depot_tools: Make gclient_scm Python 3 compatible.

Bug: 984182
Change-Id: Ib9c5d2762546f29eaca5eae89b0428431067da4a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/1753029
Auto-Submit: Edward Lesmes <ehmaldonado@chromium.org>
Commit-Queue: Robbie Iannucci <iannucci@chromium.org>
Reviewed-by: Robbie Iannucci <iannucci@chromium.org>
diff --git a/tests/gclient_scm_test.py b/tests/gclient_scm_test.py
index bfb7be7..a9aad58 100755
--- a/tests/gclient_scm_test.py
+++ b/tests/gclient_scm_test.py
@@ -19,10 +19,15 @@
 import tempfile
 import unittest
 
+if sys.version_info.major == 2:
+  from cStringIO import StringIO
+else:
+  from io import StringIO
+
 sys.path.insert(0, os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
 
+from third_party import mock
 from testing_support import fake_repos
-from testing_support.super_mox import mox, StdoutCheck, SuperMoxTestBase
 from testing_support.super_mox import TestCaseUtils
 
 import gclient_scm
@@ -38,73 +43,37 @@
 TIMESTAMP_RE = re.compile('\[[0-9]{1,2}:[0-9]{2}:[0-9]{2}\] (.*)', re.DOTALL)
 def strip_timestamps(value):
   lines = value.splitlines(True)
-  for i in xrange(len(lines)):
+  for i in range(len(lines)):
     m = TIMESTAMP_RE.match(lines[i])
     if m:
       lines[i] = m.group(1)
   return ''.join(lines)
 
 
-class GCBaseTestCase(object):
-  def assertRaisesError(self, msg, fn, *args, **kwargs):
-    """Like unittest's assertRaises() but checks for Gclient.Error."""
-    try:
-      fn(*args, **kwargs)
-    except gclient_scm.gclient_utils.Error as e:
-      self.assertEquals(e.args[0], msg)
-    else:
-      self.fail('%s not raised' % msg)
-
-
-class BaseTestCase(GCBaseTestCase, SuperMoxTestBase):
-  def setUp(self):
-    SuperMoxTestBase.setUp(self)
-    self.mox.StubOutWithMock(gclient_scm.gclient_utils, 'CheckCallAndFilter')
-    self.mox.StubOutWithMock(gclient_scm.gclient_utils, 'FileRead')
-    self.mox.StubOutWithMock(gclient_scm.gclient_utils, 'FileWrite')
-    self.mox.StubOutWithMock(gclient_scm.gclient_utils, 'rmtree')
-    self.mox.StubOutWithMock(subprocess2, 'communicate')
-    self.mox.StubOutWithMock(subprocess2, 'Popen')
-    self._scm_wrapper = gclient_scm.GitWrapper
-    self._original_GitBinaryExists = gclient_scm.GitWrapper.BinaryExists
-    gclient_scm.GitWrapper.BinaryExists = staticmethod(lambda : True)
-    # Absolute path of the fake checkout directory.
-    self.base_path = join(self.root_dir, self.relpath)
-
-  def tearDown(self):
-    SuperMoxTestBase.tearDown(self)
-    gclient_scm.GitWrapper.BinaryExists = self._original_GitBinaryExists
-
-
-class BasicTests(SuperMoxTestBase):
-  def setUp(self):
-    SuperMoxTestBase.setUp(self)
-
-  def testGetFirstRemoteUrl(self):
+class BasicTests(unittest.TestCase):
+  @mock.patch('gclient_scm.scm.GIT.Capture')
+  def testGetFirstRemoteUrl(self, mockCapture):
     REMOTE_STRINGS = [('remote.origin.url E:\\foo\\bar', 'E:\\foo\\bar'),
                       ('remote.origin.url /b/foo/bar', '/b/foo/bar'),
                       ('remote.origin.url https://foo/bar', 'https://foo/bar'),
                       ('remote.origin.url E:\\Fo Bar\\bax', 'E:\\Fo Bar\\bax'),
                       ('remote.origin.url git://what/"do', 'git://what/"do')]
     FAKE_PATH = '/fake/path'
-    self.mox.StubOutWithMock(gclient_scm.scm.GIT, 'Capture')
-    for question, _ in REMOTE_STRINGS:
-      gclient_scm.scm.GIT.Capture(
-          ['config', '--local', '--get-regexp', r'remote.*.url'],
-          cwd=FAKE_PATH).AndReturn(question)
-
-    self.mox.ReplayAll()
+    mockCapture.side_effect = [question for question, _ in REMOTE_STRINGS]
 
     for _, answer in REMOTE_STRINGS:
-      self.assertEquals(gclient_scm.SCMWrapper._get_first_remote_url(FAKE_PATH),
-                        answer)
+      self.assertEqual(
+          gclient_scm.SCMWrapper._get_first_remote_url(FAKE_PATH), answer)
 
