1#!/usr/bin/python
2
3"""
4Copyright 2014 Google Inc.
5
6Use of this source code is governed by a BSD-style license that can be
7found in the LICENSE file.
8
9A wrapper around the standard Python unittest library, adding features we need
10for various unittests within this directory.
11
12TODO(epoger): Move this into the common repo for broader use?  Or at least in
13a more common place within the Skia repo?
14"""
15
16import errno
17import filecmp
18import os
19import shutil
20import tempfile
21import unittest
22
23TRUNK_DIR = os.path.abspath(os.path.join(
24    os.path.dirname(__file__), os.pardir, os.pardir))
25
26
27class TestCase(unittest.TestCase):
28
29  def __init__(self, *args, **kwargs):
30    super(TestCase, self).__init__(*args, **kwargs)
31    # Subclasses should override this default value if they want their output
32    # to be automatically compared against expectations (see setUp and tearDown)
33    self._testdata_dir = None
34
35  def setUp(self):
36    """Called before each test."""
37    # Get the name of this test, in such a way that it will be consistent
38    # regardless of the directory it is run from (throw away package names,
39    # if any).
40    self._test_name = '.'.join(self.id().split('.')[-3:])
41
42    self._temp_dir = tempfile.mkdtemp()
43    if self._testdata_dir:
44      self.create_empty_dir(self.output_dir_actual)
45
46  def tearDown(self):
47    """Called after each test."""
48    shutil.rmtree(self._temp_dir)
49    if self._testdata_dir and os.path.exists(self.output_dir_expected):
50      different_files = _find_different_files(self.output_dir_actual,
51                                              self.output_dir_expected)
52      # Don't add any cleanup code below this assert!
53      # Then if tests fail, the artifacts will not be cleaned up.
54      assert (not different_files), \
55        ('found differing files:\n' +
56         '\n'.join(['tkdiff %s %s &' % (
57             os.path.join(self.output_dir_actual, basename),
58             os.path.join(self.output_dir_expected, basename))
59                    for basename in different_files]))
60
61  @property
62  def temp_dir(self):
63    return self._temp_dir
64
65  @property
66  def input_dir(self):
67    assert self._testdata_dir, 'self._testdata_dir must be set'
68    return os.path.join(self._testdata_dir, 'inputs')
69
70  @property
71  def output_dir_actual(self):
72    assert self._testdata_dir, 'self._testdata_dir must be set'
73    return os.path.join(
74        self._testdata_dir, 'outputs', 'actual', self._test_name)
75
76  @property
77  def output_dir_expected(self):
78    assert self._testdata_dir, 'self._testdata_dir must be set'
79    return os.path.join(
80        self._testdata_dir, 'outputs', 'expected', self._test_name)
81
82  def shortDescription(self):
83    """Tell unittest framework to not print docstrings for test cases."""
84    return None
85
86  def create_empty_dir(self, path):
87    """Creates an empty directory at path and returns path.
88
89    Args:
90      path: path on local disk
91    """
92    # Delete the old one, if any.
93    if os.path.isdir(path):
94      shutil.rmtree(path=path, ignore_errors=True)
95    elif os.path.lexists(path):
96      os.remove(path)
97
98    # Create the new one.
99    try:
100      os.makedirs(path)
101    except OSError as exc:
102      # Guard against race condition (somebody else is creating the same dir)
103      if exc.errno != errno.EEXIST:
104        raise
105    return path
106
107
108def _find_different_files(dir1, dir2, ignore_subtree_names=None):
109  """Returns a list of any files that differ between the directory trees rooted
110  at dir1 and dir2.
111
112  Args:
113    dir1: root of a directory tree; if nonexistent, will raise OSError
114    dir2: root of another directory tree; if nonexistent, will raise OSError
115    ignore_subtree_names: list of subtree directory names to ignore;
116          defaults to ['.svn'], so all SVN files are ignores
117
118  TODO(epoger): include the dirname within each filename (not just the
119  basename), to make it easier to locate any differences
120  """
121  differing_files = []
122  if ignore_subtree_names is None:
123    ignore_subtree_names = ['.svn']
124  dircmp = filecmp.dircmp(dir1, dir2, ignore=ignore_subtree_names)
125  differing_files.extend(dircmp.left_only)
126  differing_files.extend(dircmp.right_only)
127  differing_files.extend(dircmp.common_funny)
128  differing_files.extend(dircmp.diff_files)
129  differing_files.extend(dircmp.funny_files)
130  for common_dir in dircmp.common_dirs:
131    differing_files.extend(_find_different_files(
132        os.path.join(dir1, common_dir), os.path.join(dir2, common_dir)))
133  return differing_files
134
135
136def main(test_case_class):
137  """Run the unit tests within the given class.
138
139  Raises an Exception if any of those tests fail (in case we are running in the
140  context of run_all.py, which depends on that Exception to signal failures).
141  """
142  suite = unittest.TestLoader().loadTestsFromTestCase(test_case_class)
143  results = unittest.TextTestRunner(verbosity=2).run(suite)
144  if not results.wasSuccessful():
145    raise Exception('failed unittest %s' % test_case_class)
146