    results = _MeasureFakePage(histograms)
    actual = _ActualValues(results)['V8_DetachedContextAgeInGC']
    self.assertEqual(2, actual.value)
    self.assertEqual('garbage_collections', actual.units)

  def testWithSimplePage(self):
    page_set = self.CreateEmptyPageSet()
    page = SimplePage(page_set)
    page_set.AddStory(page)
    metric = v8_detached_context_age_in_gc.V8DetachedContextAgeInGC()
    results = self.RunMeasurement(metric, page_set, options=self._options)
    self.assertEquals(0, len(results.failures), msg=str(results.failures))
    actual = _ActualValues(results)['V8_DetachedContextAgeInGC']
    self.assertLessEqual(0, actual.value)
    self.assertEqual('garbage_collections', actual.units)