-  def tearDown(self):
-    SuperMoxTestBase.tearDown(self)
+    expected_calls = [
+        mock.call(['config', '--local', '--get-regexp', r'remote.*.url'],
+                   cwd=FAKE_PATH)
+        for _ in REMOTE_STRINGS
+    ]
+    self.assertEqual(mockCapture.mock_calls, expected_calls)
 
 
-class BaseGitWrapperTestCase(GCBaseTestCase, StdoutCheck, TestCaseUtils,
-                             unittest.TestCase):
+class BaseGitWrapperTestCase(unittest.TestCase, TestCaseUtils):
   """This class doesn't use pymox."""
   class OptionsObject(object):
     def __init__(self, verbose=False, revision=None):
@@ -193,7 +162,7 @@
     value = sys.stdout.getvalue()
     sys.stdout.close()
     # pylint: disable=no-member
-    self.assertEquals(expected, strip_timestamps(value))
+    self.assertEqual(expected, strip_timestamps(value))
 
   @staticmethod
   def CreateGitRepo(git_import, path):
@@ -205,7 +174,7 @@
       # git is not available, skip this test.
       return False
     Popen(['git', 'fast-import', '--quiet'], stdin=PIPE, stdout=PIPE,
-        stderr=STDOUT, cwd=path).communicate(input=git_import)
+        stderr=STDOUT, cwd=path).communicate(input=git_import.encode())
     Popen(['git', 'checkout', '-q'], stdout=PIPE, stderr=STDOUT,
         cwd=path).communicate()
     Popen(['git', 'remote', 'add', '-f', 'origin', '.'], stdout=PIPE,
@@ -224,13 +193,13 @@
 
   def _GetAskForDataCallback(self, expected_prompt, return_value):
     def AskForData(prompt, options):
-      self.assertEquals(prompt, expected_prompt)
+      self.assertEqual(prompt, expected_prompt)
       return return_value
     return AskForData
 
   def setUp(self):
-    TestCaseUtils.setUp(self)
     unittest.TestCase.setUp(self)
+    TestCaseUtils.setUp(self)
     self.url = 'git://foo'
     # The .git suffix allows gclient_scm to recognize the dir as a git repo
     # when cloning it locally
@@ -238,19 +207,12 @@
     self.relpath = '.'
     self.base_path = join(self.root_dir, self.relpath)
     self.enabled = self.CreateGitRepo(self.sample_git_import, self.base_path)
-    StdoutCheck.setUp(self)
     self._original_GitBinaryExists = gclient_scm.GitWrapper.BinaryExists
-    gclient_scm.GitWrapper.BinaryExists = staticmethod(lambda : True)
-
-  def tearDown(self):
-    try:
-      rmtree(self.root_dir)
-      StdoutCheck.tearDown(self)
-      TestCaseUtils.tearDown(self)
-      unittest.TestCase.tearDown(self)
-    finally:
-      # TODO(maruel): Use auto_stub.TestCase.
-      gclient_scm.GitWrapper.BinaryExists = self._original_GitBinaryExists
+    mock.patch('gclient_scm.GitWrapper.BinaryExists',
+               staticmethod(lambda : True)).start()
+    mock.patch('sys.stdout', StringIO()).start()
+    self.addCleanup(mock.patch.stopall)
+    self.addCleanup(lambda: rmtree(self.root_dir))
 
 
 class ManagedGitWrapperTestCase(BaseGitWrapperTestCase):
@@ -267,10 +229,10 @@
     gclient_scm.os.remove(file_path)
     file_list = []
     scm.revert(options, self.args, file_list)
-    self.assertEquals(file_list, [file_path])
+    self.assertEqual(file_list, [file_path])
     file_list = []
     scm.diff(options, self.args, file_list)
-    self.assertEquals(file_list, [])
+    self.assertEqual(file_list, [])
     sys.stdout.close()
 
   def testRevertNone(self):
@@ -283,9 +245,9 @@
     scm.update(options, None, file_list)
     file_list = []
     scm.revert(options, self.args, file_list)
-    self.assertEquals(file_list, [])
-    self.assertEquals(scm.revinfo(options, self.args, None),
-                      'a7142dc9f0009350b96a11f372b6ea658592aa95')
+    self.assertEqual(file_list, [])
+    self.assertEqual(scm.revinfo(options, self.args, None),
+                     'a7142dc9f0009350b96a11f372b6ea658592aa95')
     sys.stdout.close()
 
   def testRevertModified(self):
@@ -297,14 +259,15 @@
     file_list = []
     scm.update(options, None, file_list)
     file_path = join(self.base_path, 'a')
-    open(file_path, 'a').writelines('touched\n')
+    with open(file_path, 'a') as f:
+      f.writelines('touched\n')
     file_list = []
     scm.revert(options, self.args, file_list)
-    self.assertEquals(file_list, [file_path])
+    self.assertEqual(file_list, [file_path])
     file_list = []
     scm.diff(options, self.args, file_list)
-    self.assertEquals(file_list, [])
-    self.assertEquals(scm.revinfo(options, self.args, None),
+    self.assertEqual(file_list, [])
+    self.assertEqual(scm.revinfo(options, self.args, None),
                       'a7142dc9f0009350b96a11f372b6ea658592aa95')
     sys.stdout.close()
 
