Revert of [Telemetry] Migrate browser_test_runner to use typ as the test runner

telemetry/telemetry/testing/browser_test_runner.py

Index: telemetry/telemetry/testing/browser_test_runner.py
diff --git a/telemetry/telemetry/testing/browser_test_runner.py b/telemetry/telemetry/testing/browser_test_runner.py
index 5d883c88e91f77f263ec935fe73406c161238c36..7c8ed1b51eda4857cebddd3e94439e4b2e22c39f 100644
--- a/telemetry/telemetry/testing/browser_test_runner.py
+++ b/telemetry/telemetry/testing/browser_test_runner.py
@@ -1,37 +1,313 @@
 # 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 os
-import subprocess
-import sys
-
-from telemetry.core import util
-
-
-def Run(project_config, args):
-  assert '--top-level-dir' not in args, (
-      'Top level directory for running tests should be specified through '
-      'the instance of telemetry.project_config.ProjectConfig.')
-  assert '--client-config' not in args, (
-      'Client config file to be used for telemetry should be specified through '
-      'the instance of telemetry.project_config.ProjectConfig.')
-  assert project_config.top_level_dir, 'Must specify top level dir for project'
-  args.extend(['--top-level-dir', project_config.top_level_dir])
-  for c in project_config.client_configs:
-    args.extend(['--client-config', c])
-  for s in project_config.start_dirs:
-    args.extend(['--start-dir', s])
-
-  if project_config.default_chrome_root and not '--chrome-root' in args:
-    args.extend(['--chrome-root', project_config.default_chrome_root])
-
-  env = os.environ.copy()
-  telemetry_dir = util.GetTelemetryDir()
-  if 'PYTHONPATH' in env:
-    env['PYTHONPATH'] = os.pathsep.join([env['PYTHONPATH'], telemetry_dir])
+
+import argparse
+import json
+import logging
+import re
+import time
+import unittest
+
+from telemetry.core import discover
+from telemetry.internal.browser import browser_options
+from telemetry.internal.util import binary_manager
+from telemetry.testing import options_for_unittests
+from telemetry.testing import serially_executed_browser_test_case
+
+DEFAULT_LOG_FORMAT = (
+  '(%(levelname)s) %(asctime)s %(module)s.%(funcName)s:%(lineno)d  '
+  '%(message)s')
+
+
+def ProcessCommandLineOptions(test_class, project_config, args):
+  options = browser_options.BrowserFinderOptions()
+  options.browser_type = 'any'
+  parser = options.CreateParser(test_class.__doc__)
+  test_class.AddCommandlineArgs(parser)
+  # Set the default chrome root variable. This is required for the
+  # Android browser finder to function properly.
+  parser.set_defaults(chrome_root=project_config.default_chrome_root)
+  finder_options, positional_args = parser.parse_args(args)
+  finder_options.positional_args = positional_args
+  options_for_unittests.Push(finder_options)
+  # Use this to signal serially_executed_browser_test_case.LoadAllTestsInModule
+  # not to load tests in cases it's not invoked by browser_test_runner
+  # framework.
+  finder_options.browser_test_runner_running = True
+  return finder_options
+
+
+def _ValidateDistinctNames(browser_test_classes):
+  names_to_test_classes = {}
+  for cl in browser_test_classes:
+    name = cl.Name()
+    if name in names_to_test_classes:
+      raise Exception('Test name %s is duplicated between %s and %s' % (
+          name, repr(cl), repr(names_to_test_classes[name])))
+    names_to_test_classes[name] = cl
+
+
+def _TestRangeForShard(total_shards, shard_index, num_tests):
+  """Returns a 2-tuple containing the start (inclusive) and ending
+  (exclusive) indices of the tests that should be run, given that
+  |num_tests| tests are split across |total_shards| shards, and that
+  |shard_index| is currently being run.
+  """
+  assert num_tests >= 0
+  assert total_shards >= 1
+  assert shard_index >= 0 and shard_index < total_shards, (
+    'shard_index (%d) must be >= 0 and < total_shards (%d)' %
+    (shard_index, total_shards))
+  if num_tests == 0:
+    return (0, 0)
+  floored_tests_per_shard = num_tests // total_shards
+  remaining_tests = num_tests % total_shards
+  if remaining_tests == 0:
+    return (floored_tests_per_shard * shard_index,
+            floored_tests_per_shard * (1 + shard_index))
+  # More complicated. Some shards will run floored_tests_per_shard
+  # tests, and some will run 1 + floored_tests_per_shard.
