Make blink_trybot recipe work on windows

scripts/slave/unittests/recipes_test.py

 #!/usr/bin/python
 # Copyright (c) 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.
 
 """Provides test coverage for individual recipes.
 
 Recipe tests are located in ../recipes_test/*.py.
 
 Each py file's splitext'd name is expected to match a recipe in ../recipes/*.py.
@@ skipping 23 matching lines @@
 
 Additionally, this test cannot pass unless every recipe in ../recipes has 100%
 code coverage when executed via the tests in ../recipes_test.
 """
 
 import collections
 import contextlib
 import json
 import os
 import sys
-import unittest
 
 from glob import glob
 
 import test_env  # pylint: disable=W0611
 
 import coverage
 
+import common.python26_polyfill  # pylint: disable=W0611
+import unittest
+
 from common import annotator
 
 SCRIPT_PATH = os.path.abspath(os.path.dirname(__file__))
 ROOT_PATH = os.path.abspath(os.path.join(SCRIPT_PATH, os.pardir, os.pardir,
                                          os.pardir))
 SLAVE_DIR = os.path.join(ROOT_PATH, 'slave', 'fake_slave', 'build')
 INTERNAL_DIR = os.path.join(ROOT_PATH, os.pardir, 'build_internal')
 BASE_DIRS = {
     'Public': os.path.dirname(SCRIPT_PATH),
     'Internal': os.path.join(INTERNAL_DIR, 'scripts', 'slave'),
@@ skipping 129 matching lines @@
 
 
 def train_from_tests(recipe_path):
   for path in glob(expected_for(recipe_path, '*')):
     os.unlink(path)
 
   for name, test_data in exec_test_file(recipe_path):
     steps = execute_test_case(test_data, recipe_path)
     expected_path = expected_for(recipe_path, name)
     print 'Writing', expected_path
-    with open(expected_path, 'w') as f:
+    with open(expected_path, 'wb') as f:
       f.write('[')
       first = True
       for step in steps:
         f.write(('' if first else '\n  },')+'\n  {')
         first_dict_item = True
         for key, value in sorted(step.items(), key=lambda x: x[0]):
           f.write(('' if first_dict_item else ',')+'\n   ')
           f.write('"%s": ' % key)
           json.dump(value, f, sort_keys=True)
           first_dict_item = False
         first = False
       f.write('\n  }\n]')
 
   return True
 
 
 def load_tests(loader, _standard_tests, _pattern):
   """This method is invoked by unittest.main's automatic testloader."""
   def create_test_class(recipe_path):
     class RecipeTest(unittest.TestCase):
       @classmethod
       def add_test_methods(cls):
         for name, test_data in exec_test_file(recipe_path):
           expected_path = expected_for(recipe_path, name)
           def add_test(test_data, expected_path):
             def test_(self):
               steps = execute_test_case(test_data, recipe_path)
               # Roundtrip json to get same string encoding as load
               steps = json.loads(json.dumps(steps))
-              with open(expected_path, 'r') as f:
+              with open(expected_path, 'rb') as f:
                 expected = json.load(f)
               self.assertEqual(steps, expected)
             test_.__name__ += name
             setattr(cls, test_.__name__, test_)
           add_test(test_data, expected_path)
 
     RecipeTest.add_test_methods()
 
     RecipeTest.__name__ += '_for_%s' % (
       os.path.splitext(os.path.basename(recipe_path))[0])
@@ skipping 52 matching lines @@
     total_covered = COVERAGE.report()
     if total_covered != 100.0:
       print 'FATAL: Recipes are not at 100% coverage.'
       retcode = retcode or 2
 
   return retcode
 
 
 if __name__ == '__main__':
   sys.exit(main(sys.argv))