@@ -317,19 +280,18 @@
     file_list = []
     scm.update(options, None, file_list)
     file_path = join(self.base_path, 'c')
-    f = open(file_path, 'w')
-    f.writelines('new\n')
-    f.close()
+    with open(file_path, 'w') as f:
+      f.writelines('new\n')
     Popen(['git', 'add', 'c'], stdout=PIPE,
           stderr=STDOUT, cwd=self.base_path).communicate()
     file_list = []
     scm.revert(options, self.args, file_list)
-    self.assertEquals(file_list, [file_path])
+    self.assertEqual(file_list, [file_path])
     file_list = []
     scm.diff(options, self.args, file_list)
-    self.assertEquals(file_list, [])
-    self.assertEquals(scm.revinfo(options, self.args, None),
-                      'a7142dc9f0009350b96a11f372b6ea658592aa95')
+    self.assertEqual(file_list, [])
+    self.assertEqual(scm.revinfo(options, self.args, None),
+                     'a7142dc9f0009350b96a11f372b6ea658592aa95')
     sys.stdout.close()
 
   def testStatusNew(self):
@@ -337,12 +299,13 @@
       return
     options = self.Options()
     file_path = join(self.base_path, 'a')
-    open(file_path, 'a').writelines('touched\n')
+    with open(file_path, 'a') as f:
+      f.writelines('touched\n')
     scm = gclient_scm.GitWrapper(self.url, self.root_dir,
                                  self.relpath)
     file_list = []
     scm.status(options, self.args, file_list)
-    self.assertEquals(file_list, [file_path])
+    self.assertEqual(file_list, [file_path])
     self.checkstdout(
         ('\n________ running \'git -c core.quotePath=false diff --name-status '
          '069c602044c5388d2d15c3f875b057c852003458\' in \'%s\'\n\nM\ta\n') %
@@ -355,14 +318,15 @@
     expected_file_list = []
     for f in ['a', 'b']:
       file_path = join(self.base_path, f)
-      open(file_path, 'a').writelines('touched\n')
+      with open(file_path, 'a') as f:
+        f.writelines('touched\n')
       expected_file_list.extend([file_path])
     scm = gclient_scm.GitWrapper(self.url, self.root_dir,
                                  self.relpath)
     file_list = []
     scm.status(options, self.args, file_list)
     expected_file_list = [join(self.base_path, x) for x in ['a', 'b']]
-    self.assertEquals(sorted(file_list), expected_file_list)
+    self.assertEqual(sorted(file_list), expected_file_list)
     self.checkstdout(
         ('\n________ running \'git -c core.quotePath=false diff --name-status '
          '069c602044c5388d2d15c3f875b057c852003458\' in \'%s\'\n\nM\ta\nM\tb\n')
@@ -377,8 +341,8 @@
                                  self.relpath)
     file_list = []
     scm.update(options, (), file_list)
-    self.assertEquals(file_list, expected_file_list)
-    self.assertEquals(scm.revinfo(options, (), None),
+    self.assertEqual(file_list, expected_file_list)
+    self.assertEqual(scm.revinfo(options, (), None),
                       'a7142dc9f0009350b96a11f372b6ea658592aa95')
     sys.stdout.close()
 
@@ -393,15 +357,15 @@
     rev = scm.revinfo(options, (), None)
     file_list = []
     scm.update(options, (), file_list)
-    self.assertEquals(file_list, [join(self.base_path, x)
-                                  for x in ['a', 'b', 'c']])
+    self.assertEqual(file_list, [join(self.base_path, x)
+                                 for x in ['a', 'b', 'c']])
     # The actual commit that is created is unstable, so we verify its tree and
     # parents instead.
-    self.assertEquals(scm._Capture(['rev-parse', 'HEAD:']),
-                      'd2e35c10ac24d6c621e14a1fcadceb533155627d')
-    self.assertEquals(scm._Capture(['rev-parse', 'HEAD^1']), rev)
-    self.assertEquals(scm._Capture(['rev-parse', 'HEAD^2']),
-                      scm._Capture(['rev-parse', 'origin/master']))
+    self.assertEqual(scm._Capture(['rev-parse', 'HEAD:']),
+                     'd2e35c10ac24d6c621e14a1fcadceb533155627d')
+    self.assertEqual(scm._Capture(['rev-parse', 'HEAD^1']), rev)
+    self.assertEqual(scm._Capture(['rev-parse', 'HEAD^2']),
+                     scm._Capture(['rev-parse', 'origin/master']))
     sys.stdout.close()
 
