Move auto_stub.py from commit-queue

tests/subprocess2_test.py

 #!/usr/bin/env python
 # Copyright (c) 2011 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.
 
 """Unit tests for subprocess2.py."""
 
 import logging
 import optparse
 import os
 import sys
 import time
 import unittest
 
 try:
   import fcntl
 except ImportError:
   fcntl = None
 
 sys.path.insert(0, os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
 
 import subprocess2
 
+from testing_support import auto_stub
+
 # Method could be a function
 # pylint: disable=R0201
 
 
 def convert_to_crlf(string):
   """Unconditionally convert LF to CRLF."""
   return string.replace('\n', '\r\n')
 
 
 def convert_to_cr(string):
   """Unconditionally convert LF to CR."""
   return string.replace('\n', '\r')
 
 
 def convert_win(string):
   """Converts string to CRLF on Windows only."""
   if sys.platform == 'win32':
     return string.replace('\n', '\r\n')
   return string
 
 
-class DefaultsTest(unittest.TestCase):
-  # Can be mocked in a test.
-  TO_SAVE = {
-    subprocess2: [
-      'Popen', 'communicate', 'call', 'check_call', 'capture', 'check_output'],
-    subprocess2.subprocess.Popen: ['__init__', 'communicate'],
-  }
-
-  def setUp(self):
-    self.saved = {}
-    for module, names in self.TO_SAVE.iteritems():
-      self.saved[module] = dict(
-          (name, getattr(module, name)) for name in names)
-    # TODO(maruel): Do a reopen() on sys.__stdout__ and sys.__stderr__ so they
-    # can be trapped in the child process for better coverage.
-
-  def tearDown(self):
-    for module, saved in self.saved.iteritems():
-      for name, value in saved.iteritems():
-        setattr(module, name, value)
-
-  @staticmethod
-  def _fake_communicate():
+class DefaultsTest(auto_stub.TestCase):
+  # TODO(maruel): Do a reopen() on sys.__stdout__ and sys.__stderr__ so they
+  # can be trapped in the child process for better coverage.
+  def _fake_communicate(self):
     """Mocks subprocess2.communicate()."""
     results = {}
     def fake_communicate(args, **kwargs):
       assert not results
       results.update(kwargs)
       results['args'] = args
       return ('stdout', 'stderr'), 0
-    subprocess2.communicate = fake_communicate
+    self.mock(subprocess2, 'communicate', fake_communicate)
     return results
 
-  @staticmethod
-  def _fake_Popen():
+  def _fake_Popen(self):
     """Mocks the whole subprocess2.Popen class."""
     results = {}
     class fake_Popen(object):
       returncode = -8
       def __init__(self, args, **kwargs):
         assert not results
         results.update(kwargs)
         results['args'] = args
       @staticmethod
       def communicate():
         return None, None
-    subprocess2.Popen = fake_Popen
+    self.mock(subprocess2, 'Popen', fake_Popen)
     return results
 
-  @staticmethod
-  def _fake_subprocess_Popen():
+  def _fake_subprocess_Popen(self):
     """Mocks the base class subprocess.Popen only."""
     results = {}
     def __init__(self, args, **kwargs):
       assert not results
       results.update(kwargs)
       results['args'] = args
     def communicate():
       return None, None
-    subprocess2.subprocess.Popen.__init__ = __init__
-    subprocess2.subprocess.Popen.communicate = communicate
+    self.mock(subprocess2.subprocess.Popen, '__init__', __init__)
+    self.mock(subprocess2.subprocess.Popen, 'communicate', communicate)
     return results
 
   def test_check_call_defaults(self):
     results = self._fake_communicate()
     self.assertEquals(
         ('stdout', 'stderr'), subprocess2.check_call_out(['foo'], a=True))
     expected = {
         'args': ['foo'],
         'a':True,
     }
@@ skipping 281 matching lines @@
   return options.return_value
 
 
 if __name__ == '__main__':
   logging.basicConfig(level=
       [logging.WARNING, logging.INFO, logging.DEBUG][
         min(2, sys.argv.count('-v'))])
   if len(sys.argv) > 1 and sys.argv[1] == '--child':
     sys.exit(child_main(sys.argv[2:]))
   unittest.main()