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

telemetry/telemetry/testing/run_browser_tests.py

Index: telemetry/telemetry/testing/run_browser_tests.py
diff --git a/telemetry/telemetry/testing/run_browser_tests.py b/telemetry/telemetry/testing/run_browser_tests.py
new file mode 100644
index 0000000000000000000000000000000000000000..6ce835aa1c583d4623b4735fd9abfe31ffe59a62
--- /dev/null
+++ b/telemetry/telemetry/testing/run_browser_tests.py
@@ -0,0 +1,357 @@
+# 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 fnmatch
+import re
+import sys
+import json
+
+from telemetry.core import discover
+from telemetry.internal.browser import browser_options
+from telemetry.internal.platform import android_device
+from telemetry.internal.util import binary_manager
+from telemetry.testing import browser_test_context
+from telemetry.testing import serially_executed_browser_test_case
+
+import typ
+from typ import arg_parser
+
+DEFAULT_LOG_FORMAT = (
+  '(%(levelname)s) %(asctime)s %(module)s.%(funcName)s:%(lineno)d  '
+  '%(message)s')
+
+
+TEST_SUFFIXES = ['*_test.py', '*_tests.py', '*_unittest.py', '*_unittests.py']
+
+
+def ProcessCommandLineOptions(test_class, default_chrome_root, 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.
+  if default_chrome_root:
+    parser.set_defaults(chrome_root=default_chrome_root)
+  finder_options, positional_args = parser.parse_args(args)
+  finder_options.positional_args = positional_args
+  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:
+    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 LoadTestCasesToBeRun(
+    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())]
+
+
+def _CreateTestArgParsers():
+  parser = typ.ArgumentParser(discovery=False, reporting=True, running=True)
+  parser.add_argument('test', type=str, help='Name of the test suite to run')
+  parser.add_argument('--test-filter', type=str, default='', action='store',
+      help='Run only tests whose names match the given filter regexp.')
+  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. '
+        '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')
+
+  parser.add_argument('--default-chrome-root', type=str, default=None)
+  parser.add_argument('--client-config', dest='client_configs',
+                      action='append', default=[])
+  parser.add_argument('--start-dir', dest='start_dirs',
+                      action='append', default=[])
+  parser.add_argument('--skip', metavar='glob', default=[],
+      action='append',
+      help=('Globs of test names to skip (defaults to %(default)s).'))
+  return parser
+
+
+def _SkipMatch(name, skipGlobs):
+  return any(fnmatch.fnmatch(name, glob) for glob in skipGlobs)
+
+
+def _GetClassifier(args):
+  def _SeriallyExecutedBrowserTestCaseClassifer(test_set, test):
+    # Do not pick up tests that do not inherit from
+    # serially_executed_browser_test_case.SeriallyExecutedBrowserTestCase
+    # class.
+    if not isinstance(test,
+        serially_executed_browser_test_case.SeriallyExecutedBrowserTestCase):
+      return
+    name = test.id()
+    if _SkipMatch(name, args.skip):
+      test_set.tests_to_skip.append(
+          typ.TestInput(name, 'skipped because matched --skip'))
+      return
+    # For now, only support running these tests serially.
+    test_set.isolated_tests.append(typ.TestInput(name))
+  return _SeriallyExecutedBrowserTestCaseClassifer
+
+
+def RunTests(args):
+  parser = _CreateTestArgParsers()
+  try:
+    options, extra_args = parser.parse_known_args(args)
+  except arg_parser._Bailout:
+    return parser.exit_status
+  binary_manager.InitDependencyManager(options.client_configs)
+
+  for start_dir in options.start_dirs:
+    modules_to_classes = discover.DiscoverClasses(
+        start_dir, options.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() == options.test:
+      test_class = cl
+      break
+
+  if not test_class:
+    print 'Cannot find test class with name matching %s' % options.test
+    print 'Available tests: %s' % '\n'.join(
+        cl.Name() for cl in browser_test_classes)
+    return 1
+
+  # Create test context.
+  context = browser_test_context.TypTestContext()
+  for c in options.client_configs:
+    context.client_configs.append(c)
+  context.finder_options = ProcessCommandLineOptions(
+      test_class, options.default_chrome_root, extra_args)
+  context.test_class = test_class
+  test_times = None
+  if options.read_abbreviated_json_results_from:
+    with open(options.read_abbreviated_json_results_from, 'r') as f:
+      abbr_results = json.load(f)
+      test_times = abbr_results.get('times')
+  tests_to_run = LoadTestCasesToBeRun(
+      test_class=test_class, finder_options=context.finder_options,
+      filter_regex_str=options.test_filter,
+      filter_tests_after_sharding=options.filter_tests_after_sharding,
+      total_shards=options.total_shards, shard_index=options.shard_index,
+      test_times=test_times,
+      debug_shard_distributions=options.debug_shard_distributions)
+  for t in tests_to_run:
+    context.test_case_ids_to_run.add(t.id())
+  context.Freeze()
+  browser_test_context._global_test_context = context
+
+  # Setup typ runner.
+  runner = typ.Runner()
+
+  runner.context = context
+  runner.setup_fn = _SetUpProcess
+  runner.teardown_fn = _TearDownProcess
+
+  runner.args.jobs = options.jobs
+  runner.args.metadata = options.metadata
+  runner.args.passthrough = options.passthrough
+  runner.args.path = options.path
+  runner.args.retry_limit = options.retry_limit
+  runner.args.test_results_server = options.test_results_server
+  runner.args.test_type = options.test_type
+  runner.args.top_level_dir = options.top_level_dir
+  runner.args.write_full_results_to = options.write_full_results_to
+  runner.args.write_trace_to = options.write_trace_to
+  runner.args.list_only = options.list_only
+  runner.classifier = _GetClassifier(options)
+
+  runner.args.suffixes = TEST_SUFFIXES
+
+  # Since sharding logic is handled by browser_test_runner harness by passing
+  # browser_test_context.test_case_ids_to_run to subprocess to indicate test
+  # cases to be run, we explicitly disable sharding logic in typ.
+  runner.args.total_shards = 1
+  runner.args.shard_index = 0
+
+  runner.args.timing = True
+  runner.args.verbose = options.verbose
+  runner.win_multiprocessing = typ.WinMultiprocessing.importable
+  try:
+    ret, _, _ = runner.run()
+  except KeyboardInterrupt:
+    print >> sys.stderr, "interrupted, exiting"
+    ret = 130
+  return ret
+
+
+def _SetUpProcess(child, context):
+  del child  # Unused.
+  args = context.finder_options
+  if binary_manager.NeedsInit():
+    # On windows, typ doesn't keep the DependencyManager initialization in the
+    # child processes.
+    binary_manager.InitDependencyManager(context.client_configs)
+  if args.remote_platform_options.device == 'android':
+    android_devices = android_device.FindAllAvailableDevices(args)
+    if not android_devices:
+      raise RuntimeError("No Android device found")
+    android_devices.sort(key=lambda device: device.name)
+    args.remote_platform_options.device = (
+        android_devices[child.worker_num-1].guid)
+  browser_test_context._global_test_context = context
+  context.test_class.SetUpProcess()
+
+
+def _TearDownProcess(child, context):
+  del child, context  # Unused.
+  browser_test_context._global_test_context.test_class.TearDownProcess()
+  browser_test_context._global_test_context = None
+
+
+if __name__ == '__main__':
+  ret_code = RunTests(sys.argv[1:])
+  sys.exit(ret_code)