   def testUpdateRebase(self):
@@ -417,14 +381,14 @@
         'Cannot fast-forward merge, attempt to rebase? '
         '(y)es / (q)uit / (s)kip : ', 'y')
     scm.update(options, (), file_list)
-    self.assertEquals(file_list, [join(self.base_path, x)
-                                  for x in ['a', 'b', 'c']])
+    self.assertEqual(file_list, [join(self.base_path, x)
+                                 for x in ['a', 'b', 'c']])
     # The actual commit that is created is unstable, so we verify its tree and
     # parent instead.
-    self.assertEquals(scm._Capture(['rev-parse', 'HEAD:']),
-                      'd2e35c10ac24d6c621e14a1fcadceb533155627d')
-    self.assertEquals(scm._Capture(['rev-parse', 'HEAD^']),
-                      scm._Capture(['rev-parse', 'origin/master']))
+    self.assertEqual(scm._Capture(['rev-parse', 'HEAD:']),
+                     'd2e35c10ac24d6c621e14a1fcadceb533155627d')
+    self.assertEqual(scm._Capture(['rev-parse', 'HEAD^']),
+                     scm._Capture(['rev-parse', 'origin/master']))
     sys.stdout.close()
 
   def testUpdateReset(self):
@@ -435,10 +399,12 @@
 
     dir_path = join(self.base_path, 'c')
     os.mkdir(dir_path)
-    open(join(dir_path, 'nested'), 'w').writelines('new\n')
+    with open(join(dir_path, 'nested'), 'w') as f:
+      f.writelines('new\n')
 
     file_path = join(self.base_path, 'file')
-    open(file_path, 'w').writelines('new\n')
+    with open(file_path, 'w') as f:
+      f.writelines('new\n')
 
     scm = gclient_scm.GitWrapper(self.url, self.root_dir,
                                  self.relpath)
@@ -461,8 +427,8 @@
 
     file_list = []
     scm.update(options, (), file_list)
-    self.assertEquals(scm.revinfo(options, (), None),
-                      '069c602044c5388d2d15c3f875b057c852003458')
+    self.assertEqual(scm.revinfo(options, (), None),
+                     '069c602044c5388d2d15c3f875b057c852003458')
     sys.stdout.close()
 
   def testUpdateResetDeleteUnversionedTrees(self):
@@ -474,10 +440,12 @@
 
     dir_path = join(self.base_path, 'dir')
     os.mkdir(dir_path)
-    open(join(dir_path, 'nested'), 'w').writelines('new\n')
+    with open(join(dir_path, 'nested'), 'w') as f:
+      f.writelines('new\n')
 
     file_path = join(self.base_path, 'file')
-    open(file_path, 'w').writelines('new\n')
+    with open(file_path, 'w') as f:
+      f.writelines('new\n')
 
     scm = gclient_scm.GitWrapper(self.url, self.root_dir,
                                  self.relpath)
@@ -494,7 +462,8 @@
     scm = gclient_scm.GitWrapper(self.url, self.root_dir,
                                  self.relpath)
     file_path = join(self.base_path, 'b')
-    open(file_path, 'w').writelines('conflict\n')
+    with open(file_path, 'w') as f:
+      f.writelines('conflict\n')
     try:
       scm.update(options, (), [])
       self.fail()
@@ -544,19 +513,29 @@
     scm = gclient_scm.GitWrapper(self.url, self.root_dir,
                                  self.relpath)
     file_path = join(self.base_path, 'b')
-    open(file_path, 'w').writelines('conflict\n')
+    with open(file_path, 'w') as f:
+      f.writelines('conflict\n')
     scm._Run(['commit', '-am', 'test'], options)
     scm._AskForData = self._GetAskForDataCallback(
         'Cannot fast-forward merge, attempt to rebase? '
         '(y)es / (q)uit / (s)kip : ', 'y')
-    exception = ('Conflict while rebasing this branch.\n'
-                 'Fix the conflict and run gclient again.\n'
-                 'See \'man git-rebase\' for details.\n')
-    self.assertRaisesError(exception, scm.update, options, (), [])
-    exception = ('\n____ . at refs/remotes/origin/master\n'
-                 '\tYou have unstaged changes.\n'
-                 '\tPlease commit, stash, or reset.\n')
-    self.assertRaisesError(exception, scm.update, options, (), [])
+
+    with self.assertRaises(gclient_scm.gclient_utils.Error) as e:
+      scm.update(options, (), [])
+    self.assertEqual(
+        e.exception.args[0],
+        'Conflict while rebasing this branch.\n'
+        'Fix the conflict and run gclient again.\n'
+        'See \'man git-rebase\' for details.\n')
+
+    with self.assertRaises(gclient_scm.gclient_utils.Error) as e:
+      scm.update(options, (), [])
+    self.assertEqual(
+        e.exception.args[0],
+        '\n____ . at refs/remotes/origin/master\n'
+        '\tYou have unstaged changes.\n'
+        '\tPlease commit, stash, or reset.\n')
+
     sys.stdout.close()
 
