Add lots of utils, PRESUBMIT.py

PRESUBMIT.py

Index: PRESUBMIT.py
diff --git a/PRESUBMIT.py b/PRESUBMIT.py
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+# Copyright (c) 2014 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.
+
+
+"""Presubmit checks for common code."""
+
+import os
+import subprocess
+import sys
+
+
+SKIA_TREE_STATUS_URL = 'http://skia-tree-status.appspot.com'
+SKIP_RUNS_KEYWORD = '(SkipBuildbotRuns)'
+
+
+def _RunPyUnitTests(input_api, output_api):
+  """ Run the Python unit tests and return a list of strings containing any
+  errors.
+  """
+  results = []
+  success = True
+  try:
+    proc = subprocess.Popen(['python', os.path.join('py', 'run_unittests')],
+                            stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
+    success = proc.wait() == 0
+    long_text = proc.communicate()[0]
+  except Exception:
+    success = False
+    long_text = 'Failed to run the common tests!'
+  if not success:
+    results.append(output_api.PresubmitPromptWarning(
+        message='One or more unit tests failed.',
+        long_text=long_text))
+  return results
+
+
+def CheckChange(input_api, output_api):
+  """Presubmit checks for the change on upload or commit.
+
+  The presubmit checks have been handpicked from the list of canned checks
+  here:
+  https://chromium.googlesource.com/chromium/tools/depot_tools/+/master/presubmit_canned_checks.py
+
+  The following are the presubmit checks:
+  * Pylint is run if the change contains any .py files.
+  * Enforces max length for all lines is 80.
+  * Checks that the user didn't add TODO(name) without an owner.
+  * Checks that there is no stray whitespace at source lines end.
+  * Checks that there are no tab characters in any of the text files.
+  """
+  results = []
+
+  pylint_disabled_warnings = (
+      'F0401',  # Unable to import.
+      'E0611',  # No name in module.
+      'W0232',  # Class has no __init__ method.
+      'E1002',  # Use of super on an old style class.
+      'W0403',  # Relative import used.
+      'R0201',  # Method could be a function.
+      'E1003',  # Using class name in super.
+      'W0613',  # Unused argument.
+  )
+  # Run Pylint on only the modified python files. Unfortunately it still runs
+  # Pylint on the whole file instead of just the modified lines.
+  affected_python_files = []
+  for affected_file in input_api.AffectedSourceFiles(None):
+    affected_file_path = affected_file.LocalPath()
+    if affected_file_path.endswith('.py'):
+      affected_python_files.append(affected_file_path)
+  results += input_api.canned_checks.RunPylint(
+      input_api, output_api,
+      disabled_warnings=pylint_disabled_warnings,
+      white_list=affected_python_files)
+
+  # Use 100 for max length for files other than python. Python length is
+  # already checked during the Pylint above.
+  results += input_api.canned_checks.CheckLongLines(input_api, output_api, 100)
+  results += input_api.canned_checks.CheckChangeTodoHasOwner(
+      input_api, output_api)
+  results += input_api.canned_checks.CheckChangeHasNoStrayWhitespace(
+      input_api, output_api)
+  results += input_api.canned_checks.CheckChangeHasNoTabs(input_api, output_api)
+
+  results += _RunPyUnitTests(input_api, output_api)
+
+  return results
+
+
+def _CheckTreeStatus(input_api, output_api, json_url):
+  """Check whether to allow commit.
+
+  Args:
+    input_api: input related apis.
+    output_api: output related apis.
+    json_url: url to download json style status.
+  """
+  results = []
+  tree_status_results = input_api.canned_checks.CheckTreeIsOpen(
+      input_api, output_api, json_url=json_url)
+  display_skip_keyword_prompt = False
+  tree_status = None
+  if not tree_status_results:
+    # Check for caution state only if tree is not closed.
+    connection = input_api.urllib2.urlopen(json_url)
+    status = input_api.json.loads(connection.read())
+    connection.close()
+    tree_status = status['message']
+    if 'caution' in tree_status.lower():
+      # Display a prompt only if we are in an interactive shell. Without this
+      # check the commit queue behaves incorrectly because it considers
+      # prompts to be failures.
+      display_skip_keyword_prompt = True
+  else:
+    # pylint: disable=W0212
+    tree_status = tree_status_results[0]._message
+    display_skip_keyword_prompt = True
+
+  if (display_skip_keyword_prompt
+      and os.isatty(sys.stdout.fileno())
+      and not SKIP_RUNS_KEYWORD in input_api.change.DescriptionText()):
+    long_text = (
+        '%s\nAre you sure the change should be submitted. If it should be '
+        'submitted but not run on the buildbots you can use the %s keyword.' % (
+            tree_status, SKIP_RUNS_KEYWORD))
+    results.append(output_api.PresubmitPromptWarning(
+        message=tree_status, long_text=long_text))
+  return results
+
+
+def CheckChangeOnUpload(input_api, output_api):
+  return CheckChange(input_api, output_api)
+
+
+def CheckChangeOnCommit(input_api, output_api):
+  results = CheckChange(input_api, output_api)
+  results.extend(
+      _CheckTreeStatus(input_api, output_api, json_url=(
+          SKIA_TREE_STATUS_URL + '/banner-status?format=json')))
+  return results
+