+  num_earlier_shards_with_one_extra_test = min(remaining_tests, shard_index)
+  num_earlier_shards_with_no_extra_tests = max(
+    0, shard_index - num_earlier_shards_with_one_extra_test)
+  num_earlier_tests = (
+    num_earlier_shards_with_one_extra_test * (floored_tests_per_shard + 1) +
+    num_earlier_shards_with_no_extra_tests * floored_tests_per_shard)
+  tests_for_this_shard = floored_tests_per_shard
+  if shard_index < remaining_tests:
+    tests_for_this_shard += 1
+  return (num_earlier_tests, num_earlier_tests + tests_for_this_shard)
+
+
+def _MedianTestTime(test_times):
+  times = test_times.values()
+  times.sort()
+  if len(times) == 0:
+    return 0
+  halfLen = len(times) / 2
+  if len(times) % 2:
+    return times[halfLen]
   else:
-    env['PYTHONPATH'] = telemetry_dir
-
-  path_to_run_tests = os.path.join(os.path.abspath(os.path.dirname(__file__)),
-                                   'run_browser_tests.py')
-  return subprocess.call([sys.executable, path_to_run_tests] + args, env=env)
+    return 0.5 * (times[halfLen - 1] + times[halfLen])
+
+
+def _TestTime(test, test_times, default_test_time):
+  return test_times.get(test.shortName()) or default_test_time
+
+
+def _DebugShardDistributions(shards, test_times):
+  for i, s in enumerate(shards):
+    num_tests = len(s)
+    if test_times:
+      median = _MedianTestTime(test_times)
+      shard_time = 0.0
+      for t in s:
+        shard_time += _TestTime(t, test_times, median)
+      print 'shard %d: %d seconds (%d tests)' % (i, shard_time, num_tests)
+    else:
+      print 'shard %d: %d tests (unknown duration)' % (i, num_tests)
+
+
+def _SplitShardsByTime(test_cases, total_shards, test_times,
+                       debug_shard_distributions):
+  median = _MedianTestTime(test_times)
+  shards = []
+  for i in xrange(total_shards):
+    shards.append({'total_time': 0.0, 'tests': []})
+  test_cases.sort(key=lambda t: _TestTime(t, test_times, median),
+                  reverse=True)
+
+  # The greedy algorithm has been empirically tested on the WebGL 2.0
+  # conformance tests' times, and results in an essentially perfect
+  # shard distribution of 530 seconds per shard. In the same scenario,
+  # round-robin scheduling resulted in shard times spread between 502
+  # and 592 seconds, and the current alphabetical sharding resulted in
+  # shard times spread between 44 and 1591 seconds.
+
+  # Greedy scheduling. O(m*n), where m is the number of shards and n
+  # is the number of test cases.
+  for t in test_cases:
+    min_shard_index = 0
+    min_shard_time = None
+    for i in xrange(total_shards):
+      if min_shard_time is None or shards[i]['total_time'] < min_shard_time:
+        min_shard_index = i
+        min_shard_time = shards[i]['total_time']
+    shards[min_shard_index]['tests'].append(t)
+    shards[min_shard_index]['total_time'] += _TestTime(t, test_times, median)
+
+  res = [s['tests'] for s in shards]
+  if debug_shard_distributions:
+    _DebugShardDistributions(res, test_times)
+
+  return res
+
+
+def _LoadTests(test_class, finder_options, filter_regex_str,
+               filter_tests_after_sharding,
+               total_shards, shard_index, test_times,
+               debug_shard_distributions):
+  test_cases = []
+  real_regex = re.compile(filter_regex_str)
+  noop_regex = re.compile('')
+  if filter_tests_after_sharding:
+    filter_regex = noop_regex
+    post_filter_regex = real_regex
+  else:
+    filter_regex = real_regex
+    post_filter_regex = noop_regex
+
+  for t in serially_executed_browser_test_case.GenerateTestCases(
+      test_class, finder_options):
+    if filter_regex.search(t.shortName()):
+      test_cases.append(t)
+
+  if test_times:
+    # Assign tests to shards.
+    shards = _SplitShardsByTime(test_cases, total_shards, test_times,
+                                debug_shard_distributions)
+    return [t for t in shards[shard_index]
+            if post_filter_regex.search(t.shortName())]
+  else:
+    test_cases.sort(key=lambda t: t.shortName())
+    test_range = _TestRangeForShard(total_shards, shard_index, len(test_cases))
+    if debug_shard_distributions:
+      tmp_shards = []
+      for i in xrange(total_shards):
+        tmp_range = _TestRangeForShard(total_shards, i, len(test_cases))
+        tmp_shards.append(test_cases[tmp_range[0]:tmp_range[1]])
+      # Can edit the code to get 'test_times' passed in here for
+      # debugging and comparison purposes.