   def testRevinfo(self):
@@ -566,7 +545,7 @@
     scm = gclient_scm.GitWrapper(self.url, self.root_dir,
                                  self.relpath)
     rev_info = scm.revinfo(options, (), None)
-    self.assertEquals(rev_info, '069c602044c5388d2d15c3f875b057c852003458')
+    self.assertEqual(rev_info, '069c602044c5388d2d15c3f875b057c852003458')
 
   def testMirrorPushUrl(self):
     if not self.enabled:
@@ -600,11 +579,11 @@
             '  fetch_url: %s' % fetch_url,
             '  mirror:    %s' % mirror]))
     push_url = scm._Capture(['remote', 'get-url', '--push', 'origin'])
-    self.assertEquals(push_url, self.url)
+    self.assertEqual(push_url, self.url)
     sys.stdout.close()
 
 
-class ManagedGitWrapperTestCaseMox(BaseTestCase):
+class ManagedGitWrapperTestCaseMock(unittest.TestCase):
   class OptionsObject(object):
     def __init__(self, verbose=False, revision=None, force=False):
       self.verbose = verbose
@@ -627,10 +606,9 @@
     value = sys.stdout.getvalue()
     sys.stdout.close()
     # pylint: disable=no-member
-    self.assertEquals(expected, strip_timestamps(value))
+    self.assertEqual(expected, strip_timestamps(value))
 
   def setUp(self):
-    BaseTestCase.setUp(self)
     self.fake_hash_1 = 't0ta11yf4k3'
     self.fake_hash_2 = '3v3nf4k3r'
     self.url = 'git://foo'
@@ -639,107 +617,94 @@
     self.base_path = os.path.join(self.root_dir, self.relpath)
     self.backup_base_path = os.path.join(self.root_dir,
                                          'old_%s.git' % self.relpath)
+    mock.patch('gclient_scm.scm.GIT.ApplyEnvVars').start()
+    mock.patch('gclient_scm.GitWrapper._CheckMinVersion').start()
+    mock.patch('gclient_scm.GitWrapper._Fetch').start()
+    mock.patch('gclient_scm.GitWrapper._DeleteOrMove').start()
+    mock.patch('sys.stdout', StringIO()).start()
+    self.addCleanup(mock.patch.stopall)
 
-  def tearDown(self):
-    BaseTestCase.tearDown(self)
-
-  def testGetUsableRevGit(self):
+  @mock.patch('scm.GIT.IsValidRevision')
+  @mock.patch('os.path.isdir', lambda _: True)
+  def testGetUsableRevGit(self, mockIsValidRevision):
     # pylint: disable=no-member
     options = self.Options(verbose=True)
 
-    self.mox.StubOutWithMock(gclient_scm.scm.GIT, 'IsValidRevision', True)
-    gclient_scm.scm.GIT.IsValidRevision(cwd=self.base_path, rev=self.fake_hash_1
-        ).AndReturn(True)
-    gclient_scm.scm.GIT.IsValidRevision(cwd=self.base_path, rev='1'
-        ).AndReturn(False)
-    gclient_scm.scm.GIT.IsValidRevision(cwd=self.base_path, rev='1'
-        ).AndReturn(False)
-
-    self.mox.StubOutWithMock(gclient_scm.GitWrapper, '_Fetch', True)
-    # pylint: disable=no-value-for-parameter
-    gclient_scm.GitWrapper._Fetch(options).AndReturn(None)
-
-    gclient_scm.scm.os.path.isdir(self.base_path).AndReturn(True)
-    gclient_scm.os.path.isdir(self.base_path).AndReturn(True)
-
-    self.mox.ReplayAll()
+    mockIsValidRevision.side_effect = lambda cwd, rev: rev != '1'
 
     git_scm = gclient_scm.GitWrapper(self.url, self.root_dir,
                                      self.relpath)
     # A [fake] git sha1 with a git repo should work (this is in the case that
     # the LKGR gets flipped to git sha1's some day).
-    self.assertEquals(git_scm.GetUsableRev(self.fake_hash_1, options),
-                      self.fake_hash_1)
+    self.assertEqual(git_scm.GetUsableRev(self.fake_hash_1, options),
+                     self.fake_hash_1)
     # An SVN rev with an existing purely git repo should raise an exception.
     self.assertRaises(gclient_scm.gclient_utils.Error,
                       git_scm.GetUsableRev, '1', options)
 
