combine base_unittest.py modules from gm and tools

gm/rebaseline_server/base_unittest.py

 #!/usr/bin/python
 
 """
 Copyright 2014 Google Inc.
 
 Use of this source code is governed by a BSD-style license that can be
 found in the LICENSE file.
 
 A wrapper around the standard Python unittest library, adding features we need
 for various unittests within this directory.
 """
 
-import filecmp
+# System-level imports.
 import os
-import shutil
-import tempfile
-import unittest
+import sys
 
-PARENT_DIR = os.path.dirname(os.path.realpath(__file__))
-TRUNK_DIR = os.path.dirname(os.path.dirname(PARENT_DIR))
-TESTDATA_DIR = os.path.join(PARENT_DIR, 'testdata')
-OUTPUT_DIR_ACTUAL = os.path.join(TESTDATA_DIR, 'outputs', 'actual')
-OUTPUT_DIR_EXPECTED = os.path.join(TESTDATA_DIR, 'outputs', 'expected')
+PARENT_DIR = os.path.abspath(os.path.dirname(__file__))
+TRUNK_DIR = os.path.abspath(os.path.join(PARENT_DIR, os.pardir, os.pardir))
+
+# Import the superclass base_unittest module from the tools dir.
+TOOLS_DIR = os.path.join(TRUNK_DIR, 'tools')
+if TOOLS_DIR not in sys.path:
+  sys.path.append(TOOLS_DIR)
+import tests.base_unittest as superclass_module
 
 
-class TestCase(unittest.TestCase):
+class TestCase(superclass_module.TestCase):
 
-  def setUp(self):
-    # Get the name of this test, in such a way that it will be consistent
-    # regardless of the directory it is run from (throw away package names,
-    # if any).
-    test_name = '.'.join(self.id().split('.')[-3:])
+  def __init__(self, *args, **kwargs):
+    super(TestCase, self).__init__(*args, **kwargs)
+    # Some of the tests within this package want their output validated,
+    # so we declare where the expected and actual output will be.
+    self._testdata_dir = os.path.join(PARENT_DIR, 'testdata')
 
-    self._input_dir = os.path.join(TESTDATA_DIR, 'inputs')
-    self._output_dir_actual   = os.path.join(OUTPUT_DIR_ACTUAL, test_name)
-    self._output_dir_expected = os.path.join(OUTPUT_DIR_EXPECTED, test_name)
-    create_empty_dir(self._output_dir_actual)
-    self._temp_dir = tempfile.mkdtemp()
-
-  def tearDown(self):
-    shutil.rmtree(self._temp_dir)
-    if os.path.exists(self._output_dir_expected):
-      different_files = find_different_files(self._output_dir_actual,
-                                             self._output_dir_expected)
-      # Maybe we should move this assert elsewhere?  It's unusual to see an
-      # assert within tearDown(), but my thinking was:
-      # 1. Every test case will have some collection of output files that need
-      #    to be validated.
-      # 2. So put that validation within tearDown(), which will be called after
-      #    every test case!
-      #
-      # I have confirmed that the test really does fail if this assert is
-      # triggered.
-      #
-      # Ravi notes: if somebody later comes along and adds cleanup code below
-      # this assert, then if tests fail, the artifacts will not be cleaned up.
-      assert (not different_files), \
-        ('found differing files:\n' +
-         '\n'.join(['tkdiff %s %s &' % (
-             os.path.join(self._output_dir_actual, basename),
-             os.path.join(self._output_dir_expected, basename))
-                    for basename in different_files]))
-
-  def shortDescription(self):
-    """Tell unittest framework to not print docstrings for test cases."""
-    return None
-
-  def find_path_to_program(self, program):
-    """Returns path to an existing program binary.
-
-    Args:
-      program: Basename of the program to find (e.g., 'render_pictures').
-
-    Returns:
-      Absolute path to the program binary, as a string.
-
-    Raises:
-      Exception: unable to find the program binary.
-    """
-    possible_paths = [os.path.join(TRUNK_DIR, 'out', 'Release', program),
-                      os.path.join(TRUNK_DIR, 'out', 'Debug', program),
-                      os.path.join(TRUNK_DIR, 'out', 'Release',
-                                   program + '.exe'),
-                      os.path.join(TRUNK_DIR, 'out', 'Debug',
-                                   program + '.exe')]
-    for try_path in possible_paths:
-      if os.path.isfile(try_path):
-        return try_path
-    raise Exception('cannot find %s in paths %s; maybe you need to '
-                    'build %s?' % (program, possible_paths, program))
-
-
-def create_empty_dir(path):
-  """Create an empty directory at the given path."""
-  if os.path.isdir(path):
-    shutil.rmtree(path)
-  elif os.path.lexists(path):
-    os.remove(path)
-  os.makedirs(path)
-
-
-def find_different_files(dir1, dir2, ignore_subtree_names=None):
-  """Returns a list of any files that differ between the directory trees rooted
-  at dir1 and dir2.
-
-  Args:
-    dir1: root of a directory tree; if nonexistent, will raise OSError
-    dir2: root of another directory tree; if nonexistent, will raise OSError
-    ignore_subtree_names: list of subtree directory names to ignore;
-          defaults to ['.svn'], so all SVN files are ignores
-
-  TODO(epoger): include the dirname within each filename (not just the
-  basename), to make it easier to locate any differences
-  """
-  differing_files = []
-  if ignore_subtree_names is None:
-    ignore_subtree_names = ['.svn']
-  dircmp = filecmp.dircmp(dir1, dir2, ignore=ignore_subtree_names)
-  differing_files.extend(dircmp.left_only)
-  differing_files.extend(dircmp.right_only)
-  differing_files.extend(dircmp.common_funny)
-  differing_files.extend(dircmp.diff_files)
-  differing_files.extend(dircmp.funny_files)
-  for common_dir in dircmp.common_dirs:
-    differing_files.extend(find_different_files(
-        os.path.join(dir1, common_dir), os.path.join(dir2, common_dir)))
-  return differing_files
-
-
-def main(test_case_class):
-  """Run the unit tests within the given class."""
-  suite = unittest.TestLoader().loadTestsFromTestCase(test_case_class)
-  unittest.TextTestRunner(verbosity=2).run(suite)
+def main(*args, **kwargs):
+  superclass_module.main(*args, **kwargs)