+      _DebugShardDistributions(tmp_shards, None)
+    return [t for t in test_cases[test_range[0]:test_range[1]]
+            if post_filter_regex.search(t.shortName())]
+
+
+class TestRunOptions(object):
+  def __init__(self):
+    self.verbosity = 2
+
+
+class BrowserTestResult(unittest.TextTestResult):
+  def __init__(self, *args, **kwargs):
+    super(BrowserTestResult, self).__init__(*args, **kwargs)
+    self.successes = []
+    self.times = {}
+    self._current_test_start_time = 0
+
+  def addSuccess(self, test):
+    super(BrowserTestResult, self).addSuccess(test)
+    self.successes.append(test)
+
+  def startTest(self, test):
+    super(BrowserTestResult, self).startTest(test)
+    self._current_test_start_time = time.time()
+
+  def stopTest(self, test):
+    super(BrowserTestResult, self).stopTest(test)
+    self.times[test.shortName()] = (time.time() - self._current_test_start_time)
+
+
+def Run(project_config, test_run_options, args, **log_config_kwargs):
+  # the log level is set in browser_options
+  log_config_kwargs.pop('level', None)
+  log_config_kwargs.setdefault('format', DEFAULT_LOG_FORMAT)
+  logging.basicConfig(**log_config_kwargs)
+
+  binary_manager.InitDependencyManager(project_config.client_configs)
+  parser = argparse.ArgumentParser(description='Run a browser test suite')
+  parser.add_argument('test', type=str, help='Name of the test suite to run')
+  parser.add_argument(
+      '--write-abbreviated-json-results-to', metavar='FILENAME', action='store',
+      help=('If specified, writes the full results to that path in json form.'))
+  parser.add_argument('--test-filter', type=str, default='', action='store',
+      help='Run only tests whose names match the given filter regexp.')
+  parser.add_argument('--total-shards', default=1, type=int,
+      help='Total number of shards being used for this test run. (The user of '
+      'this script is responsible for spawning all of the shards.)')
+  parser.add_argument('--shard-index', default=0, type=int,
+      help='Shard index (0..total_shards-1) of this test run.')
+  parser.add_argument(
+    '--filter-tests-after-sharding', default=False, action='store_true',
+    help=('Apply the test filter after tests are split for sharding. Useful '
+          'for reproducing bugs related to the order in which tests run.'))
+  parser.add_argument(
+      '--read-abbreviated-json-results-from', metavar='FILENAME',
+      action='store', help=(
+        'If specified, reads abbreviated results from that path in json form. '
+        'The file format is that written by '
+        '--write-abbreviated-json-results-to. This information is used to more '
+        'evenly distribute tests among shards.'))
+  parser.add_argument('--debug-shard-distributions',
+      action='store_true', default=False,
+      help='Print debugging information about the shards\' test distributions')
+
+  option, extra_args = parser.parse_known_args(args)
+
+  for start_dir in project_config.start_dirs:
+    modules_to_classes = discover.DiscoverClasses(
+        start_dir, project_config.top_level_dir,
+        base_class=serially_executed_browser_test_case.
+            SeriallyExecutedBrowserTestCase)
+    browser_test_classes = modules_to_classes.values()
+
+  _ValidateDistinctNames(browser_test_classes)
+
+  test_class = None
+  for cl in browser_test_classes:
+    if cl.Name() == option.test:
+      test_class = cl
+      break
+
+  if not test_class:
+    print 'Cannot find test class with name matching %s' % option.test
+    print 'Available tests: %s' % '\n'.join(
+        cl.Name() for cl in browser_test_classes)
+    return 1
+
+  options = ProcessCommandLineOptions(test_class, project_config, extra_args)
+
+  test_times = None
+  if option.read_abbreviated_json_results_from:
+    with open(option.read_abbreviated_json_results_from, 'r') as f:
+      abbr_results = json.load(f)
+      test_times = abbr_results.get('times')
+
+  suite = unittest.TestSuite()
+  for test in _LoadTests(test_class, options, option.test_filter,
+                         option.filter_tests_after_sharding,
+                         option.total_shards, option.shard_index,
+                         test_times, option.debug_shard_distributions):
+    suite.addTest(test)
+
+  results = unittest.TextTestRunner(
+      verbosity=test_run_options.verbosity,
+      resultclass=BrowserTestResult).run(suite)
+  if option.write_abbreviated_json_results_to:
+    with open(option.write_abbreviated_json_results_to, 'w') as f:
+      json_results = {'failures': [], 'successes': [],
+                      'times': {}, 'valid': True}
+      # Treat failures and errors identically in the JSON
+      # output. Failures are those which cooperatively fail using
+      # Python's unittest APIs; errors are those which abort the test
+      # case early with an execption.
+      failures = []
+      for fail, _ in results.failures + results.errors:
+        # When errors in thrown in individual test method or setUp or tearDown,
+        # fail would be an instance of unittest.TestCase.
+        if isinstance(fail, unittest.TestCase):
+          failures.append(fail.shortName())
+        else:
+          # When errors in thrown in setupClass or tearDownClass, an instance of
+          # _ErrorHolder is is placed in results.errors list. We use the id()
+          # as failure name in this case since shortName() is not available.
+          failures.append(fail.id())
+      failures = sorted(list(failures))
+      for failure_id in failures:
+        json_results['failures'].append(failure_id)
+      for passed_test_case in results.successes:
+        json_results['successes'].append(passed_test_case.shortName())
+      json_results['times'].update(results.times)
+      json.dump(json_results, f)
+  return len(results.failures + results.errors)