-  def testUpdateNoDotGit(self):
+  @mock.patch('gclient_scm.GitWrapper._Clone')
+  @mock.patch('os.path.isdir')
+  @mock.patch('os.path.exists')
+  @mock.patch('subprocess2.check_output')
+  def testUpdateNoDotGit(
+      self, mockCheckOutput, mockExists, mockIsdir, mockClone):
+    mockIsdir.side_effect = lambda path: path == self.base_path
+    mockExists.side_effect = lambda path: path == self.base_path
+    mockCheckOutput.return_value = b''
+
     options = self.Options()
-
-    gclient_scm.os.path.isdir(
-        os.path.join(self.base_path, '.git', 'hooks')).AndReturn(False)
-    gclient_scm.os.path.exists(self.backup_base_path).AndReturn(False)
-    gclient_scm.os.path.exists(self.base_path).AndReturn(True)
-    gclient_scm.os.path.isdir(self.base_path).AndReturn(True)
-    gclient_scm.os.path.exists(os.path.join(self.base_path, '.git')
-                               ).AndReturn(False)
-    self.mox.StubOutWithMock(gclient_scm.GitWrapper, '_Clone', True)
-    # pylint: disable=no-value-for-parameter
-    gclient_scm.GitWrapper._Clone('refs/remotes/origin/master', self.url,
-                                  options)
-    self.mox.StubOutWithMock(gclient_scm.subprocess2, 'check_output', True)
-    gclient_scm.subprocess2.check_output(
-        ['git', '-c', 'core.quotePath=false', 'ls-files'], cwd=self.base_path,
-        env=gclient_scm.scm.GIT.ApplyEnvVars({}), stderr=-1,).AndReturn('')
-    gclient_scm.subprocess2.check_output(
-        ['git', 'rev-parse', '--verify', 'HEAD'],
-        cwd=self.base_path,
-        env=gclient_scm.scm.GIT.ApplyEnvVars({}),
-        stderr=-1,
-        ).AndReturn('')
-
-    self.mox.ReplayAll()
-    scm = self._scm_wrapper(self.url, self.root_dir,
-                            self.relpath)
+    scm = gclient_scm.GitWrapper(
+        self.url, self.root_dir, self.relpath)
     scm.update(options, None, [])
+
+    env = gclient_scm.scm.GIT.ApplyEnvVars({})
+    self.assertEqual(
+        mockCheckOutput.mock_calls,
+        [
+            mock.call(
+                ['git', '-c', 'core.quotePath=false', 'ls-files'],
+                cwd=self.base_path, env=env, stderr=-1),
+            mock.call(
+                ['git', 'rev-parse', '--verify', 'HEAD'],
+                cwd=self.base_path, env=env, stderr=-1),
+        ])
+    mockClone.assert_called_with(
+        'refs/remotes/origin/master', self.url, options)
     self.checkstdout('\n')
 
-  def testUpdateConflict(self):
+  @mock.patch('gclient_scm.GitWrapper._Clone')
+  @mock.patch('os.path.isdir')
+  @mock.patch('os.path.exists')
+  @mock.patch('subprocess2.check_output')
+  def testUpdateConflict(
+      self, mockCheckOutput, mockExists, mockIsdir, mockClone):
+    mockIsdir.side_effect = lambda path: path == self.base_path
+    mockExists.side_effect = lambda path: path == self.base_path
+    mockCheckOutput.return_value = b''
+    mockClone.side_effect = [
+        gclient_scm.subprocess2.CalledProcessError(
+            None, None, None, None, None),
+        None,
+    ]
+
     options = self.Options()
-
-    gclient_scm.os.path.isdir(
-        os.path.join(self.base_path, '.git', 'hooks')).AndReturn(False)
-    gclient_scm.os.path.exists(self.backup_base_path).AndReturn(False)
-    gclient_scm.os.path.exists(self.base_path).AndReturn(True)
-    gclient_scm.os.path.isdir(self.base_path).AndReturn(True)
-    gclient_scm.os.path.exists(os.path.join(self.base_path, '.git')
-                               ).AndReturn(False)
-    self.mox.StubOutWithMock(gclient_scm.GitWrapper, '_Clone', True)
-    # pylint: disable=no-value-for-parameter
-    gclient_scm.GitWrapper._Clone(
-        'refs/remotes/origin/master', self.url, options
-    ).AndRaise(gclient_scm.subprocess2.CalledProcessError(None, None, None,
-                                                          None, None))
-    self.mox.StubOutWithMock(gclient_scm.GitWrapper, '_DeleteOrMove', True)
-    gclient_scm.GitWrapper._DeleteOrMove(False)
-    gclient_scm.GitWrapper._Clone('refs/remotes/origin/master', self.url,
-                                  options)
-    self.mox.StubOutWithMock(gclient_scm.subprocess2, 'check_output', True)
-    gclient_scm.subprocess2.check_output(
-        ['git', '-c', 'core.quotePath=false', 'ls-files'], cwd=self.base_path,
-        env=gclient_scm.scm.GIT.ApplyEnvVars({}), stderr=-1,).AndReturn('')
-    gclient_scm.subprocess2.check_output(
-        ['git', 'rev-parse', '--verify', 'HEAD'],
-        cwd=self.base_path,
-        env=gclient_scm.scm.GIT.ApplyEnvVars({}),
-        stderr=-1,
-        ).AndReturn('')
-
-    self.mox.ReplayAll()
-    scm = self._scm_wrapper(self.url, self.root_dir,
+    scm = gclient_scm.GitWrapper(self.url, self.root_dir,
                             self.relpath)
     scm.update(options, None, [])
+
+    env = gclient_scm.scm.GIT.ApplyEnvVars({})
+    self.assertEqual(
+        mockCheckOutput.mock_calls,
+        [
+            mock.call(
+                ['git', '-c', 'core.quotePath=false', 'ls-files'],
+                cwd=self.base_path, env=env, stderr=-1),
+            mock.call(
+                ['git', 'rev-parse', '--verify', 'HEAD'],
+                cwd=self.base_path, env=env, stderr=-1),
+        ])
+    mockClone.assert_called_with(
+        'refs/remotes/origin/master', self.url, options)
     self.checkstdout('\n')
 
