git_test_utils: Automatic commit dates are now in UTC.

testing_support/git_test_utils.py

 # Copyright 2013 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 atexit
 import collections
 import copy
 import datetime
 import hashlib
 import os
@@ skipping 75 matching lines @@
       nxt[1] = prev
 
   def pop(self, last=True):  # pylint: disable=W0221
     if not self:
       raise KeyError('set is empty')
     key = self.end[1][0] if last else self.end[2][0]
     self.discard(key)
     return key
 
 
+class UTC(datetime.tzinfo):
+  """UTC time zone.
+
+  from https://docs.python.org/2/library/datetime.html#tzinfo-objects
+  """
+  def utcoffset(self, dt):
+    return datetime.timedelta(0)
+
+  def tzname(self, dt):
+    return "UTC"
+
+  def dst(self, dt):
+    return datetime.timedelta(0)
+
+
+UTC = UTC()
+
+
 class GitRepoSchema(object):
   """A declarative git testing repo.
 
   Pass a schema to __init__ in the form of:
      A B C D
        B E D
 
   This is the repo
 
      A - B - C - D
@@ skipping 154 matching lines @@
     Automatically creates a temp folder under GitRepo.BASE_TEMP_DIR. It's
     recommended that you clean this repo up by calling nuke() on it, but if not,
     GitRepo will automatically clean up all allocated repos at the exit of the
     program (assuming a normal exit like with sys.exit)
 
     Args:
       schema - An instance of GitRepoSchema
     """
     self.repo_path = tempfile.mkdtemp(dir=self.BASE_TEMP_DIR)
     self.commit_map = {}
-    self._date = datetime.datetime(1970, 1, 1)
+    self._date = datetime.datetime(1970, 1, 1, tzinfo=UTC)
 
     self.to_schema_refs = ['--branches']
 
     self.git('init')
     self.git('config', 'user.name', 'testcase')
     self.git('config', 'user.email', 'testcase@example.com')
     for commit in schema.walk():
       self._add_schema_commit(commit, schema.data_for(commit.name))
       self.last_commit = self[commit.name]
     if schema.master:
@@ skipping 72 matching lines @@
     """Runs a git command specified by |args| in this repo."""
     assert self.repo_path is not None
     try:
       with open(os.devnull, 'wb') as devnull:
         output = subprocess.check_output(
           ('git',) + args, cwd=self.repo_path, stderr=devnull, **kwargs)
       return self.COMMAND_OUTPUT(0, output)
     except subprocess.CalledProcessError as e:
       return self.COMMAND_OUTPUT(e.returncode, e.output)
 
+  def show_commit(self, commit_name, format_string):
+    """Shows a commit (by its schema name) with a given format string."""
+    return self.git('show', '-q', '--pretty=format:%s' % format_string,
+                    self[commit_name]).stdout
+
   def git_commit(self, message):
     return self.git('commit', '-am', message, env=self.get_git_commit_env())
 
   def nuke(self):
     """Obliterates the git repo on disk.
 
     Causes this GitRepo to be unusable.
     """
     shutil.rmtree(self.repo_path)
     self.repo_path = None
@@ skipping 124 matching lines @@
     super(GitRepoReadWriteTestBase, self).setUp()
     self.repo = self.r_schema.reify()
 
   def tearDown(self):
     self.repo.nuke()
     super(GitRepoReadWriteTestBase, self).tearDown()
 
   def assertSchema(self, schema_string):
     self.assertEqual(GitRepoSchema(schema_string).simple_graph(),
                      self.repo.to_schema().simple_graph())