 
@@ -784,11 +749,11 @@
     options.revision = 'unmanaged'
     scm.update(options, (), file_list)
 
-    self.assertEquals(file_list, expected_file_list)
-    self.assertEquals(scm.revinfo(options, (), None),
-                      '069c602044c5388d2d15c3f875b057c852003458')
+    self.assertEqual(file_list, expected_file_list)
+    self.assertEqual(scm.revinfo(options, (), None),
+                     '069c602044c5388d2d15c3f875b057c852003458')
     # indicates detached HEAD
-    self.assertEquals(self.getCurrentBranch(), None)
+    self.assertEqual(self.getCurrentBranch(), None)
     self.checkInStdout(
       'Checked out refs/remotes/origin/master to a detached HEAD')
 
@@ -816,11 +781,11 @@
     options.revision = 'unmanaged'
     scm.update(options, (), file_list)
 
-    self.assertEquals(file_list, expected_file_list)
-    self.assertEquals(scm.revinfo(options, (), None),
-                      'a7142dc9f0009350b96a11f372b6ea658592aa95')
+    self.assertEqual(file_list, expected_file_list)
+    self.assertEqual(scm.revinfo(options, (), None),
+                     'a7142dc9f0009350b96a11f372b6ea658592aa95')
     # indicates detached HEAD
-    self.assertEquals(self.getCurrentBranch(), None)
+    self.assertEqual(self.getCurrentBranch(), None)
     self.checkInStdout(
       'Checked out a7142dc9f0009350b96a11f372b6ea658592aa95 to a detached HEAD')
 
@@ -848,11 +813,11 @@
     options.revision = 'unmanaged'
     scm.update(options, (), file_list)
 
-    self.assertEquals(file_list, expected_file_list)
-    self.assertEquals(scm.revinfo(options, (), None),
-                      '9a51244740b25fa2ded5252ca00a3178d3f665a9')
+    self.assertEqual(file_list, expected_file_list)
+    self.assertEqual(scm.revinfo(options, (), None),
+                     '9a51244740b25fa2ded5252ca00a3178d3f665a9')
     # indicates detached HEAD
-    self.assertEquals(self.getCurrentBranch(), None)
+    self.assertEqual(self.getCurrentBranch(), None)
     self.checkInStdout(
         'Checked out 9a51244740b25fa2ded5252ca00a3178d3f665a9 '
         'to a detached HEAD')
@@ -881,11 +846,11 @@
     options.revision = 'unmanaged'
     scm.update(options, (), file_list)
 
-    self.assertEquals(file_list, expected_file_list)
-    self.assertEquals(scm.revinfo(options, (), None),
-                      '9a51244740b25fa2ded5252ca00a3178d3f665a9')
+    self.assertEqual(file_list, expected_file_list)
+    self.assertEqual(scm.revinfo(options, (), None),
+                     '9a51244740b25fa2ded5252ca00a3178d3f665a9')
     # indicates detached HEAD
-    self.assertEquals(self.getCurrentBranch(), None)
+    self.assertEqual(self.getCurrentBranch(), None)
     self.checkInStdout(
       'Checked out refs/remotes/origin/feature to a detached HEAD')
 
@@ -913,9 +878,9 @@
     options.revision = 'unmanaged'
     scm.update(options, (), file_list)
 
-    self.assertEquals(file_list, expected_file_list)
-    self.assertEquals(scm.revinfo(options, (), None),
-                      '9a51244740b25fa2ded5252ca00a3178d3f665a9')
+    self.assertEqual(file_list, expected_file_list)
+    self.assertEqual(scm.revinfo(options, (), None),
+                     '9a51244740b25fa2ded5252ca00a3178d3f665a9')
     # @refs/heads/feature is AKA @refs/remotes/origin/feature in the clone, so
     # should be treated as such by gclient.
     # TODO(mmoss): Though really, we should only allow DEPS to specify branches
@@ -924,7 +889,7 @@
     # defaults at some point). But that will take more work to stop using
     # refs/remotes/ everywhere that we do (and to stop assuming a DEPS ref will
     # always resolve locally, like when passing them to show-ref or rev-list).
-    self.assertEquals(self.getCurrentBranch(), None)
+    self.assertEqual(self.getCurrentBranch(), None)
     self.checkInStdout(
       'Checked out refs/remotes/origin/feature to a detached HEAD')
 
@@ -940,19 +905,18 @@
     file_list = []
     options.revision = 'unmanaged'
     scm.update(options, (), file_list)
-    self.assertEquals(file_list, expected_file_list)
-    self.assertEquals(scm.revinfo(options, (), None),
-                      '069c602044c5388d2d15c3f875b057c852003458')
+    self.assertEqual(file_list, expected_file_list)
+    self.assertEqual(scm.revinfo(options, (), None),
+                     '069c602044c5388d2d15c3f875b057c852003458')
     self.checkstdout('________ unmanaged solution; skipping .\n')
 
 
-class CipdWrapperTestCase(BaseTestCase):
+class CipdWrapperTestCase(unittest.TestCase):
 
   def setUp(self):
     # Create this before setting up mocks.
     self._cipd_root_dir = tempfile.mkdtemp()
     self._workdir = tempfile.mkdtemp()
-    BaseTestCase.setUp(self)
 
     self._cipd_instance_url = 'https://chrome-infra-packages.appspot.com'
     self._cipd_root = gclient_scm.CipdRoot(
@@ -963,12 +927,13 @@
         self._cipd_root.add_package('b', 'bar_package', 'bar_version'),
         self._cipd_root.add_package('b', 'baz_package', 'baz_version'),
     ]
-    self.mox.StubOutWithMock(self._cipd_root, 'add_package')
-    self.mox.StubOutWithMock(self._cipd_root, 'clobber')
-    self.mox.StubOutWithMock(self._cipd_root, 'ensure')
+    mock.patch('tempfile.mkdtemp', lambda: self._workdir).start()
+    mock.patch('gclient_scm.CipdRoot.add_package').start()
+    mock.patch('gclient_scm.CipdRoot.clobber').start()
+    mock.patch('gclient_scm.CipdRoot.ensure').start()
+    self.addCleanup(mock.patch.stopall)
 
   def tearDown(self):
-    BaseTestCase.tearDown(self)
     rmtree(self._cipd_root_dir)
     rmtree(self._workdir)
 
@@ -989,14 +954,12 @@
 
   def testRevert(self):
     """Checks that revert does nothing."""
-    scm = self.createScmWithPackageThatSatisfies(
-        lambda _: True)
-
-    self.mox.ReplayAll()
-
+    scm = self.createScmWithPackageThatSatisfies(lambda _: True)
     scm.revert(None, (), [])
 
-  def testRevinfo(self):
+  @mock.patch('gclient_scm.gclient_utils.CheckCallAndFilter')
+  @mock.patch('gclient_scm.gclient_utils.rmtree')
+  def testRevinfo(self, mockRmtree, mockCheckCallAndFilter):
     """Checks that revinfo uses the JSON from cipd describe."""
     scm = self.createScmWithPackageThatSatisfies(lambda _: True)
 
@@ -1012,31 +975,20 @@
     with open(describe_json_path, 'w') as describe_json:
       json.dump(json_contents, describe_json)
 
-    cmd = [
+    revinfo = scm.revinfo(None, (), [])
+    self.assertEqual(revinfo, expected_revinfo)
+
+    mockRmtree.assert_called_with(self._workdir)
+    mockCheckCallAndFilter.assert_called_with([
         'cipd', 'describe', 'foo_package',
         '-log-level', 'error',
         '-version', 'foo_version',
         '-json-output', describe_json_path,
-    ]
-
-    self.mox.StubOutWithMock(tempfile, 'mkdtemp')
-
-    tempfile.mkdtemp().AndReturn(self._workdir)
-    gclient_scm.gclient_utils.CheckCallAndFilter(cmd)
-    gclient_scm.gclient_utils.rmtree(self._workdir)
-
-    self.mox.ReplayAll()
-
-    revinfo = scm.revinfo(None, (), [])
-    self.assertEquals(revinfo, expected_revinfo)
+    ])
 
   def testUpdate(self):
     """Checks that update does nothing."""
-    scm = self.createScmWithPackageThatSatisfies(
-        lambda _: True)
-
-    self.mox.ReplayAll()
-
+    scm = self.createScmWithPackageThatSatisfies(lambda _: True)
     scm.update(None, (), [])
 
 
@@ -1327,7 +1279,7 @@
           self.url, 'refs/changes/36/1236/1', 'refs/heads/master', self.options,
           file_list)
     self.assertEqual(cm.exception.cmd[:2], ['git', 'cherry-pick'])
-    self.assertIn('error: could not apply', cm.exception.stderr)
+    self.assertIn(b'error: could not apply', cm.exception.stderr)
 
     # Try to apply 'refs/changes/35/1235/1', which doesn't have a merge
     # conflict.